JP2005127172A - Blowing device and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blowing device capable of uniformly blowing air to an object. <P>SOLUTION: This blowing device blowing air to the object comprises a blowing means and a flow passage guiding an air stream produced by the blowing means from an inlet to an outlet. The blowing means is an axial-flow fan, and the axial-flow fan is disposed at the inlet of the flow passage on the end part side of the axial-flow fan in the direction orthogonal to the rotating direction of the axal-flow fan, the outlet of the flow passage is opened in the direction orthogonal to the rotating axis direction of the axial-flow fan, and a turning wall tilted at an angle relative to the rotating shaft of the axial-flow fan is installed on the exhaust side of the axial-flow fan. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus used for an electrophotographic printer, a copying machine, and the like, and an air blowing device for sending air to a blowing object such as a corona charger in the image forming apparatus.

  Conventionally, for example, in an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus, an electrophotographic photosensitive member / an electrostatic recording dielectric body such as an electrophotographic photosensitive member (charged body) is uniformly charged to a required polarity and potential. A corona charger (corona discharger) is often used as a charging device for processing (including charge removal processing).

  A corona charger is a non-contact type charging device. For example, a corona charger includes a discharge electrode such as a wire electrode and a shield electrode surrounding the discharge electrode, and a discharge opening is opposed to an image carrier as a charged body. The image carrier surface is charged to a predetermined level by exposing the image carrier surface to a discharge current (corona shower) generated by applying a high voltage to the discharge electrode and the shield electrode.

  The corona charger, which has been the mainstream of the conventional charging method, applies a high voltage of about 5 to 10 kV to a metal wire of about φ50 to 100 μm, ionizes the atmosphere, and imparts charge to the opposite object. In the process, the wire itself also absorbs dirt, and periodic cleaning and replacement are necessary. In addition, a large amount of ozone is generated with corona discharge.

  Electrophotographic photosensitive members used in recent years have a high surface hardness in order to increase the number of printing durability, and are to be charged under the influence of corona products derived from ozone generated from a charger by repeated use. The surface of the photoconductor becomes sensitive to humidity. For this reason, the photosensitive member easily adsorbs moisture, which causes a lateral flow of charges on the surface of the photosensitive member, and has a defect of causing image quality deterioration called image flow.

  Therefore, at present, there is a device that discharges ozone and corona products in the corona charger by using an air blowing means such as a fan and a duct 101 from outside the machine to guide the air flow into the corona charger (for example, patents). Reference 1).

  In Patent Document 1, fins 107 are formed in the duct 101 for blowing air. As a result, the wind entering from the duct inlet 105 can be guided substantially uniformly toward the duct outlet 106. By uniformly applying the wind to the photoconductor in this way, ozone and corona products can be discharged uniformly throughout the longitudinal direction in the corona charger. Has been eliminated.

  Here, as shown in FIG. 9, since the blowing means such as a fan is normally blown from the front side of the machine, the air current is uniformly guided in the longitudinal direction of the corona charger to the duct 101 that guides the air current to the corona charger. The adjustment fins are arranged for rectification.

Japanese Patent Laid-Open No. 8-21703

  In recent years, colorization and speeding-up of copying machines are rapidly progressing. Therefore, due to the increase in the number of toner colors and the increase in the amount of toner used, it is essential to increase the size and size of toner bottles for storing toner. Here, in order to avoid an increase in the size of the entire machine, there are many cases in which the toner bottle is not arranged inside the machine but is arranged using, for example, the space below the operation panel on the front side of the machine ( (Refer to the broken lines in FIGS.

  Then, it becomes difficult to arrange the fan for blowing the corona charger on the front side of the machine. Even if it is arranged, the air path by the duct from the fan to the corona charger becomes long and complicated, and the efficiency becomes poor. As a result, the fan is increased in size and speeded up in order to increase the air volume, and there is a risk of adversely affecting space, noise, power consumption, cost, and the like.

  Further, in order to blow air uniformly in the longitudinal direction of the corona charger, fins are arranged in the duct and rectification is performed, but adjustment of the fin shape is not easy. In addition, it is not analog homogeneity such as uniform in the entire longitudinal direction, but it is only digital homogeneity in which the vicinity of the fin is uniform but weakens as it moves away from the fin.

  Then, the objective of this invention is providing the air blower which can air uniformly with respect to a target object.

  A typical configuration according to the present invention for achieving the above object includes an air blowing means and a flow path for guiding an air flow generated by the air blowing means from an inlet to an outlet, and blows air to an air blowing object. In the apparatus, the air blowing means is an axial fan, and the axial fan is disposed at an end of the flow path inlet in a direction orthogonal to the rotational axis direction of the axial fan, and the flow path outlet is It has a turning wall that opens in a direction orthogonal to the rotational axis direction of the axial fan, and has a turning wall that is inclined at an angle with respect to the rotational axis of the axial fan on the exhaust side of the axial fan.

  Thus, since it was set as the structure which has a turning wall, the air ventilated from the axial fan is uniformly sent to an opening of a flow-path exit by a turning wall in a longitudinal direction. For this reason, it can blow uniformly with respect to a target object.

  Since the present invention has the above-described configuration and operation, it is possible to uniformly blow air to the object.

  An embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. 1 and 2 are overall configuration diagrams of the image forming apparatus, FIG. 3 is an overall view of the duct and the fan, FIG. 4 is a cross-sectional view of the duct and the fan, and FIGS. FIG. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.

  The image forming apparatus shown in FIG. 1 forms an electrostatic latent image on an image carrier made of a photosensitive member, develops the latent image and transfers it to a sheet, thereby forming a full color image. An image forming apparatus.

(Configuration of image forming apparatus)
As shown in FIG. 1, an image reading unit for reading image information from a document is provided on the upper portion of the image forming apparatus main body. The image reading unit includes an original platen glass 30, an exposure lamp 31 for exposing the original S on the original platen glass 30, and mirrors 12 a, 12 b, and 12 c that reflect light from the exposure lamp 31 subjected to scanning exposure. And a lens 13 for condensing the light, and a full color sensor 14 for detecting the light collected by the lens 13.

  The image forming unit is configured around a photosensitive drum 15 as an image carrier. Around the photosensitive drum 15, there are a pre-exposure lamp 16, a corona charger 17, a laser exposure optical system 18 (rotating polygon mirror 18 a, lens 18 b, mirror 18 c, etc.) as exposure means, a potential sensor 19, a cleaning device 24, A fixed black developing device 21K, three rotatable color developing devices 20Y, 20M and 20C, and an intermediate transfer member 9 are arranged. The three rotating developing devices 20Y, 20M, and 20C are detachably held by a developing rotary 23 that rotates about a rotating shaft 22, respectively. The developing devices 20Y, 20M, and 20C use non-magnetic toner, and the developing device 21K uses magnetic toner.

  A fixing device including a fixing roller 26 and a pressure roller 27 is disposed downstream of the intermediate transfer member 9 in the conveyance direction of the transfer material 11.

(Operation of image forming apparatus)
With such a configuration, the document S placed on the document table glass 30 is exposed and scanned by the exposure lamp 31. The reflected light image from the original reaches the lens 13 by the mirrors 12a, 12b, and 12c and is condensed, and is converted into a color color separation image signal by the full color sensor. The color-separated image signal is processed by a video processing unit through an amplifying circuit (not shown) and sent to an image forming unit to be described later.

  When an image formation start signal is input to the image forming unit, first, the photosensitive drum 15 is rotationally driven in the direction of arrow A by a driving unit (not shown).

  In the laser exposure optical system 18, the image signal from the image reading unit is converted into an optical signal by a laser output unit (not shown). The converted laser beam is reflected by the rotary polygon mirror 18a and projected onto the cylindrical surface of the photosensitive drum 15 through the lens 18b and the mirror 18c. At the time of image formation, the photosensitive drum 15 is rotated in the direction of the arrow A, and the photosensitive drum 15 after being neutralized by the pre-exposure lamp 16 is uniformly charged by the corona charger 17, and an optical image is formed for each separated color. Irradiation forms an electrostatic latent image.

  When forming an image, that is, developing an electrostatic latent image, each developing device is rotated about the rotation shaft 22 while being held by the developing rotary 23. When the predetermined developing device stops at a position facing the photoconductive drum 15 and the developing sleeve is positioned so as to face the photoconductive drum 15 with a minute interval, the electrostatic latent image on the photoconductive drum 15 is dealt with. To form a visible image.

  At the time of color image formation, the development rotary 23 rotates every rotation of the intermediate transfer member 9, and the development process is performed in the order of the magenta developing unit 20M, the yellow developing unit 20Y, the cyan developing unit 20C, and then the black developing unit 21K.

  The intermediate transfer member 9 undergoes multiple transfers of the visible image on the photosensitive drum 15 visualized by each developing device during the color image forming operation four times (each image of four colors of M, Y, C, and K). . Therefore, it rotates in the direction of arrow B in synchronization with the outer peripheral speed of the photosensitive drum 15. In addition, the intermediate transfer body 9 that has undergone multiple transfer squeezes and conveys the transfer material 11 with the transfer roller 10 to which a voltage is applied, thereby simultaneously multiplexing the color toner images on the intermediate transfer body 9 onto the transfer material 11. The image is transferred and sent to the fixing device which is the next process.

  The transfer material 11 holding the toner image is conveyed by the fixing roller 26 and the pressure roller 27 and is applied with heat and pressure, whereby the toner is fixed to the transfer material 11. The toner that has not been transferred onto the transfer material 11 is removed from the photosensitive drum 15 by the cleaning blade 28 in the cleaning device 24. The potential on the photosensitive drum 15 is made uniform by the pre-exposure lamp 16 and then charged again by the corona charger 17 to be used for the next image formation.

  A predetermined amount of toner is automatically replenished from the black toner bottle 8 each time the toner of the black developing device 21K is consumed for continuing image formation. Similarly, when the toner of the magenta developing device 20M, the yellow developing device 20Y, and the cyan developing device 20C is consumed, a predetermined amount is linked to the rotation operation of the developing rotary 23 from a toner bottle (not shown) arranged in the developing rotary 23. Toner is automatically replenished.

  During the image forming operation, a large amount of ozone is generated from the corona charger 17. As described above, when the corona product is derived from ozone, the photosensitive drum 15 is adversely affected. For this reason, in the present invention, fresh air is taken in from the axial fan 2 and is blown to the corona charger 17 through the duct 1. This prevents the derivation of corona products from ozone. At the same time, foreign matter such as toner is prevented from adhering to the charged wire.

(Relationship between duct and axial fan)
The configuration of the duct 1 and the axial fan 2 shown in FIG. 1 will be described in detail with reference to FIGS.

  In the image forming apparatus, fresh air is blown into the corona charger 17 in order to remove ozone. Here, when blowing fresh air to the corona charger 17, it is necessary to uniformly blow air over the entire longitudinal direction. By uniformly blowing the air in the entire longitudinal direction, it is possible to prevent the occurrence of longitudinal unevenness of ozone concentration and longitudinal unevenness of the charged wire stain, and the longitudinal unevenness of the image can be prevented.

  An axial fan 2 is disposed at the air inlet 5 of the duct 1 to suck fresh air from the outside of the apparatus. Immediately after the intake port 5, a turning wall 3 having an angle with the rotation axis direction of the axial fan 2 is arranged to diffuse the sucked air downstream.

  As shown in FIGS. 3 and 4, the shape of the duct 1 is configured to spread toward the end in order to blow fresh air uniformly over the entire longitudinal direction. The exhaust port 6 of the duct 1 opens in the longitudinal direction in accordance with the opening of the corona charger 17. In the vicinity of the exhaust port 6 of the duct 1, distribution fins 4 that distribute the air flow are arranged.

(Angle of turning wall 3)
In this embodiment, good results were obtained by setting the angle of the deflecting wall 3 to about 55 ° compared to the axis of the axial fan 2. This angle is adjusted by the size and output of the axial flow fan 2 and the opening balance of the intake port 5 and the exhaust port 6 of the duct 1.

  The output of the axial fan 2 is variable, 24V when a large amount of ozone is generated, such as during a copy operation, etc. Ozone does not occur immediately after the end of the copy operation, but 12V when you want to exhale the in-machine ozone, then stop By doing so, power saving and noise measures are taken.

(Relationship with blade, turning wall 3, wind direction)
Next, the relationship between the rotation direction of the axial fan 2, the winding direction of the blades (not shown) of the axial fan 2, the direction change wall 3, and the wind direction will be described with reference to FIGS.

  5 and 6 show a case where the axial fan 2 rotates counterclockwise and the blades are clockwise when viewed from the suction side. When the turning wall 3 has a negative inclination with respect to the rotation axis of the axial fan 2 as seen from the front of the apparatus as shown in FIG. 5, wind is generated on the back side of the apparatus as shown by the arrow in the figure. When the turning wall 3 has a positive inclination with respect to the rotational axis of the axial fan 2 when viewed from the front of the apparatus as shown in FIG. 6, wind is generated on the front side of the apparatus as indicated by the arrows in the figure.

  7 and 8 show the case where the axial fan 2 is rotated clockwise and the blades are counterclockwise when viewed from the suction side. When the turning wall 3 has a negative inclination with respect to the rotational axis of the axial fan 2 when viewed from the front of the apparatus as shown in FIG. 7, wind is generated on the front side of the apparatus as indicated by the arrows in the figure. When the turning wall 3 has a positive inclination with respect to the rotation axis of the axial fan 2 as seen from the front of the apparatus as shown in FIG.

  By utilizing the characteristics of the above axial flow fan, the system shown in FIGS. 5 and 8 is arranged in front of the apparatus, and the systems shown in FIGS. . This embodiment is applicable to the case shown in FIG.

The image forming apparatus shown in FIG. 2 forms an electrostatic latent image on an image carrier made of a photoconductor, and develops the latent image and transfers it to a sheet to form a full color image. Device. In this example,
Since the operation is the same as that of the first embodiment, the description thereof is omitted.

  In the copying machine, there is a fixing device for fixing the toner image on the recording material. The fixing device becomes high temperature during the image forming operation and raises the temperature inside the apparatus. Even during standby, a certain temperature is maintained to make the next operation smooth, and the surrounding units are warmed. In order to suppress such a temperature rise, an air flow is configured in the apparatus. However, a unit in which toner exists has a low limit temperature and may have a dedicated air flow. As an example, an air flow with respect to the cleaning device 24 is given.

  The cleaning device 24 scrapes off the residual toner on the photosensitive drum 15 and conveys it to the outside of the apparatus, so that a lot of waste toner exists inside. Therefore, it is necessary to keep the temperature within 45 ° C. Although the temperature is low during the single-sided copy operation, the recording material once passed through the fixing device passes under the heat while the double-sided copy operation is in progress, so the temperature gradually rises.

  Therefore, as shown in FIG. 2, the duct 1a and the axial fan 2a are arranged toward the cleaning device 24, and fresh air from outside is applied to the entire longitudinal direction of the cleaning device 24 to suppress the temperature rise. .

  The output of the axial fan 2a is variable, 24V when the temperature rises rapidly during double-sided copy operation, 12V when you want to cool the remaining heat immediately after the end of the copy operation, etc. Power saving and noise by stopping during standby Measures are being taken.

  Further, the present invention is not limited to this, and an air flow may be formed for the developing devices 20Y, 20M, 20C, and 21K.

  The present invention relates to an image forming apparatus used for an electrophotographic printer, a copying machine, and the like, and can be used particularly for an apparatus including an object that receives air blown by a blowing means such as a corona charger.

1 is an overall configuration diagram of an image forming apparatus (Example 1). FIG. 2 is an overall schematic diagram of an image forming apparatus (Example 2). Overall view of duct and fan. Sectional drawing of a duct and a fan. Explanatory drawing of a duct, a fan, and a wind direction. Explanatory drawing of a duct, a fan, and a wind direction. Explanatory drawing of a duct, a fan, and a wind direction. Explanatory drawing of a duct, a fan, and a wind direction. Explanatory drawing of a duct, a fan, and a wind direction (conventional example).

Explanation of symbols

S ... manuscript,
DESCRIPTION OF SYMBOLS 1 ... Duct, 1a ... Duct, 2 ... Axial fan, 2a ... Axial fan, 3 ... Turning wall,
4 ... Sorting fins, 5 ... Intake port, 6 ... Exhaust port, 8 ... Black toner bottle,
9 ... Intermediate transfer member, 10 ... Transfer roller, 11 ... Transfer material,
12a ... mirror, 12b ... mirror, 12c ... mirror,
13 ... Lens, 14 ... Full color sensor, 15 ... Photosensitive drum,
16 ... Pre-exposure lamp, 17 ... Corona charger,
18 ... laser exposure optical system, 18a ... rotating polygon mirror, 18b ... lens,
18c ... mirror, 19 ... potential sensor,
20C: Cyan developing unit, 20M: Magenta developing unit, 20Y: Yellow developing unit,
21K: Black developer,
22 ... Rotating shaft, 23 ... Development rotary, 24 ... Cleaning device,
26 ... fixing roller, 27 ... pressure roller, 28 ... cleaning blade,
30 ... manuscript glass, 31 ... exposure lamp

Claims (8)

In a blower device that has a blowing means and a flow path that guides an airflow generated by the blowing means from an inlet to an outlet, and blows air to a blowing object.
The air blowing means is an axial fan,
The axial fan is disposed at the end of the flow path inlet in the direction orthogonal to the rotational axis direction of the axial fan,
The flow path outlet opens in a direction orthogonal to the rotational axis direction of the axial fan,
An air blower characterized by having a turning wall inclined at an angle with respect to a rotation axis of the axial fan on an exhaust side of the axial fan. In an image forming apparatus having an image carrier and a blower for blowing air to the image carrier,
The blower device has a blower means and a flow path for guiding the airflow generated by the blower means from the inlet to the outlet,
The air blowing means is an axial fan,
The axial fan is disposed at the end of the flow path inlet in the direction orthogonal to the rotational axis direction of the axial fan,
The flow path outlet opens perpendicular to the rotational axis direction of the axial fan,
An image forming apparatus comprising a turning wall inclined at an angle with respect to a rotation axis of the axial fan on an exhaust side of the axial fan. When the shape of the blades of the axial fan is right-handed and the rotational direction of the axial fan is counterclockwise,
When the axial flow fan has a negative inclination with respect to the rotational axis of the axial fan as viewed from a visual line direction parallel to the rotational axis of the image carrier, the axial flow fan is in front of the visual line direction. Arranged at the end position of the image carrier on the side,
3. The image forming apparatus according to claim 2, wherein when the deflecting wall has a positive inclination, the image forming apparatus is disposed at an end position of the image carrier on the back side in the line-of-sight direction. When the shape of the blades of the axial fan is left-handed and the rotational direction of the axial fan is clockwise,
When the axial wall has a negative inclination with respect to the rotational axis of the axial fan when viewed from a visual line direction parallel to the rotational axis of the image carrier, the axial flow fan is Arranged at the end position of the image carrier on the side,
3. The image forming apparatus according to claim 2, wherein when the deflecting wall has a positive inclination, the deflecting wall is disposed at an end position of the image carrier on the near side in the line-of-sight direction.   The image forming apparatus according to claim 2, wherein a charger is disposed at a flow path outlet of the blower.   The image forming apparatus according to claim 2, wherein a cleaning unit or a developing unit is disposed at the outlet of the flow path.   The image forming apparatus according to claim 2, wherein the flow path outlet has one or a plurality of sorting fins for distributing the air flow in the longitudinal direction of the image forming apparatus.   The image forming apparatus according to claim 2, wherein the axial fan has a variable power output as necessary.

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