JP2009069734A - Destaticizing device, and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the position and the width of the irradiation range of light, with respect to a photoreceptor from being dispersed in each static destaticizing device. <P>SOLUTION: The first destaticizing device 80 has a light guide panel 120, a light source unit 110 and a direction regulating mechanism 130. The light guide panel 120 has an incident face 121 and irradiates a photoreceptor drum 17 with a light, by emitting the light based on a light beam incident from the incident face 121. The light source unit 110 emits a light beam directed toward the incident face 121. The direction regulating mechanism 130 adjusts the advancing direction of the light beam emitted from the light source unit 110. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a static eliminator that removes electric charges on a surface of a photoconductor provided in an electrophotographic image forming apparatus by irradiating the surface with light.

  In addition to the photosensitive drum, the exposure device, the charging device, the developing device, the transfer device, the cleaning device, the fixing device, and the like, the electrophotographic image forming apparatus includes a static eliminator. There are various types of static eliminators, but a light irradiation type is often used in which the surface of the photosensitive drum is removed by irradiating the surface of the photosensitive drum with light.

As a light irradiation type static eliminator, one using a light guide plate is known. In a static eliminator using a light guide plate, light emitted from a light emitting device such as an LED enters the light guide plate, the light guide plate emits surface light by the incident light, and the light emitted from the light guide plate is emitted to the photosensitive drum. Irradiated. A typical example of a static eliminator using a light guide plate (light guide) is shown in FIG.
JP 2004-70364 A (publication date: March 4, 2004)

  By the way, there is a manufacturing error in the light emitting device, and the traveling direction of the light beam emitted from the light emitting portion (PN junction in the case of LED) inside the light emitting device is slightly different for each light emitting device. Therefore, no matter how much the mounting position accuracy of the light emitting device with respect to the incident surface of the light guide plate is improved, it is not possible to eliminate the variation in the traveling direction of the light beam emitted from the light emitting unit inside the light emitting device. As a result, the traveling direction of the light beam emitted from the light emitting device varies among the static eliminators, and due to this variation, the position and width of the irradiation range of the light radiated from the light guide plate to the photosensitive drum varies. There was a problem that it fluctuated every time. When such a problem occurs, naturally, a situation occurs in which the charge eliminating function required in the image forming process cannot be obtained.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a static eliminator capable of suppressing variations in the position and area of the light irradiation range with respect to the photoreceptor between the static eliminators. .

  In order to achieve the above object, the present invention has an incident surface in a static eliminator that removes charges from a photosensitive drum by irradiating light to the photosensitive drum provided in the electrophotographic image forming apparatus. A light guide plate that emits light to the photosensitive drum by emitting light based on a light beam incident from the incident surface, a light source device that emits a light beam toward the incident surface, and a light beam emitted from the light source device. And a direction adjustment mechanism that adjusts the traveling direction.

  According to the above configuration, since the traveling direction of the light beam emitted from the light source device can be adjusted for each static elimination device, the traveling direction of the light beam emitted from the light source device can be made uniform among the static elimination devices. Therefore, the width of the irradiation range of the light emitted from the light guide plate can be made uniform between the static eliminators, and it is possible to suppress the variation in the position and the width of the light irradiation range with respect to the photosensitive drum between the static eliminators. There is an effect.

  Further, the static eliminator of the present invention, in addition to the above configuration, the light source device includes a light emitting element that emits the light beam and a holding member that holds the light emitting element while being fixed, and the direction adjusting mechanism includes It is preferable that the rotating mechanism rotate the holding member so that the traveling direction is adjusted. This makes it possible to easily change (adjust) the traveling direction of the light beam emitted from the light source device.

  Furthermore, in the static eliminator of the present invention, the rotating mechanism has one end fixed to the outer surface of the holding member, a shaft serving as a rotating shaft in the rotating mechanism, a bearing that supports the shaft, A configuration may be provided that includes a switching member that switches between a fixed state in which the shaft is fixed to the bearing and a rotatable state in which the shaft is supported by the bearing so that the shaft can rotate.

  In the static eliminator of the present invention, the rotation mechanism has one end fixed to the outer surface of the holding member, a shaft that serves as a rotation shaft in the rotation mechanism, a bearing that supports the shaft, An eccentric cam having an axis parallel to the rotation axis as a center of rotation, and the holding member and a wall surface of the image forming apparatus, are inserted between the holding member and the wall surface of the image forming apparatus. The structure which has an elastic member made to contact | abut may be sufficient.

  In addition, a photosensitive drum is provided, and a charging unit that charges the photosensitive drum in order from the upstream side in the rotation direction of the photosensitive drum around the photosensitive drum, and the charged photosensitive drum is exposed and latently exposed. An exposure unit that forms an image, a developing unit that develops the latent image, a transfer unit that transfers an image developed by the developing unit to a sheet, and the peripheral surface of the photosensitive drum after the transfer. In an electrophotographic image forming apparatus in which a cleaning unit for removing toner is set, around the photosensitive drum, upstream of the charging unit in the rotation direction and the rotation of the cleaning unit It is preferable to arrange the static eliminator on the downstream side in the direction. According to the above configuration, the static eliminator erases the electrostatic latent image remaining on the outer peripheral surface of the photosensitive drum after transfer, so that the influence of the previous image forming process is influenced in the next image forming process. It will bear the function to prevent it from reaching.

  In addition, a photosensitive drum is provided, and a charging unit that charges the photosensitive drum in order from the upstream side in the rotation direction of the photosensitive drum around the photosensitive drum, and the charged photosensitive drum is exposed and latently exposed. An exposure unit that forms an image, a developing unit that develops the latent image, a transfer unit that transfers an image developed by the developing unit to a sheet, and the peripheral surface of the photosensitive drum after the transfer. In an electrophotographic image forming apparatus in which a cleaning unit for removing toner is set, around the photosensitive drum and upstream of the transfer unit in the rotation direction and the rotation of the developing unit It is preferable to arrange the static eliminator on the downstream side in the direction. According to the above configuration, the static eliminator reduces the potential of the outer peripheral surface of the photosensitive drum before the transfer process, so that the sheet is attracted to the photosensitive drum by the potential of the photosensitive drum in the transfer unit. It will be responsible for the function to suppress.

  As described above, the present invention relates to a static eliminator that removes charges from the photosensitive drum by irradiating light to the photosensitive drum provided in the electrophotographic image forming apparatus. A light guide plate that emits light to the photosensitive drum by emitting light based on a light beam incident from the light source, a light source device that emits the light beam toward the incident surface, and a traveling direction of the light beam emitted from the light source device And a direction adjusting mechanism.

  Therefore, the width of the irradiation range of the light emitted from the light guide plate can be made uniform between the static eliminators, and the variation in the position and width of the light irradiation range with respect to the photosensitive drum between the static eliminators can be suppressed. There is an effect.

  An image forming apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating an image forming apparatus 11 according to the present embodiment.

  The image forming apparatus 11 is an electrophotographic printer that forms a monochrome image (monochromatic and black image) on a sheet based on digital image data received from an external apparatus.

  As shown in FIG. 1, the image forming apparatus 11 includes an exposure device 13, a developing device 15, a photosensitive drum 17, a charger 19, a cleaner unit 21, a fixing unit 23, a paper feed tray 25, a registration roller 29, a paper feed transport. A path 27, a paper transport path 31, a paper discharge tray 33, and the like. The paper feed conveyance path 27 is a path formed in a range from the paper feed tray 25 to the position where the registration rollers 29 are arranged. The sheet conveyance path 31 is a path formed from the position where the registration roller 29 is disposed to the sheet discharge tray 33 via the image transfer unit 47 and the fixing unit 23.

  The charger 19 is a charging unit for uniformly charging the outer peripheral surface of the rotating photosensitive drum 17 to a predetermined potential, and the charger 19 is used in the image forming apparatus 11 of FIG. Alternatively, a roller-type charger or a brush-type charger configured to be in contact with the photosensitive drum 17 may be used.

  The exposure device 13 is a laser scanning unit (LSU) including a laser irradiation unit 35 and a reflection mirror 37. The exposure device 13 exposes the outer peripheral surface of the photosensitive drum 17 uniformly charged by the charger 19 in accordance with the input image data, so that the outer peripheral surface of the photosensitive drum 17 corresponds to the input image data. An electrostatic latent image is formed. In the present embodiment, the two-beam laser scanning unit is used as the exposure device 13 in order to prevent the irradiation speed of the laser light source from becoming too high in high-speed printing. However, the exposure apparatus 13 is not limited to the laser scanning unit, and may be a unit in which EL (electroluminescence), LED (light emitting diode), and the like are arranged in an array.

  The developing device 15 develops (develops) the electrostatic latent image by supplying toner to the electrostatic latent image formed on the outer peripheral surface of the photosensitive drum 17. The cleaner unit 21 removes or collects toner remaining on the outer peripheral surface of the photosensitive drum 17 after development and image transfer.

  The toner image (image) visualized on the outer peripheral surface of the photosensitive drum (photosensitive material) 17 is transferred onto a sheet by the image transfer unit 47. The transfer mechanism 39 for performing the transfer is applied with an electric field having a polarity opposite to the polarity of the electric charge charged on the toner adhering to the outer peripheral surface of the photoconductor drum 17. The toner adhering to the outer peripheral surface of the drum 17 is transferred to the paper. For example, when the toner on the outer peripheral surface of the photosensitive drum 17 has a negative polarity charge, the polarity of the electric field applied to the transfer mechanism 39 is a positive polarity.

  The transfer mechanism 39 includes a driving roller 41, a driven roller 43, an elastic conductive roller 49, other rollers, and a transfer belt 45 that spans these rollers.

The transfer belt 45 is a belt member having a volume resistance value of 1 × 10 ⁹ Ω · cm to 1 × 10 ¹³ Ω · cm. Further, an elastic conductive roller 49 for applying a transfer electric field is disposed in the vicinity of the image transfer portion 47 that is a region where the photosensitive drum 17 and the transfer belt 45 are in contact with each other.

  The elastic conductive roller 49 presses the transfer belt 45 and the photosensitive drum 17 so as to press the transfer belt 45 against the photosensitive drum 17. As a result, the image transfer portion 47 (transfer nip portion), which is a contact area between the photosensitive drum 17 and the transfer belt 45, is not a linear shape but a surface shape having a predetermined width. Therefore, the transfer efficiency to the conveyed paper can be improved.

  Further, on the downstream side of the image transfer unit 47 in the paper conveyance direction, a charge removal process is performed on the paper charged when passing through the image transfer unit 47 so that the paper is smoothly conveyed to the fixing unit 23. A static eliminating roller 51 is disposed. The neutralizing roller 51 is disposed on the back surface of the transfer belt 45.

  Further, the transfer mechanism 39 is provided with a cleaning unit 53 that removes toner stains on the transfer belt 45 and a static elimination mechanism 55 that performs static elimination processing on the transfer belt 45. As a static elimination method by the static elimination mechanism 55, there is a method of grounding the transfer belt 45 through an apparatus, or a method of applying an electric field having a polarity opposite to the polarity of the transfer electric field to the transfer belt 45. The sheet on which the toner image (image) is transferred by the transfer mechanism 39 is conveyed to the fixing unit 23.

  The fixing unit 23 includes a heating roller 57 and a pressure roller 59, and a sheet peeling claw 61, a thermistor 63 (roller surface temperature detection member), and a roller surface cleaning member 65 are disposed around the heating roller 57. . A heat source 67 for heating the outer peripheral surface of the roller to a predetermined temperature (fixing set temperature: approximately 160 to 200 ° C.) is disposed inside the heating roller 57.

  At both ends in the axial direction of the pressure roller 59, a mechanism such as a load spring is provided, and the pressure roller 59 is pressed against the heating roller 57 with a predetermined load by this mechanism. Further, similarly to the periphery of the heating roller 57, a sheet peeling claw and a roller surface cleaning member are disposed around the pressure roller 59.

  In the fixing unit 23, an unfixed toner image on the sheet is formed by a fixing processing unit, which is a pressure contact portion between the heating roller 57 and the pressure roller 59, by the surface temperature of the heating roller 57 and the pressure contact force by the pressure roller 59. It is heat-fixed on the paper.

  The paper feed tray 25 is a tray for storing paper used for printing (printing paper). In the image forming apparatus 11 of this embodiment, an image including the photosensitive drum 17 and the transfer mechanism 39 is used. It is provided below the formation part. In the image forming apparatus 11 of the present embodiment, a plurality of paper feed trays 25 capable of storing 500 to 1500 fixed-size sheets are arranged so that continuous printing can be performed even for an extremely large amount of sheets. ing. Further, on the side of the apparatus, a large-capacity paper feed cassette 73 capable of storing a large number of different types of paper and a manual feed tray 75 mainly used for printing on irregular-size paper are arranged. Has been.

  The paper discharge tray 33 is disposed on the side of the apparatus opposite to the manual feed tray 75. However, the paper discharge tray 33 is removed, and a post-processing device (stapling, punching, etc.) of discharged paper or a multi-stage paper discharge is performed. The tray can be arranged as an option.

  Further, the image forming apparatus 11 is provided with a control unit for controlling the operation of the image forming apparatus 11. The control unit includes, for example, a microcomputer, a ROM (Read Only Memory) that stores a control program indicating a procedure of processing executed by the microcomputer, and a RAM (Random Access Memory) that provides a work area for work. , A non-volatile memory that backs up and holds data necessary for control, a circuit for inputting signals from sensors and switches, including an input buffer and an A / D conversion circuit, a motor, a solenoid, a lamp, etc. And an output circuit including a driver for driving the.

  Next, the sheet conveyance executed in the image forming apparatus 11 will be described in detail. First, the control unit selects the paper feed tray 25 in which the paper to be transported is stored, and controls the operation of each roller provided along the paper feed transport path 27 to thereby select the selected paper feed. The paper stored in the paper tray 25 is conveyed toward the registration roller 29. As a result, the sheet reaches before the registration roller 29 and stops temporarily.

  Next, the control unit conveys the sheet to the image transfer unit 47 by re-rotating the registration roller 29 at a timing such that the leading end of the sheet overlaps the leading end of the image formed on the outer periphery of the photosensitive drum 17. To do. Then, an image (toner image) is transferred onto the paper by the transfer mechanism 39, and then the paper is guided to the fixing unit 23, and the image made of toner transferred onto the paper is fixed on the paper, and the paper discharge tray 33. To be discharged.

  Further, the control unit switches the conveyance path from the fixing unit 23 to the paper discharge tray 33 according to the difference between the print mode (copier mode, printer mode, FAX mode, etc.) and the print processing method (single-sided printing / double-sided printing). .

  Usually, in the copier mode, since the user performs an operation near the apparatus, the sheet is often discharged with the printing surface facing upward. This is called “face-up discharge”. On the other hand, in each of the printer and FAX modes, since the user is not in the vicinity of the apparatus, the “face-down discharge” method for aligning the page order of discharged sheets is often used. The image forming apparatus 11 has a mechanism capable of switching between face-up discharge and face-down discharge according to the print mode. The switching mechanism is composed of a plurality of transport paths and a plurality of branch claws arranged between the fixing unit 23 and the paper discharge tray 33, and discharges paper according to the print mode.

  Further, as shown in FIG. 1, the image forming apparatus 11 of the present exemplary embodiment includes a first static elimination device 80 and a second static elimination device 180 around the photosensitive drum 17.

  The first static elimination device 80 is disposed downstream of the cleaner unit 21 in the rotation direction 220 of the photosensitive drum 17 and upstream of the charger 19 in the rotation direction 220. After the residual toner is removed by the cleaner unit 21 and the charger 19. By irradiating light to the outer peripheral surface of the photosensitive drum 17 before the charging process according to the above, charges are removed from the outer peripheral surface. Thereby, the history of the electrostatic latent image remaining on the outer peripheral surface of the photosensitive drum 17 can be erased, and the influence of the previous image forming process is prevented in the next image forming process.

  The second static elimination device 180 is disposed downstream of the developing device 15 in the rotation direction 220 and upstream of the image transfer unit 47 in the rotation direction 220, and is the outer peripheral surface of the photosensitive drum 17 after the development process and before the transfer process. By irradiating with light, a part of the electric charge is removed from the outer peripheral surface, and the potential of the outer peripheral surface is lowered. As a result, the sheet is prevented from being attracted to the photosensitive drum 17 by the potential of the photosensitive drum 17 in the image transfer unit 47.

  Next, the configuration of the first static elimination device 80 will be described in detail. In addition, since the 1st static elimination apparatus 80 and the 2nd static elimination apparatus 180 are the same structures, below, only the structure of the 1st static elimination apparatus 80 is demonstrated, and description of the structure of the 2nd static elimination apparatus 180 is abbreviate | omitted.

  FIG. 2 is a perspective view showing the photosensitive drum 17 and the first static elimination device 80. 3 is a cross-sectional view of the photosensitive drum 17 and the first static elimination device 80 cut along a plane parallel to the A direction and the B direction shown in FIG. Note that the A direction is a direction parallel to the axial direction of the photosensitive drum 17, and the B direction is perpendicular to the A direction and faces the photosensitive drum 17 in the light guide plate 120 described later (see FIG. 3 is a direction perpendicular to the light emitting surface 122).

  As shown in FIGS. 2 and 3, the first static elimination device 80 is configured to include a light source unit 110 and a light guide plate 120. As illustrated in FIG. 3, the light source unit 110 includes an LED (light emitting diode) 111 and a housing case 112 that houses the LED 111.

  The light guide plate 120 is a wedge-shaped glass member (or transmissive resin), guides the incident light along the A direction, and against the charged region on the outer peripheral surface of the photosensitive drum 17 by the incident light. It is formed so as to emit surface light. The charging area is an area that can be charged by the charger 19 on the outer peripheral surface of the photosensitive drum 17.

  Specifically, the light guide plate 120 is formed at an end portion of the light guide plate 120 and is formed so as to extend along the A direction and an incident surface 121 through which light enters the light guide plate 120 and the photosensitive drum. 17 has a light emitting surface 122 opposed to the outer peripheral surface 17 and a reflecting surface 123 that diffusely reflects light inside the light guide plate 120. The reflecting surface 123 is a wall surface on which aluminum vapor deposition is performed or a roughened wall surface inside the light guide plate 120.

  Also, as shown in FIG. 3, among the light incident on the light emitting surface 122 from the inside of the light guide plate 120, light having an incident angle with respect to the light emitting surface 122 higher than a predetermined value is totally reflected by the light emitting surface 122. Light returned to the inside of the light guide plate 120 and having an incident angle with respect to the light emitting surface 122 lower than a predetermined value is transmitted through the light emitting surface 122 and guided to the outer peripheral surface of the photosensitive drum 17. This is due to the difference between the refractive index inside the light guide plate 120 and the external refractive index.

  The LED 111 is a light source that is disposed so as to face the incident surface 121 of the light guide plate 120 and that enters the light guide plate 120 through the incident surface 121. Further, in FIG. 3, reference numeral 111b is a PN junction (semiconductor layer) inside the LED 111, which is a portion that becomes a light emission source (bright spot).

  The housing case 112 is a cylindrical member having an opening, and fixes and houses (holds) the LED 111 inside the case. The light beam emitted from the LED 111 is guided into the light guide plate 120 through the opening and the incident surface 121.

  According to the configuration described above, as shown in FIG. 3, the light beam guided into the light guide plate 120 travels into the light guide plate 120 and immediately approaches the front side of the light guide plate 120 (side closer to the incident surface 121). In addition to the light beam 161 that is guided to the reflection surface 123 and diffusely reflected by the reflection surface 123, the light beam 161 travels into the light guide plate 120 and then enters the light emission surface 122 at a low incident angle. Also included is a light beam 160 that is totally reflected, travels inside the light guide plate 120 by this total reflection, and is guided to the reflection surface 123 on the back side (the side away from the incident surface 121) of the light guide plate 120 and diffusely reflects. Thereby, irregular reflection of light occurs over almost the entire reflecting surface 123, and light with a high incident angle is incident over almost the entire light emitting surface 122 due to this irregular reflection. Therefore, light is transmitted over almost the entire light emitting surface 122, and the transmitted light is guided to the charging area of the photosensitive drum 17, and the entire charging area on the photosensitive drum 17 is uniformly irradiated with light. Is done.

  Incidentally, there is a manufacturing error in the LED 111, and the traveling direction of the light beam emitted from the PN junction 111b inside the LED 111 varies from LED to LED. Therefore, no matter how much the mounting position accuracy of the LED 111 with respect to the incident surface 121 is improved, the variation in the traveling direction of the light beam emitted from the PN junction cannot be eliminated. As a result, the traveling direction of the light beam emitted from the LED 111 varies for each static eliminator, so that the width and position of the irradiation range of the light irradiated from the light emitting surface 122 of the light guide plate 120 to the photosensitive drum 17 are determined. There arises a problem that it varies every time. Hereinafter, this problem will be described in more detail.

  For example, as shown in FIG. 4, it is assumed that a static eliminator 80a having the same configuration as that of the first static eliminator 80 (FIG. 3) is manufactured. That is, the static eliminator 80a shown in FIG. 4 includes the light guide plate 120a and the light source unit 110a, and includes the LED 111a, like the first static eliminator 80 in FIG. Further, the positional relationship (distance, orientation, etc.) between the incident surface 121a and the LED 111a in the static eliminator 80a in FIG. 4 is the same as the positional relationship between the light guide plate 120 and the LED 111 in the first static eliminator 80 in FIG. .

  However, since the traveling direction of the light beam emitted from the LED is slightly different for each LED, a situation occurs in which the traveling direction of the light beam emitted from the LED is different for each static elimination device. For example, in the first static elimination device 80 in FIG. 3, the light beam emitted from the LED 111 enters the light guide plate 120 while traveling along the direction A, whereas in the static elimination device 80 a in FIG. 4, the luminous flux is emitted from the LED 111. The light beam enters the light guide plate 120 while traveling in a direction inclined from the A direction.

  In the first static eliminator 80 of FIG. 3, light is emitted to the outside from almost the entire light emitting surface 122 of the light guide plate 120, and the entire charged region is uniformly irradiated with light, whereas the static eliminator of FIG. In 80a, the light emitting surface 122a of the light guide plate 120a has a wide area where light is not emitted, and a charged area and a light-irradiated area are generated, and a non-static area is generated in the charged area (static elimination). The inconvenience of “unevenness” is brought about.

  This is because in the static eliminator shown in FIGS. 3 and 4, the light guide plate is designed on the assumption that the light beam emitted from the LED travels along the A direction. More specifically, when a light beam traveling along the A direction is incident on the light guide plate, light is emitted uniformly from almost the entire light emitting surface 122 as shown in FIG. When the light beam traveling along the direction inclined from the A direction is incident on the light guide plate, as shown in FIG. 4, the region where the irregular reflection occurs inside the light guide plate 120 is reduced, and accordingly, the light emitting surface 122 has an external surface. This is because the area that emits light is reduced, and a part of the non-irradiated area that is not irradiated with light is generated in the charged area.

  When the above disadvantages are brought about, naturally, various problems occur in the image forming process. For example, if the above inconvenience occurs in the first static elimination device 80, the history of the electrostatic latent image remaining on the outer peripheral surface of the photosensitive drum 17 cannot be erased, and the previous image is formed in the next image forming process. The formation process is affected, and the print image quality deteriorates. Further, if the above-described inconvenience occurs in the second static elimination device 180, the sheet is attracted to the photosensitive drum 17 due to excessive electric charge on the outer periphery of the photosensitive drum 17, and a paper conveyance defect occurs.

  Therefore, in this embodiment, in order to suppress the above inconvenience, as shown in FIG. 5, a direction adjustment mechanism 130 that adjusts the traveling direction of the light beam emitted from the LED 111 by rotating the light source unit 110 described above is provided. I have. Hereinafter, the direction adjustment mechanism 130 will be described in detail. 5A is a cross-sectional view of the direction adjusting mechanism 130 and the light source unit 110 as viewed from the B direction side, and FIG. 5B is viewed from the C direction side orthogonal to the A direction and the B direction. It is a side view which shows the light source unit 110. FIG.

  The direction adjusting mechanism 130 is a mechanism for rotating the housing case 112, and the LED 111 fixed to the housing case 112 is also rotated by the rotation of the housing case 112. And if LED111 rotates, the direction of the light beam emitted from LED111 will change.

  As shown in FIG. 5A, the direction adjustment mechanism 130 has a first shaft 131, a second shaft 132, a first bearing 133, a second bearing 134, an adjustment knob 135, and a fastening screw 136. . In FIG. 2 and FIG. 5B, the first bearing 133, the second bearing 134, the adjustment knob 135, and the fastening screw 136 are omitted but actually exist.

  Further, as shown in FIG. 5A, the rotation axis of the housing case 112 is set in a direction parallel to the C direction so as to pass through the PN junction 111 b inside the LED 111.

  As shown in FIGS. 5A and 5B, the first shaft 131 and the second shaft 132 are arranged to face each other so as to sandwich the housing case 112, and both of the shafts are fixed to the housing case 112. Yes. The first shaft 131 and the second shaft 132 are fixed to the housing case 112 so that the axial direction of the shaft and the rotation axis of the housing case 112 coincide.

  The first bearing 133 is a member that supports the first shaft 131 so that the first shaft 131 can rotate. The second bearing 134 is a member that supports the second shaft 132 so that the second shaft 132 can rotate.

  The fastening screw 136 is fitted in the first bearing 133 so that the tip of the screw comes into contact with the first shaft 131. When the fastening screw 136 is tightened, the first shaft 131 and the housing case 112 are fixed to the first bearing 133 by pressing the first shaft 131 against the first bearing 133. Further, when the fastening screw is loosened, play occurs between the first shaft 131 and the first bearing 133, and the first shaft 131 and the housing case 112 are in a state of being rotatably supported by the first bearing 133. .

  The adjustment knob 135 is a handle attached to the end of the first shaft 131 opposite to the side connected to the housing case 112.

  In the above configuration, the housing case 112 is fixed to the first bearing 133 when the fastening screw 136 is tightened. However, when the fastening screw 136 is loosened by the operator, the housing case 112 is shown in FIG. The operator can rotate about the rotation axis shown in a), and the operator can rotate the accommodation case 112 by turning the adjustment knob 135.

  When the housing case 112 rotates, the LED 111 fixed to the housing case 112 also rotates. With this rotation, the traveling direction of the light beam emitted from the LED 111 fixed to the housing case 112 can be changed. . For example, as shown in FIG. 7A, even if the traveling direction of the light beam emitted from the LED 111 in the housing case 112 is inclined by a predetermined angle from the A direction, the housing case 112 is rotated by the predetermined angle. Then, as shown in FIG. 7B, the traveling direction of the light beam emitted from the LED 111 in the housing case 112 can be made parallel to the A direction.

  Therefore, when the light source unit 110 includes the direction adjusting mechanism 130 as in the present embodiment, the traveling direction of the light beam emitted from the LEDs 111 is a direction suitable for the light guide plate (in the present embodiment, between the plurality of static eliminators). A direction) can be made uniform, and each of the static eliminators can irradiate light uniformly over the entire charging region, and the situation that the width and position of the irradiation range with respect to the photosensitive drum 17 varies between the static eliminators can be suppressed. .

  Next, a modification of the direction adjustment mechanism will be described with reference to FIG. As shown in FIG. 6A, the direction adjusting mechanism 130a includes an eccentric cam 145 and an elastic member 140.

  Although omitted in FIG. 6, the first shaft 131, the second shaft 132, the first bearing 133, and the second bearing 134 shown in FIG. 5A are also included in the direction adjusting mechanism 130a of FIG. It is. However, in the direction adjustment mechanism 130a of FIG. 6, the fastening screw 136 is not provided, and the first shaft 131 is supported by the first bearing 133 in a rotatable state.

  The eccentric cam 145 is disposed so as to contact the outer peripheral surface of the housing case 112 with the axis parallel to the rotation axis as the center of rotation. The elastic member 140 is a coil spring, and has one end connected to the outer peripheral surface of the housing case 112 and the other end connected to the wall surface of the image forming apparatus 11. The elastic member 140 makes the housing case 112 abut on the outer periphery of the eccentric cam 145 by elastic force. 6 (a) and 6 (b), when the eccentric cam 145 rotates, the housing case 112 causes the first shaft 131 and the second shaft 132 to rotate about the rotation axis by the expansion and contraction force of the elastic member 140. It is supposed to rotate as. Thereby, as shown in FIG. 7, it is possible to change the traveling direction of the light beam emitted from the LED 111 in the housing case 112.

  According to the above embodiment, the first static elimination device 80 or the second static elimination device 180 irradiates the photosensitive drum 17 provided in the electrophotographic image forming apparatus 11 with light, and thereby charges from the photosensitive drum 17. A light guide plate 120 that emits light to the photosensitive drum 17 by emitting light based on the light beam incident from the incident surface 121, and a light source unit (light source device) 110 that emits the light beam toward the incident surface 121. And a direction adjustment mechanism 130 that adjusts the traveling direction of the light beam emitted from the light source unit 110. According to this configuration, the traveling direction of the light beam emitted from the light source unit 110 can be adjusted for each static eliminator. Therefore, the traveling direction of the light beam emitted from the light source unit 110 can be aligned between the static eliminators. Become. Therefore, the width of the irradiation range of the light emitted from the light guide plate 120 can be made uniform among the static eliminators, and the variation in the position and the width of the light irradiation range with respect to the photosensitive drum 17 between the static eliminators is suppressed. There is an effect that can be done.

  The light source unit 110 includes an LED (light emitting element) 111 that emits the luminous flux and a housing case (holding member) 112 that holds the LED 111 while fixing it, and the direction adjusting mechanism 130 adjusts the traveling direction of the luminous flux. As described above, the rotating mechanism rotates the housing case 112.

  Further, as shown in FIG. 5A, the direction adjusting mechanism 130 has one end fixed to the outer surface of the housing case 112 and a first shaft 131 serving as a rotating shaft in the rotating mechanism, and a first shaft. The first shaft 133 is supported by the first bearing 133 so that the first shaft 133 can be rotated, and the first shaft 133 is supported in a fixed state where the first shaft 131 is fixed to the first bearing 133. And a fastening screw 136 for switching between the rotatable state.

  Further, the image forming apparatus 11 of the present embodiment includes the photosensitive drum 17 and is charged with a charging unit that charges the photosensitive drum 17 in order from the upstream side in the rotation direction 220 around the photosensitive drum 17. An exposure unit that exposes the photosensitive drum 17 to form a latent image, a developing unit that develops the latent image, a transfer unit that transfers an image developed by the developing unit to a sheet, and the photoconductor after the transfer It can be said that a cleaning unit for removing the toner remaining on the peripheral surface of the drum 17 is set. The first static elimination device 80 is disposed around the photosensitive drum 17 and upstream of the charging unit in the rotational direction 220 and downstream of the cleaning unit in the rotational direction 220. . The second static elimination device 180 is disposed around the photosensitive drum 17 and upstream of the transfer unit in the rotation direction 220 and downstream of the development unit in the rotation direction 220.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and the embodiments can be obtained by appropriately combining the respective technical means disclosed in the above-described embodiments. The form is also included in the technical scope of the present invention.

  The static eliminator of the present invention is suitable for an electrophotographic image forming apparatus.

1 is a front view illustrating an internal configuration of an image forming apparatus according to an exemplary embodiment. FIG. 2 is a perspective view showing a photosensitive drum and a first charge removal device provided in the image forming apparatus of FIG. 1. FIG. 3 is a cross-sectional view showing the photosensitive drum and the first static elimination device of FIG. 2. It is sectional drawing which showed the static elimination apparatus of the same structure as the 1st static elimination apparatus of FIG. (A) is sectional drawing which showed the direction adjustment mechanism with which a 1st static elimination apparatus is equipped, (b) is the perspective view which showed the said direction adjustment mechanism. (A) is the figure which showed the direction adjustment mechanism different from the direction adjustment mechanism of FIG. 5, (b) is the figure which showed the state which rotated the eccentric cam half from the state shown by (a). is there. It is the figure which showed the light beam radiate | emitted from LED accommodated in a storage case, (a) shows the light beam which advances in the direction inclined from the axial direction of the photoconductive drum, (b) is the axial direction of a photoconductive drum. Shows a light beam traveling in parallel with.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Image forming apparatus 17 Photosensitive drum 80 1st static elimination apparatus 110 Light source unit (light source device)
111 LED (light emitting element)
112 Storage case (holding member)
120 Light Guide Plate 121 Incident Surface 122 Light Emitting Surface 123 Reflecting Surface 130 Direction Adjustment Mechanism 130a Direction Adjustment Mechanism 131 First Shaft (Shaft)
132 Second shaft 133 First bearing (bearing)
134 Second bearing 135 Adjustment knob 136 Fastening screw (switching member)
140 Elastic member 145 Eccentric cam 180 Second static elimination device 220 Direction of rotation

Claims (6)

In the static eliminator that removes charges from the photosensitive drum by irradiating light to the photosensitive drum provided in the electrophotographic image forming apparatus,
A light guide plate having an incident surface and irradiating light to the photosensitive drum by emitting light based on a light beam incident from the incident surface;
A light source device that emits a light beam toward the incident surface;
And a direction adjusting mechanism for adjusting a traveling direction of a light beam emitted from the light source device. The light source device includes a light emitting element that emits the light beam, and a holding member that holds the light emitting element while being fixed,
The static eliminator according to claim 1, wherein the direction adjustment mechanism is a rotation mechanism that rotates the holding member so that the traveling direction is adjusted. The rotation mechanism is
One end is fixed to the outer surface of the holding member, and a shaft serving as a rotating shaft in the rotating mechanism;
A bearing that supports the shaft;
3. A switching member that switches between a fixed state in which the shaft is fixed to the bearing and a rotatable state in which the shaft is supported by the bearing so that the shaft can rotate. The static eliminator described in 1. The rotation mechanism is
One end is fixed to the outer surface of the holding member, and a shaft serving as a rotating shaft in the rotating mechanism;
A bearing that supports the shaft;
An eccentric cam having an axis parallel to the rotation axis as a center of rotation;
3. The elastic member according to claim 2, further comprising an elastic member inserted between the holding member and a wall surface of the image forming apparatus and abutting the holding member on a circumferential surface of the eccentric cam by an elastic force. The static elimination apparatus of description. A photosensitive drum, and a charging unit for charging the photosensitive drum in order from the upstream side in the rotation direction of the photosensitive drum around the photosensitive drum; and exposing the charged photosensitive drum to form a latent image. An exposure portion to be formed, a developing portion for developing the latent image, a transfer portion for transferring an image developed by the developing portion to a sheet, and toner remaining on the peripheral surface of the photosensitive drum after the transfer. In an electrophotographic image forming apparatus in which a cleaning unit to be removed is set,
5. The static eliminator according to claim 1, around the photosensitive drum, upstream of the charging unit in the rotation direction and downstream of the cleaning unit in the rotation direction. 6. An image forming apparatus comprising: A photosensitive drum, and a charging unit for charging the photosensitive drum in order from the upstream side in the rotation direction of the photosensitive drum around the photosensitive drum; and exposing the charged photosensitive drum to form a latent image. An exposure portion to be formed, a developing portion for developing the latent image, a transfer portion for transferring an image developed by the developing portion to a sheet, and toner remaining on the peripheral surface of the photosensitive drum after the transfer. In an electrophotographic image forming apparatus in which a cleaning unit to be removed is set,
5. The static eliminator according to claim 1, around the photosensitive drum, on an upstream side in the rotation direction with respect to the transfer unit and on a downstream side in the rotation direction with respect to the developing unit. An image forming apparatus comprising:

Images