JP5618177B2 - Image forming apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming apparatus including the image forming apparatus.

  As a conventional image forming apparatus, an image forming apparatus employing a direct recording type image forming method called toner jet, direct toning, toner projection or the like (hereinafter referred to as a direct recording type image forming apparatus) is known. (Patent Document 1 etc.). In this type of image forming apparatus, a latent image formed on a photoconductor is developed with an image forming agent such as toner as in an electrophotographic process, and the developed image is transferred from the photoconductor to a recording paper or transfer body. The image is not directly transferred, but the flying image forming agent is attached to the recording paper or transfer body to directly form the image on the recording paper or transfer body.

  FIG. 9 is a configuration diagram illustrating an example of a main configuration of a conventional direct recording type image forming apparatus. In FIG. 9, a toner carrying roller 501 is arranged so that its axis extends in the left-right direction in the drawing, and carries charged toner T on its surface while being driven to rotate by a driving means (not shown). Under this toner carrying roller 501, a flexible printed circuit board (hereinafter referred to as FPC) 503 is disposed as a hole forming member for forming a plurality of holes 502. The toner carried on the surface of the toner carrying roller 501 is transported to a position facing the FPC 503 after the amount of toner is regulated by a doctor blade (not shown) that contacts the surface of the toner carrying roller 501. The FPC 503 includes a plurality of ring-shaped flying electrodes 504 formed on the side facing the toner carrying roller 501 so as to surround each hole 502.

  A counter electrode 506 that faces the toner carrying roller 501 is disposed below the FPC 503 with the FPC 50 interposed therebetween. Further, the recording paper 507 is conveyed on the counter electrode 506 by a conveying means. In FIG. 9, only one hole 502 and one flying electrode 504 are shown for convenience, but a plurality of these combinations are actually formed in the FPC 503. Specifically, for example, in the FPC 503 for 600 [dpi], 4960 combinations of these are formed.

  When a flying voltage is applied to the flying electrode 504, the toner is caused to fly from the toner carrying roller 501 to the toner T at a position facing the flying electrode 504 on the toner carrying roller 501 or the toner T in the vicinity thereof. An electric field having a predetermined strength acts. Due to the action of the electric field, the electrostatic force applied to the toner T exceeds the adhesive force between the toner T and the toner carrying roller 501, and the aggregate of the toner T selectively flies from the toner carrying roller 501 in the form of dots and has holes. Enter 502. Then, it continues to fly by being attracted by an electric field formed between the flying electrode 504 and the counter electrode 506 to which a higher voltage is applied, and passes through the hole 502 and adheres to the surface of the recording paper 507. And become a dot image.

  In the direct recording method, in order to obtain a high-quality image with good dot image density and resolution, it is necessary to set and maintain the toner supply gap, which is the distance between the toner carrying roller 501 and the FPC 503, with high accuracy.

  In the image forming apparatus used in the direct recording type image forming apparatus, the applicant of the present application has applied the Japanese Patent Application No. 2008-273508 so that the toner supply gap, which is the distance between the toner carrying roller and the hole forming member, can be maintained at a predetermined distance. The following imaging device was proposed in the issue (hereinafter referred to as the prior application).

  In other words, the image forming apparatus described in the prior application includes a housing that stores toner, a toner carrying roller that is pivotally supported by the housing and is exposed to the outside, and a toner amount on the toner carrying roller. A toner regulating means for regulating toner, a sheet-like hole forming member which is formed with a plurality of holes and is opposed to the toner carrying roller at a predetermined interval, and a plurality of holes provided in the hole forming member corresponding to each of the plurality of holes And a flying electrode. In addition, the hole forming member is provided on the casing so as to cover the toner carrying roller, and the hole forming member is attached to the toner carrying roller shaft at its side wall formed with openings at least at positions opposed to the plurality of holes formed in the hole forming member. And positioning means for positioning the hole with respect to the toner carrying roller so that the relative position between the hole of the hole forming member and the toner carrying roller is in a predetermined positional relationship. Then, based on the image information, the toner selectively ejected from the toner carrying roller by the flying electric field formed by the flying electrode is attached to the recording member through the hole of the hole forming member to form an image.

  In the image forming apparatus described in the prior application, the positioning means holds the hole forming member over the toner carrying roller axial direction on the side wall, so that a bend or the like that causes the interval to vary in the toner carrying roller axial direction is formed in the hole. It can suppress producing in a member. Therefore, the interval between the toner carrying roller and the hole forming member is prevented from varying in the axial direction of the toner carrying roller, and can be maintained at the predetermined interval.

  However, in the image forming apparatus described in the prior application, there is a problem that the cost increases because the number of parts increases as the positioning means is provided.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus capable of setting and maintaining a predetermined interval between the agent carrier and the hole forming member while reducing costs. It is another object of the present invention to provide an image forming apparatus including the image forming apparatus.

In order to achieve the above object, the invention according to claim 1 is an image forming apparatus comprising: a housing that stores an image forming agent; and an opening that is pivotally supported by the housing and formed on a side surface of the housing. An agent carrier that faces the outside and carries an image forming agent accommodated in the housing, and a sheet-like member formed with a plurality of holes and facing the agent carrier with a predetermined interval therebetween A plurality of hole forming members and a plurality of electric fields that are provided in the hole forming members in correspondence with the plurality of holes, and that form an electric field that selectively causes the image forming agent to fly from the agent carrier toward the holes. The flying electrode and the housing are separate from each other , provided on the side surface of the housing where the opening is formed so as to cover the agent carrier, and at least on the wall portion facing the agent carrier. An opening is formed at a location facing the plurality of holes formed in the hole forming member, and the agent carrier on the wall portion The hole forming member is held in the axial direction of the agent carrier by the wall surface opposite to the opposite side, and the relative position between the agent carrier and the hole forming member is set to a predetermined positional relationship with respect to the agent carrier. and positioning means for positioning the porogenic member, Bei give a, a part of the wall facing the said agent carrier wall of said positioning means, said opening formed in the wall portion the edge facing the dosage carrying body carrying member rotating direction upstream side of and in contact with the surface of the carrier, and the spacing interval is given between the agent carrier and the hole forming member The hole forming member is positioned with respect to the agent carrier, and the edge of the positioning means is also used as an agent regulating unit that regulates the amount of the agent on the agent carrier. To do.
The invention according to claim 2 is the image forming apparatus according to claim 1, further comprising a holding member for detachably holding the casing, and the positioning means when the casing is mounted in the holding member. An opening is formed in the holding member so that the wall portion faces the outside of the holding member, and the hole forming member is provided in the holding member so as to cover the opening of the holding member, and the opening is formed in the holding member. It is configured that the hole forming member is positioned with respect to the agent carrier by the positioning means by mounting a housing and bringing the positioning means into contact with the hole forming member through the opening of the holding member. It is what.
According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the hole forming member is made of a flexible material, and has tension applying means that is provided on the holding member and applies tension to the hole forming member. It is characterized by.
According to a fourth aspect of the present invention, there is provided a housing for storing an image forming agent, and an image forming agent that is pivotally supported by the housing and faces the outside of the housing through an opening formed in the housing. And a sheet-like hole forming member formed so as to be opposed to the agent carrier at a predetermined interval, and a plurality of holes, and a plurality of holes formed in the hole. A plurality of flying electrodes for forming an electric field that is provided in the hole forming member and selectively causes the image forming agent to fly toward the hole from the agent carrier, and the agent carrier and the hole formation. An imaging means comprising positioning means for positioning the hole forming member with respect to the agent carrier so that the relative position to the member is in a predetermined positional relationship; and the agent carrier through the hole forming member Arranged to attract the image forming agent flying from the agent carrier. A counter electrode for forming a field, and based on image information, the image forming agent that has been selectively ejected from the agent carrier by forming the flying electric field is transferred to the counter electrode side through the hole. Then, in the image forming apparatus for forming an image by adhering to a recording member, the image forming apparatus according to claim 1, 2 or 3 is used as the image forming means.

In the present invention, the positioning means holds the hole forming member over the toner carrier axis direction on the wall surface of the wall opposite to the side facing the agent carrier, so that the interval varies in the toner carrier axis direction. Can be prevented from occurring in the hole forming member. Therefore, the interval between the toner carrier and the hole forming member can be prevented from varying in the axial direction of the toner carrier, and can be maintained at the predetermined interval.
Further, a part of the wall surface of the positioning means facing the agent carrier is brought into contact with or close to the surface of the agent carrier to regulate the amount of the agent on the agent carrier, and the positioning means is regulated by the agent. Also used as a means. Thereby, the number of parts can be reduced as compared with the case where the agent regulating means is provided separately, and the cost can be reduced accordingly.

  As mentioned above, according to this invention, the outstanding effect that the space | interval of an agent carrier and a hole formation member can be set and maintained to a predetermined | prescribed space | interval can be acquired, aiming at cost reduction.

The schematic diagram which shows the state which mounted | wore the image forming unit to the unit holder. 1 is a schematic configuration diagram illustrating a main part of an image forming apparatus according to an embodiment. FIG. 3 is a schematic configuration diagram of a direct recording method. Explanatory drawing which shows an example of the control pulse applied to a control electrode. FIG. 3 is a schematic diagram illustrating an example of a toner control electrode substrate. The schematic diagram which shows the state which removed the image formation unit from the unit holder. The schematic diagram which shows an example of the holder which is a guide member. The schematic diagram which shows the other examples of a guide member. FIG. 10 is a configuration diagram illustrating an example of a main configuration of a conventional direct recording type image forming apparatus.

Hereinafter, embodiments of the present invention will be described.
FIG. 2 is a schematic side view showing a configuration of an image forming unit of a color image forming apparatus using the intermediate transfer belt 20 as a transfer medium. Color image formation in which a toner image is formed on the intermediate transfer belt 20 by the printer unit 12, and the toner image is sequentially superimposed on the intermediate transfer belt 20 for each color during one rotation of the intermediate transfer belt 20. Device. Since the toner images of the respective colors are directly superimposed on the intermediate transfer belt 20, the positional deviation can be reduced as compared with an electrophotographic color image forming apparatus using a photosensitive member and an intermediate transfer member.

  In the image forming unit, an intermediate transfer belt 20 as a toner image carrier is a drive roller 21, a tension roller 22, a transfer counter roller 23, an opposing roller 24 that is an electrode (counter electrode) on the intermediate transfer belt 20 side used for toner control, and the like. In the case of the present embodiment, it is arranged vertically and vertically.

  The intermediate transfer belt 20 is rotated counterclockwise in the figure by a motor (not shown) connected to the drive roller 21. On the left side of the extended surface of the intermediate transfer belt 20, four printer units 12 of different colors stored in the same configuration are stacked so as to be stacked at a constant interval along the moving direction of the intermediate transfer belt 20. Are placed sequentially.

  Each printer unit 12 is placed horizontally with respect to the main body of the apparatus, and is opposed to a corresponding opposing roller 24 of each color with the intermediate transfer belt 20 interposed therebetween, and a toner control electrode substrate (described later) of the printer unit 12 is opposed to the intermediate transfer belt 20. They are set apart by a predetermined interval (several hundreds [μm]) called a printing gap. The position is set as the printing position.

  In addition, a transfer roller 27 that forms a transfer portion with the transfer counter roller 23 with the intermediate transfer belt 20 interposed therebetween, or a reference signal for an image forming operation between the drive roller 21 and the transfer counter roller 23 inside the loop of the intermediate transfer belt 20. A mark sensor 25 and the like for generating the.

  On the lower side of the intermediate transfer belt 20, the transfer section is carried in such that the sheet conveyance direction is inclined with respect to the transfer section formed by the transfer roller 27 and the transfer counter roller 23 with the intermediate transfer belt 20 interposed therebetween. In addition, a paper feeding / conveying unit 30 including a paper feeding roller 28 and a registration roller pair 29 is arranged, and a fixing device 32 is arranged on the carry-out side of the transfer unit. The color image forming apparatus main body is provided with a rotating shaft 33, and the intermediate transfer belt 20, the transfer section, and the fixing device 32 with respect to the apparatus main body are left with the printer unit 12 and the paper feeding / conveying section 30 remaining in the apparatus main body. Etc. can be integrally separated.

  Each printer unit 12 stores toner of each color of yellow (Y), magenta (M), cyan (C), and black (Bk). The toner is transferred from each printer unit 12 onto the intermediate transfer belt 20. Each color toner image is formed on the intermediate transfer belt 20 so that the four color toner images are superimposed. The superimposed toner images are sent to the transfer unit by the rotation of the intermediate transfer belt 20.

  On the other hand, in synchronization with the above-described printing or image forming operation, the sheet conveying sequence is operated by the sheet feeding / conveying unit 30, the sheet is conveyed by the sheet feeding roller 28, the registration roller pair 29, and the like, and the intermediate transfer belt 20. Touch along the surface. Then, the toner image and the paper are combined at the transfer portion, and the four color toner images on the intermediate transfer belt 20 are collectively transferred onto the paper by applying a bias of the transfer roller 27. The transferred paper is peeled off from the intermediate transfer belt 20 by a static elimination needle or the like (not shown) and sent to the fixing device 32 to fix the toner image on the paper. The residual toner remaining on the intermediate transfer belt 20 after the transfer is cleaned by the cleaning blade 26, and the intermediate transfer belt 20 prepares for the next image formation.

  In the color image forming apparatus according to the present embodiment, four color toner images are superimposed on the intermediate transfer belt 20 by the printer unit 12 and the color image is output by one rotation of the intermediate transfer belt 20. A color image can be output at high speed, and the color image forming apparatus can be miniaturized.

  In the present embodiment, the printer unit 12 is mounted on the color image forming apparatus using the intermediate transfer belt 20, but the present invention is not limited to this. For example, a color image forming apparatus of a type that prints toner of each color on the paper directly from the printer unit 12 without using an intermediate transfer medium such as the intermediate transfer belt 20 may be used.

FIG. 3 is a schematic configuration diagram of a direct recording method adapted to the present invention.
In this embodiment, the toner carrying roller 1 that carries the toner T in a clouded state, the recording medium 3 to which the toner T is attached, and between the toner carrying roller 1 and the recording medium 3 are used. And a toner control electrode substrate 4 having a plurality of toner passage holes 41 arranged on the surface. In FIG. 3, only one toner passage hole 41 is shown for convenience, but a plurality of toner passage holes 41 are actually formed.

  The toner carrying roller 1 has a predetermined pitch formed along a direction (here, an axial direction) orthogonal to a direction in which the toner T is conveyed at a predetermined interval in a direction (here, circumferential direction) in which the toner T is conveyed to the front side. A pulse voltage (cloud pulse) having an average potential Vs having a different potential with time is applied from the power source 5 to each electrode 11 of the toner carrying roller 1. This constitutes a means for converting the toner T into a cloud.

  For example, a pulse voltage having a frequency of 0.5 [kHz] to 7 [kHz] is applied, and the distance between the electrodes 11 is set to a fine pitch, so that a strong electric field is formed between the electrodes 11. Therefore, the toner T flies vigorously from the surface of the electrode 11 at a potential repelling the charged polarity of the toner T, and the toner T that has flew is attracted to the electrode 11 to which the potential of the attracting polarity is applied, and a pulse is generated. By switching, the vertical flight according to the pulse frequency is repeated, and the toner T is in a cloud state. In the region where the frequency of the pulse is high, the toner T that has flew upward may change its pulse while flying, and may fly upward again before returning to the surface of the electrode 11.

  The toner control electrode substrate 4 is provided with a plurality of toner passage holes (openings) 41 through which the toner T can pass, and around the toner passage holes 41 on the toner supply side surface (surface on the toner carrying roller 1 side) of the toner control electrode substrate 4. Is provided with a control electrode 42 in a ring shape.

  For example, a control pulse voltage Vc as shown in FIG. 4 is applied from the control pulse generating means 6 to the control electrode 42 of the toner control electrode substrate 4. In this case, the voltage Vc-on is applied to the control electrode 42 when the toner T is allowed to pass through the toner passage hole 41 (ON state), and the control is performed when the toner T is not allowed to pass (OFF state). A voltage Vc-off is applied to the electrode 42. The control electrode 42 of the toner control electrode substrate 4 can be operated only around the toner passage hole 41, but the inner wall surface of the toner passage hole 41 or the inner wall surface of the toner passage hole 41 and the periphery of the toner carrying roller 1 side. It may be provided in both.

  On the recording medium 3 side, a counter as electrode means serving as a bias voltage applying means is applied to the back surface of the recording medium 3 to apply a bias voltage for adhering the toner T that has passed through the toner control electrode substrate 4 to the recording medium 3. A bias voltage Vp from a bias power source 8 is applied to deposit the toner T on which the electrode 31 is disposed and passed through the toner control electrode substrate 4 to the recording medium 3. The recording medium 3 may be an intermediate transfer belt 20 that forms an image once on the recording medium and then transfers the recording medium to paper, or recording paper. The bias voltage Vp is applied to the recording medium 3 by, for example, arranging the counter electrode 31 on the back side (the side opposite to the toner carrying roller 1) of the recording medium 3 and passing the recording medium 3 on the top surface of the counter electrode 31. Alternatively, in the case of the intermediate transfer belt 20, a configuration in which electrodes are embedded (a configuration in which an electrode on the recording medium means side is used as an internal electrode) or a counter electrode 31 (a counter roller 24 in FIG. 2) is provided on the back surface of the intermediate transfer belt 20. It can be set as the structure which arranged.

  An example of a cross-sectional composition of the toner control electrode substrate 4 is shown in FIG. The toner control electrode substrate 4 includes a plurality of toner passage holes 41 provided in an insulating base material 45 and ring-shaped control electrodes 42 provided around each of the plurality of toner passage holes 41.

  The insulating base 45 generally uses a flexible flexible substrate (FPC), but a material such as a glass substrate may be used. In this embodiment, FPC having a thickness of 25 [μm] is used as the base material 45.

  The diameter of the toner passage hole 41 is set to about 50 [μm] to 200 [μm] depending on the resolution of the apparatus. By arranging the toner passage holes 41 in a staggered arrangement as shown in FIG. 5, a high-resolution image can be formed.

  In the present embodiment, the control electrode 42 is a ring-shaped electrode having a width of 40 [μm] to 100 [μm]. The control electrode 42 provided in each of the plurality of toner passage holes 41 is connected to a power source via an IC chip (not shown), and is configured to be able to variably control the voltage.

  Further, as a result of experiments by the inventors of the present application, as a result, the interval d1 that is a toner supply gap between the toner carrying roller 1 and the toner control electrode substrate 4 is set to 50 [μm] to 300 [μm], and the toner control electrode substrate By setting the distance d2 between 4 and the recording medium 3 to about 500 [μm] to 1 [mm], good image formation could be obtained.

  In the image forming apparatus of the direct recording method configured as described above, by applying a pulse voltage of the average potential Vs to the electrode 11 of the toner carrying roller 1, the toner T flies on the toner carrying roller 1 and is clouded. The toner T is conveyed by rotation of the toner carrying roller 1 or conveyance by a traveling wave electric field. On the other hand, a bias voltage Vp is applied to the counter electrode 31 on the recording medium 3 side.

  In this state, when the toner T is allowed to pass through the toner passage hole 41 with respect to the control electrode 42 of the toner control electrode substrate 4 (ON state), the ON voltage Vc-on shown in FIG. When the toner T cannot pass through the toner passage hole 41 (OFF state), the OFF voltage Vc-off shown in FIG. 4 is applied.

  In this case, by setting the voltage for each of these electrodes 11, 31, 42 to a certain value, the toner control electrode substrate 4 is in a state where the toner T of the toner carrying roller 1 can pass toward the recording medium 3. In addition, an electric force line 10 passing through the toner passage hole 41 is formed between the recording medium 3 side and the toner control electrode substrate 4.

  As a result, the toner clouded on the toner carrying roller 1 rides on the electric field generated by the electric force lines 10 and passes through the toner passage hole 41 of the toner control electrode substrate 4 and lands on the recording medium 3. Therefore, a toner image can be formed directly on the recording medium 3 by ON / OFF control (open / close control) of each toner passage hole 41 of the toner control electrode substrate 4 according to the image.

  Next, an embodiment of the printer unit 12 of the present invention using the toner control electrode substrate 4 and the toner carrying roller 1 of the direct recording method will be described.

  FIG. 1 is a schematic configuration diagram of the printer unit 12 viewed from the side. The printer unit 12 is a unit holder having an image forming unit 13 that supports the toner carrying roller 1, and an upper holder portion 50a and a lower holder portion 50b that are fixed to the image forming apparatus main body and hold the image forming unit 13 in a detachable manner. 50, and the imaging unit 13 is a replaceable exchange unit.

  The image forming unit 13 contains a one-component developer made of nonmagnetic toner. Note that a two-component developer composed of a magnetic carrier and a nonmagnetic toner may be used.

  The image forming unit 13 includes an image forming unit case 13d in which a developer is stored, a roller-shaped toner carrying roller 1 that carries toner, and a supply roller that supplies the developer in the image forming unit case 13d to the toner carrying roller 1. 13a and two stirring screws 13b and 13c for stirring the developer in the image forming unit case 13d. The toner carrying roller 1, the supply roller 13a, the stirring screws 13b and 13c, etc. Provided in a case 13d.

  The image forming unit case 13d is configured such that the side on which the toner carrying roller 1 is supported (the right side surface in the figure) is open, and the toner carrying roller 1 is exposed to the outside of the image forming unit case 13d. A holder 14 is attached to the open side surface of the image forming unit case 13d where the toner carrying roller 1 is supported and exposed so as to cover the toner carrying roller 1 with screws. An opening is formed in the wall portion of the holder 14 facing the toner carrying roller 1.

  The toner carrying roller 1 is rotatably supported on the side plate of the image forming unit case 13d, and is connected to a motor (not shown) to be driven to rotate. Then, the two-component developer is conveyed to a position facing the toner carrying roller 1 by a supply roller 13a containing a permanent magnet, where a bias is applied to a part of the toner, and the toner is supplied to the toner carrying roller 1 by the bias potential. The toner is transferred from the roller 13a. Alternatively, the toner carrying roller 1 and the supply roller 13a are made to have different surface speeds, and the toner is transferred from the supply roller 13a to the toner carrying roller 1 using friction due to the difference in speed. The toner transferred to the toner carrying roller 1 becomes a cloud state by the method described above.

  Here, a part of the wall surface of the holder 14 facing the toner carrying roller 1 on the side facing the toner carrying roller 1, more specifically, on the upstream side of the rotation of the toner carrying roller in the opening formed in the wall portion. As shown in FIG. 2, an edge portion 14 a facing the toner carrying roller 1 is provided in contact with the surface of the toner carrying roller 1, and the amount of toner on the toner carrying roller 1 by the edge portion 14 a of the holder 14. Is regulated. That is, in the present embodiment, the holder 14 is also used as a toner amount regulating unit that regulates the toner amount on the toner carrying roller 1. As a result, the number of parts can be reduced as compared with the case where the toner amount regulating means is separately provided, and the cost can be reduced accordingly.

  The edge 14a of the holder 14 is pressed against the toner carrying roller 1 side with an optimal pressing pressure depending on the stiffness of the wall and the installation angle.

  In this embodiment, the thickness of at least the edge portion 14 a of the wall portion of the holder 14 corresponds to the toner supply gap to be set between the toner carrying roller 1 and the toner control electrode substrate 4. The thickness is set (the distance d1 shown in FIG. 2). As a result, the toner carrying roller 1 and the toner control electrode substrate 4 can be easily and accurately adjusted with the thickness of the wall portion of the holder 14 which is in contact with and sandwiched between the toner carrying roller 1 and the toner control electrode substrate 4. It is possible to make the toner supply gap between the predetermined intervals.

Due to the rotation of the toner carrying roller 1, the toner on the toner carrying roller 1 whose toner amount is regulated by the edge 14 a of the holder 14 and thinned is carried to a position facing the toner control electrode substrate 4. Then, by the above-described method, the clouded toner on the toner carrying roller 1 is placed on the electric field, passes through the toner passage hole 41 of the toner control electrode substrate 4 and is landed and printed on the recording medium 3 (not shown). .

  The toner that has not been used for printing on the toner carrying roller 1 returns to the supply roller 13 a again by the rotation of the toner carrying roller 1. Since the adhesion force of the toner in the cloud state to the surface of the toner carrying roller 1 is very low, the toner on the toner carrying roller 1 returned to the position facing the supply roller 13a without being printed is rotated by the supply roller 13a. It is easily scraped or leveled by the following developer. By repeating this, a substantially constant amount of toner is always carried on the toner carrying roller 1 in a cloud state.

  Further, although there is a possibility that the toner adheres to the edge portion 14a of the holder 14 due to use over time, the holder 14 can be easily replaced along with the replacement cycle of the supply unit.

  FIG. 6 shows a state in which the image forming unit 13 is detached from the unit holder 50. The image forming unit 13 is placed in the unit holder 50 in the direction of the arrow in the drawing, that is, the upper holder portion 50a and the lower holder portion of the unit holder 50. It is inserted into the hollow interior formed between the two parts 50b and brought into a mounted state as shown in FIG. Both ends of the hollow image forming unit in the insertion direction are open so as to communicate with the outside.

  The unit holder 50 is provided with a toner control electrode substrate 4 so as to cover the opening at the downstream end portion in the hollow image forming unit insertion direction. One end side of the toner control electrode substrate 4 is attached to the outer wall of the lower holder part. On the other hand, the other end side of the toner control electrode substrate 4 is connected to the other end of a tension applying member 55 made of a spring having one end supported by a support plate 56 attached to the outer wall of the upper holder portion 50a. The toner control electrode substrate 4 is held by the unit holder 50 in a state where tension is applied so that the toner control electrode substrate 4 is not pulled and loosened by the tension applying member 55 from the one end side to the other end side.

  When the image forming unit 13 is mounted in the unit holder 50, the toner control electrode substrate 4 and the wall surface 14b of the holder 14 come into contact with each other, and the toner control electrode substrate 4 is pressed against the image forming unit 13 through the holder 14. Become. In this way, as will be described later, the toner supply gap that is the distance between the toner carrying roller 1 and the toner control electrode substrate 4 by the holder 14 is managed.

  In addition, the toner control electrode substrate 4 can be held on the unit holder 50 while applying tension to the toner control electrode substrate 4 by the tension applying member 55 and suppressing the slackness of the toner control electrode substrate 4. And the toner control electrode substrate 4 can be maintained with higher accuracy.

  As described above, in this embodiment, in order to form and set a toner supply gap, which is an interval between the toner carrying roller 1 and the toner control electrode substrate 4, at a predetermined interval, the toner carrying roller 1 and the toner control electrode substrate 4 are set. Is disposed between the image forming unit 13 and the toner control electrode substrate 4.

  A method of directly attaching the toner control electrode substrate 4 to the image forming unit case 13d of the image forming unit 13 without using the holder 14 while being curved so as to cover the toner carrying roller 1, for example, is conceivable. Therefore, it is difficult to accurately set and maintain the toner supply gap over the entire area of the toner control electrode substrate 4. Further, there is a risk of resonance due to vibration from the drive system of the image forming apparatus main body, and there is a risk of gap fluctuations.

  In order to solve these problems, the toner control electrode substrate 4 is guided over the entire area at an accurate position so as to form a desired surface shape on the toner control electrode substrate 4 and between the toner carrying roller 1 and the toner control electrode substrate 4. It is necessary to position the toner control electrode substrate 4 with respect to the toner carrying roller 1 so that the toner supply gap becomes a predetermined interval.

  Therefore, in the present embodiment, the positioning is performed by guiding the toner control electrode substrate 4 so as to have a desired surface shape over almost the entire area of the toner control electrode substrate 4 except for the region of the toner passage holes 41 formed in the toner control electrode substrate 4. Have means. In this embodiment, as the positioning means, as shown in FIG. 7, an opening opened in the toner carrying roller rotation direction and the toner carrying roller axial direction by an amount corresponding to the area of the toner passage holes 41 opened in the toner control electrode substrate 4. The portion 14c is formed on the wall portion facing the toner carrying roller 1, and the toner control electrode substrate 4 excluding the toner passage hole 41 is disposed on the wall surface on the opposite side of the wall portion from the side facing the toner carrying roller 1. The image forming unit 13 is provided with a holder 14 that is held in contact with 14b. The positioning means includes a support plate 15a and a support plate 15b facing the toner carrying roller 1 as shown in FIG. 8, and a plurality of toners opened on the toner control electrode substrate 4 in the toner carrying roller rotating direction. The toner control electrode substrate 4 excluding the region of the toner passage hole 41 is spaced by an amount corresponding to the region of the passage hole 41, and the side opposite to the side of the support plate 15a and the support plate 15b facing the toner carrying roller 1 is opposite. A holder 15 that is held in contact with the wall surface 15c or the wall surface 15d may be used.

  If this holder 14 is used, almost the entire area of the toner control electrode substrate 4 excluding the area of the toner passage hole 41 is held in contact with the wall surface 14b by the wall portion of the holder 14, so that the toner control as described above is performed. The defect due to the low rigidity of the electrode substrate 4 is eliminated, and the toner carrying roller is free from bending or distortion that causes the toner supply gap to vary in the toner carrier axial direction near the central portion of the toner carrier axial direction of the toner control electrode substrate 4. 1, a desired surface shape can be formed and set on the toner control electrode substrate 4 at an accurate position.

  In addition, since the gap between the toner carrying roller 1 and the toner control electrode substrate 4 can be regulated only by inserting one holder 14 between the toner carrying roller 1 and the toner control electrode substrate 4, the toner due to stacking tolerances or the like. Variations in supply gap can be minimized.

As described above, according to the present embodiment , in the printer unit 12 that is an image forming apparatus, the image forming unit case 13d that is a housing that stores the toner that is the image forming agent, and the image forming unit case 13d that is pivotally supported. The toner carrying roller 1 that is an agent carrying body that carries the toner accommodated in the image forming unit case 13d that faces the outside of the image forming unit case 13d from the opening formed in the side surface of the unit case 13d, and the toner that is a plurality of holes The toner control electrode substrate 4 that is a sheet-like hole forming member that is formed so as to face the toner carrying roller 1 with a predetermined interval is formed, and corresponds to each of the plurality of toner passing holes 41. An electric field is formed on the toner control electrode substrate 4 so that the toner can selectively fly from the toner carrying roller 1 toward the toner passage hole 41. A control electrode 42 is a plurality of flight electrodes because, the image forming unit case 13d is separately disposed on the side the opening of the image forming unit case 13d so as to cover the toner carrying roller 1 is formed An opening 14c is formed in a wall portion facing the toner carrying roller 1 at a location facing at least a plurality of toner passage holes 41 formed in the toner control electrode substrate 4, and opposed to the toner carrying roller 1 on the wall portion. The toner control electrode substrate 4 is held in the toner carrier axis direction by the wall surface 14b opposite to the side, and the toner carrier roller 1 is set so that the relative position between the toner carrier roller 1 and the toner control electrode substrate 4 is in a predetermined positional relationship. It includes a holder 14 is a positioning means for positioning the toner control electrode substrate 4, a relative, to face the toner carrier roller 1 of the wall portion of the holder 14 A part of the side wall, the edge 14a facing the toner carrier roller 1 in the toner carrying roller rotating direction upstream side of the opening 14c formed in the wall portion, in contact with the surface of the toner carrying roller 1 The toner control substrate 4 is positioned with respect to the toner carrying roller 1 so that the distance between the toner carrying roller 1 and the toner control electrode substrate 4 is a predetermined interval, and the edge 14c of the holder 14 is held by the toner carrying This was also used as a toner amount regulating means which is an agent regulating means for regulating the amount of toner on the roller 1. As a result, the holder 14 holds the toner control electrode substrate 4 in the toner carrier axis direction on the wall surface 14b of the wall portion, so that the interval between the toner carrier roller 1 and the toner control electrode substrate 4 varies in the toner carrier axis direction. It is possible to prevent the toner control electrode substrate 4 from being bent. Therefore, the interval between the toner carrying roller 1 and the toner control electrode substrate 4 can be prevented from varying in the axial direction of the toner carrying body, and can be maintained at the predetermined interval. Further, since also serves as a holder 14 as a toner amount regulating means for regulating the amount of toner on the toner carrying roller 1 by the wall portion of the edge 14a which is provided by touch against the surface of the toner carrying roller 1, the toner amount The number of parts can be reduced as compared with the case where a regulating means is provided separately, and the cost can be reduced accordingly.
Further, according to the present embodiment, the image forming unit 13 including the image forming unit case 13d and the like has the unit holder 50 that is a holding member that is detachably held, and the image forming unit 13 is mounted in the unit holder 50. An opening is formed in the unit holder 50 so that the wall portion of the holder 14 faces the outside of the unit holder 50, and the toner control electrode substrate 4 is provided in the unit holder 50 so as to cover the opening of the unit holder 50. The image forming unit 13 is mounted in the unit holder 50, and the holder 14 is brought into contact with the toner control electrode substrate 4 through the opening of the unit holder 50, whereby the toner carrying roller 1 is positioned with respect to the toner carrying roller 1 by the holder 14. It was configured as follows. Thus, since the toner control electrode substrate 4 is provided in the unit holder 50, the toner control electrode substrate 4 is not replaced with the image forming unit 13 when the image forming unit 13 is replaced. . Therefore, it is possible to prevent the toner control electrode substrate 4 from being replaced integrally with the image forming unit 13 even though the toner control electrode substrate 4 has not reached the end of its life. Therefore, the cost can be reduced because the toner control electrode substrate 4 is not replaced more than necessary.
Further, according to the present embodiment, the toner control electrode substrate 4 is made of a flexible material, and includes the tension applying member 55 that is provided on the unit holder 50 and is a tension applying unit that applies tension to the toner control electrode substrate 4. The toner control electrode substrate 4 can be held on the unit holder 50 while suppressing the occurrence of slack in the toner control electrode substrate 4. Therefore, the interval between the toner carrying roller 1 and the toner control electrode substrate 4 can be maintained with higher accuracy.
Further, according to the present embodiment, the image forming unit case 13d that is a housing for storing the toner that is the image forming agent, and the opening that is pivotally supported by the image forming unit case 13d and formed in the image forming unit case 13d. A toner carrying roller 1 that faces the outside of the image unit case 13d and carries toner accommodated in the image forming unit case 13d, and a toner passage hole 41 that is a plurality of holes, are formed, and the toner carrying roller 1 is spaced at a predetermined interval. The toner control electrode substrate 4 that is a sheet-like hole forming member disposed so as to face the toner and the toner control electrode substrate 4 corresponding to each of the plurality of toner passage holes 41, and the toner carrying roller 1 to the toner A control electrode 42 which is a plurality of flying electrodes for forming an electric field to selectively fly toward the toner passage hole 41, and the toner carrying roller 1. An image forming means comprising a holder 14 which is a positioning means for positioning the toner control electrode substrate 4 with respect to the toner carrying roller 1 so that the relative position to the toner control electrode substrate 4 is in a predetermined positional relationship; and the toner control electrode substrate 4 And a counter electrode 31 for forming an electric field that attracts the toner flying from the toner carrying roller 1, and based on image information, the flying electric field is provided. The toner selectively ejected from the toner carrying roller 1 by transferring the toner is transferred to the counter electrode 31 side through the toner passage hole 41 and then adhered to the recording medium 3 as a recording member to form an image. In the apparatus, the printer unit, which is the image forming apparatus of the present invention, is used as the image forming unit, so that the cost can be reduced and the toner can be reduced. The distance between the lifting roller 1 and the toner control electrode substrate 4 is set to a predetermined distance can be maintained, it is possible to perform good image formation.

DESCRIPTION OF SYMBOLS 1 Toner carrying roller 3 Recording medium 4 Toner control electrode board 5 Power supply 6 Control pulse generation means 8 Bias power supply 10 Electric force line 11 Electrode 12 Printer unit 13 Image forming unit 13a Supply roller 13b Stir screw 13c Stir screw 13d Image forming unit case 14 Holder 14a Edge portion 14b Wall surface 14c Opening portion 15 Holder 15a Support plate 15b Support plate 15c Wall surface 15d Wall surface 20 Intermediate transfer belt 21 Drive roller 22 Tension roller 23 Transfer counter roller 24 Counter roller 25 Mark sensor 26 Cleaning blade 27 Transfer roller 28 Paper feed Roller 29 Registration roller pair 30 Paper feed / conveying part 31 Counter electrode 32 Fixing device 33 Rotating shaft 41 Toner passage hole 42 Control electrode 45 Base material 50 Unit holder 50a Upper holder part 50 Lower holder portion 55 the tension applying member 56 supporting plate 501 toner carrying roller 502 hole 504 flying electrode 506 opposite electrode 507 paper

Japanese Patent No. 2910019

Claims (4)

A housing for storing the image forming agent;
An agent carrier that supports the image forming agent that is supported by the housing and faces the outside of the housing through an opening formed on a side surface of the housing;
A plurality of holes are formed, and a sheet-like hole forming member disposed to face the agent carrier with a predetermined interval;
A plurality of flying electrodes provided in the hole forming member corresponding to each of the plurality of holes, and for forming an electric field for selectively flying the image forming agent from the agent carrier toward the holes;
The casing is separate from the casing, and is provided on the side surface of the casing where the opening is formed so as to cover the agent carrier. At least the hole forming member is formed on the wall facing the agent carrier. An opening is formed at a location facing the plurality of holes formed, and the hole forming member is held in the axial direction of the agent carrier on the wall surface of the wall opposite to the side facing the agent carrier, e Bei and positioning means relative position between the agent carrier and the hole forming member to position the porogenic member against the agent carrying member so that a predetermined positional relationship, and
It is a part of the wall of the positioning means on the side facing the agent carrier, and faces the agent carrier upstream of the opening formed in the wall in the direction of rotation of the agent carrier. the edge in contact with the surface of the carrier, so that the distance between the dosage carrying body and the porogenic member becomes a predetermined distance, the positioning of the hole forming member against said agent carrier Going and
An image forming apparatus characterized in that the edge of the positioning means is also used as an agent restricting means for restricting the amount of the agent on the agent carrier. The imaging device according to claim 1.
A holding member for detachably holding the housing;
An opening is formed in the holding member so that the wall portion of the positioning means faces the outside of the holding member when the housing is mounted in the holding member.
The hole forming member is provided on the holding member so as to cover the opening of the holding member;
By mounting the housing in the holding member and bringing the positioning means into contact with the hole forming member through the opening of the holding member, the positioning means positions the hole forming member with respect to the agent carrier. An image forming apparatus characterized by being configured as described above. The imaging device of claim 2,
The hole forming member is made of a flexible material,
An image forming apparatus comprising tension applying means for applying tension to the hole forming member provided on the holding member. A housing for storing the image forming agent, an agent carrier that supports the image forming agent that is supported by the housing and faces the outside of the housing from an opening formed in the housing, A sheet-like hole forming member disposed so as to face the agent carrier at a predetermined interval, and provided in the hole forming member corresponding to each of the plurality of holes, A plurality of flying electrodes for forming an electric field for selectively flying the image forming agent from the agent carrier toward the hole, and a relative position between the agent carrier and the hole forming member is a predetermined position. An image forming means comprising positioning means for positioning the hole forming member with respect to the agent carrier so as to be in a relationship;
A counter electrode disposed to face the agent carrier via the hole forming member, and for forming an electric field that attracts the image forming agent flying from the agent carrier;
Based on the image information, the image forming agent that has been selectively ejected from the agent carrier by the formation of the flying electric field is transferred to the counter electrode side through the hole, and then adhered to the recording member to form an image. In the image forming apparatus to be formed,
An image forming apparatus using the image forming apparatus according to claim 1, 2 or 3 as the image forming means.

Images