JP2013022752A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus, capable of preventing deterioration of image quality due to variations in the amount of toner discharged from each hole or in the accuracy of adhering position thereof.SOLUTION: The image forming apparatus includes: a casing; an agent support roller which supports an image forming agent; a sheet-like hole forming member which has a plurality of holes and is disposed to face the agent support roller with a space therefrom; a plurality of flying electrodes provided on the hole forming member in conformation to the plurality of holes respectively; and a belt member rotatably laid on the side opposite to the side where the agent support roller is located so as to face the hole forming member with a predetermined space. The apparatus further includes a holding member which holds the hole forming member so that at least the area having the plurality of holes of the hole forming member is curved at a curvature substantially equal to the curvature of the agent support roller; and a contact member which brings a curved surface curved at the curvature substantially equal to the curvature of the agent support roller into contact with the belt member located at a position opposed to the area having the plurality of holes of the hole forming member to curve the belt member.

Description

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

  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.). This type of image forming apparatus forms an image directly on a recording paper, a transfer body, or the like by applying the flying toner to a recording paper, a transfer body, or the like.

  FIG. 19 is a configuration diagram illustrating an example of a main configuration of a conventional direct recording type image forming apparatus. In FIG. 19, a toner carrying roller 501 is disposed so that its axis extends in the left-right direction in the figure, 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 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.

  Under the FPC 503, a counter electrode 506 that faces the toner carrying roller 501 through the FPC 503, and a recording paper 507 that is carried on the surface of the belt member 508 that is a conveying unit on the counter electrode 506 and conveyed. Is arranged. In FIG. 19, 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 an 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.

  However, if there is a variation in the position of each hole 502 from the surface of the toner carrying roller 501 through the hole 502 to the surface of the recording paper 507 carried on the belt member 508, recording is performed through each hole 502. Variations occur in the amount of toner discharged onto the paper 507 and the accuracy of the position attached to the surface of the recording paper 507. As described above, when the amount of toner discharged from each hole 502 and the accuracy of the adhesion position vary, there arises a problem that the image quality is deteriorated.

  In the image forming apparatus in which the toner discharged from the hole is once attached to the surface of the transfer member and then transferred from the surface of the transfer member to the recording member to finally form an image on the recording member. If there is variation in the position of each hole in the distance from the surface to the surface of the transfer body through the hole, the same problem as described above occurs.

  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 suppressing deterioration in image quality due to variations in the amount of toner discharged from each hole and the accuracy of the adhesion position. Is to provide.

  In order to achieve the above object, the invention of claim 1 is directed to a housing that stores an image forming agent and an opening that is pivotally supported by the housing and formed in the housing. An agent carrying roller for carrying the stored image forming agent, a sheet-like hole forming member formed with a plurality of holes and facing the agent carrier at a predetermined interval; A plurality of flying electrodes provided on the hole forming member corresponding to each of the holes for forming an electric field for selectively flying the image forming agent from the agent carrier toward the holes, and the agent A belt member that is rotatably stretched to face the hole forming member at a predetermined interval on the side opposite to the side on which the carrying roller is located, and the belt forming member discharges the image forming agent discharged from the hole. The image is directly adhered to the recording member carried on the surface of the recording member. Or the image forming agent discharged from the hole is once attached to the surface of the belt member, and then transferred from the surface of the belt member to the recording member to finally form an image on the recording member. In the forming apparatus, a holding member that holds the hole forming member so that at least a region in which the plurality of holes of the hole forming member are formed is curved with substantially the same curvature as the curvature of the agent carrying roller, and the agent carrying A contact that curves the belt member by causing a curved surface that is curved with substantially the same curvature as that of the roller to abut against the belt member that is positioned opposite the region where the plurality of holes of the hole forming member are formed. And a member.

  In the present invention, at least a region of the hole forming member in which the plurality of holes are formed is curved with a curvature substantially the same as the curvature of the agent carrying roller. As a result, the curvature of the agent carrying roller and the curvature of the region of the hole forming member are substantially the same, so that the interval between the agent carrying roller and the hole forming member in the region is substantially the same in the rotation direction of the agent carrying roller. can do. Further, the belt member located at a position facing the region is bent by the contact member with a curvature substantially the same as the curvature of the agent carrying roller. Accordingly, the curvature of the region of the hole forming member and the curvature of the belt member located in the region are substantially the same, so that the interval between the hole forming member and the belt member in the region is substantially the same in the rotation direction of the agent carrying roller. The same interval can be used. Therefore, the distance from the surface of the agent carrying roller to the surface of the belt member through each hole of the hole forming member can be made substantially the same in the direction of rotation of the agent carrying roller. Accordingly, it is possible to suppress variations in the amount and position of the image forming agent discharged from each hole adhering to the surface of the recording member carried on the surface of the belt member or the surface of the belt member, and the image quality is deteriorated. Can be suppressed.

  As described above, according to the present invention, there is an excellent effect that it is possible to suppress deterioration in image quality due to variations in the amount of toner discharged from each hole and the accuracy of the adhesion position.

FIG. 4 is a diagram illustrating a state of curvature of a toner carrying roller, a toner control unit, and an intermediate transfer belt. 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. (A) Schematic diagram on the printing surface side of toner control means, (b) Explanatory drawing of the toner supply side of toner control means. (A) Schematic diagram on the printing surface side of toner control means, (b) Explanatory drawing of the toner supply side of toner control means. FIG. 2 is a schematic configuration diagram of a printer unit. The side view of a developing unit. (A) The side view of a holder, (b) The partial front view which showed a part of holder when the holder was seen from the front. 1 is a schematic configuration diagram illustrating a main part of an image forming apparatus. FIG. 4 is an enlarged cross-sectional view of the vicinity of a holder of a printer unit and the vicinity of a counter roller as viewed from the toner carrying roller axial direction. FIG. 3 is a plan view of the toner control unit viewed from the side of a counter roller that stretches an intermediate transfer belt. FIG. 4 is a schematic diagram of a printer unit when seal members are provided on the upstream side and the downstream side with respect to the rotation direction of the toner carrying roller. The schematic diagram of the printer unit to which the holder which has a protrusion part was attached. The enlarged view which showed the fitting part vicinity of the holder of a printer unit, and the axis | shaft of a counter roller. (A) Explanatory drawing when the curvature difference between the toner carrying roller and the toner control means is large, (b) Explanatory drawing when the curvature difference between the toner control means and the intermediate transfer belt is large. FIG. 3 is an enlarged cross-sectional view of the vicinity of a holder of a printer unit and the vicinity of a counter roller as viewed from the intermediate transfer belt rotation direction. FIG. 3 is a schematic configuration diagram of another image forming apparatus according to the embodiment. FIG. 4 is an enlarged cross-sectional view of the vicinity of a holder of a printer unit and the vicinity of a counter roller when viewed from the intermediate transfer belt rotation direction when a cleaning member for cleaning the roller surface of the gap adjustment roller is provided. FIG. 10 is a schematic diagram showing a basic configuration of a conventional direct recording apparatus.

  Hereinafter, embodiments of the present invention will be described. First, a direct recording method adapted to the present invention will be described.

FIG. 2 is a schematic configuration diagram of a direct recording method adapted to the present invention.
In this embodiment, a toner carrying roller 1 that is an agent carrying roller that carries the toner T as an image forming agent in a clouded state, a recording medium 3 to which the toner T is attached, and the toner carrying roller 1. And a toner control means 4 having a plurality of toner passage holes 41 arranged between the recording medium 3 and the recording medium 3.

  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 voltage application device 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 at 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 means 4 is a sheet-like hole forming member, and is provided with a plurality of toner passage holes (openings) 41 through which the toner T can pass, and a toner supply side surface (surface on the toner carrying roller 1 side) of the toner control means 4. A control electrode 42 is provided in a ring shape around the toner passage hole 41, and a common electrode 43 common to the plurality of toner passage holes 41 is provided outside the control electrode 42 with respect to the toner passage hole 41 via an insulating region. It has been.

  For example, a control pulse Vc as shown in FIG. 3 is applied from the control pulse generator 6 to the control electrode 42 of the toner control means 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. Further, the bias voltage Vg is always applied to the common electrode 43 from the power supply means 7. The control electrode 42 of the toner control means 4 can operate only around the toner passage hole 41, but on both 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.

  On the recording medium side, a back electrode 31 as an electrode means serving as a bias voltage applying means to which a bias voltage for applying the toner T that has passed through the toner control means 4 to the recording medium 3 is applied to the back surface of the recording medium 3. And a bias voltage Vp from the bias power supply 8 is applied to adhere the toner T that has passed through the toner control means 4 to the recording medium 3. The recording medium 3 may be an intermediate transfer recording medium or recording paper on which an image is once formed and then transferred to paper. For the application of the bias voltage Vp to the recording medium 3, for example, a back electrode 31 is disposed on the back side (side opposite to the toner carrying roller 1) of the recording medium 3, and the recording medium 3 is passed over the back electrode 31. Alternatively, in the case of an intermediate transfer recording medium, a configuration in which electrodes are embedded therein (a configuration in which an electrode on the recording medium side is used as an internal electrode) or a configuration in which a back electrode 31 is disposed on the back surface of the intermediate transfer recording medium can be employed.

  Here, when applying a pulse voltage of the average potential Vs to each of the plurality of electrodes 11 provided on the surface of the toner carrying roller as a means for clouding the toner on the surface of the toner carrying roller 1, between the adjacent electrodes 11. In this case, a two-phase inter-electrode pitch p (or an n-phase phase voltage is applied to each n-th electrode 11) is applied. The relationship between the distance d between the surface of the toner carrying roller 1 and the side surface of the toner carrying roller of the toner control means 4 (meaning the surface on the toner carrying roller 1 side), that is, the toner supply gap, is larger than the pitch between the electrodes). The toner carrying roller 1 and the toner control means 4 are arranged at p <d).

  This is because, in the relationship of p> d, the flying electric field formed on the surface of the electrode 11 of the toner carrying roller 1 interferes with the ON / OFF electric field on the surface of the toner carrying means 1 on the toner carrying roller 1 side, and toner control described later is performed. This is because the loop electric field of the means 4 is disturbed. Therefore, toner adhesion to the surface of the control electrode 42 is likely to occur. Under the condition of p <d, it is possible to reliably prevent the toner from adhering to the control electrode 42, and a good image can be obtained without changing the density even if continuous dots are printed.

  Next, an example of a specific configuration of the toner control unit 4 will be described with reference to FIG. 4A is an explanatory diagram on the printing surface side of the toner control means 4, and FIG. 4B is an explanatory diagram of the toner supply side surface of the toner control means 4. FIG.

  In this example, a ring-shaped control electrode 42 having a width of 10 μm to 100 μm is provided on the surface of the insulating substrate (base material) 45 on the toner supply side (toner carrying roller side) so as to surround the toner passage hole 41. Common electrode for applying a common bias voltage Vg to the plurality of toner passage holes 41 on the same surface as the control electrode 42 through an insulating region formed by the insulating substrate 45 at intervals of 20 μm to 50 μm from 43 is provided.

  The toner passage hole 41 has a diameter of 30 μm to 150 μm, which is determined by the size of the dot diameter to be formed. The control electrode 42 is connected to a lead pattern 42a for connection to a driver circuit (drive circuit) for controlling ON / OFF of the passage of the toner T, and the common electrode 43 is connected to a common lead pattern 43a. Yes. Further, the toner passing hole 41 is opened on the printing surface side (the surface on the recording medium 3 side) of the insulating substrate 45.

  As described above, the common electrode 43 of the toner control unit 4 is configured to surround the outside of the control electrode 42 in a ring shape through the insulating region, so that the bias potential on the recording medium 3 side and the outside of the control electrode 42 are Because the electric force formed between the common electrodes 43 can be formed as an independent line of electric force for each toner passage hole, mutual interference (driving other toner passes) at the time of multi-driving (driving the toner from a plurality of nozzle passage holes) Receiving the state of the hole 41) does not occur.

  Further, by forming the control electrode 42 and the common electrode 43 of the toner control means 4 on the same surface, they can be formed simultaneously in a single manufacturing process, and the electrodes can be made with high accuracy and at low cost.

  Another example of the specific configuration of the toner control unit 4 will be described with reference to FIG. 5A is an explanatory diagram of the toner control unit 4 on the printing surface side, and FIG. 5B is an explanatory diagram of the toner supply side surface of the toner control unit 4. FIG.

  In this example, a ring-shaped control electrode 42 having a width of 10 μm to 100 μm is provided on the surface of the insulating substrate (base material) 45 on the toner supply side (toner carrying roller side) so as to surround the toner passage hole 41. The common electrode 43 for applying a common bias voltage Vg to the plurality of toner passage holes 41 is provided in a solid shape so as to cover the entire vacant space with an interval between the insulating regions of 20 μm to 50 μm.

  As described above, the common electrode 43 of the toner control unit 4 is configured to be solid on the outside of the control electrode 42 via the insulating region, that is, the common electrode 43 is formed over the entire outer region of the control electrode 42. Thus, the electric field of the bias potential on the recording medium 3 side can be shielded, toner adhesion to the control electrode 42 can be reduced, and toner utilization efficiency can be improved.

  A specific method for manufacturing the toner control unit 4 is an insulating member that is an insulating substrate 45, which is a resin film from the viewpoint of cost and manufacturing process, such as polyimide, PET, PEN, PES, etc., and has a thickness of 30 μm. A 100 μm film is used, and an Al deposited film of 0.2 μm to 1 μm is first formed on the film surface. Next, in the photolithography process, after applying a photoresist with a spinner, pre-baking and mask exposure are performed, development is performed, and after the photoresist is heated and cured, Al patterning is performed with an Al etching solution. If an electrode pattern is also required on the back side of the film, it is possible in the same manner as described above, but a pattern used as a mask for hole processing may be formed on the back side. The formation of the through-hole serving as the toner passage hole 41 is caused by positional displacement according to mechanical processing by pressing after pattern formation, excimer laser processing using a pattern formed on the back surface, or dry etching processing such as sputter etching processing. High-accuracy drilling can be performed.

  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 back electrode 31 on the recording medium 3 side.

  In this state, when the bias voltage Vg is applied to the common electrode 43 of the toner control means 4 so that the toner T can pass through the toner passage hole 41 with respect to the control electrode 42 (ON state), FIG. An ON-state voltage Vc-off shown in FIG. 3 is applied when the ON-state voltage Vc-on shown in FIG. 3 is applied and the toner T is in a state where it cannot pass through the toner passage hole 41 (OFF state).

  In this case, the voltage for each of these electrodes 11, 31, 42, 43 is set to a certain value so that the toner control means 4 can pass the toner T of the toner carrying roller 1 toward the recording medium 3. Sometimes, the electric lines of force 10 are formed in a loop shape around the control electrode 42 that controls the passage of toner between the recording medium 3 side and the common electrode 43 of the toner control means 4.

  As a result, the clouded toner 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 unit 4 and lands on the recording medium 3. Therefore, a toner image can be directly formed on the recording medium 3 by performing ON / OFF control (open / close control) of each toner passage hole 41 of the toner control unit 4 according to the image. Since the electric lines of force 10 are formed in a loop shape around the control electrode 42 that controls the passage of toner between the recording medium 3 side and the common electrode 43 of the toner control means 4, Toner adhesion to the periphery of the toner passage hole 41 is reduced, and the use efficiency of the toner is improved by making the toner cloud.

  Next, the printer unit 12 of this embodiment using the toner control means 4 and the toner carrying roller 1 of the direct recording method will be described.

  FIG. 6 is a schematic configuration diagram of the printer unit 12 viewed from the side. The printer unit 12 is mainly composed of three elements: a developing unit 13 that supports the toner carrying roller 1, a toner control unit 4, and a holder 14 to which the toner control unit 4 is attached. The printer units 12 are integrated in a detachable relationship so that the printer unit 12 can be easily assembled and disassembled.

  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 unit 4, at a predetermined interval, the relative position between the toner carrying roller 1 and the toner control unit 4 is set. A holder 14 for determining is interposed between the developing unit 13 and the toner control means 4.

  A method of directly attaching the toner control means 4 to the development unit case 13d of the development unit 13 without using the holder 14 while being curved so as to cover the toner carrying roller 1, for example, is conceivable, but the rigidity of the toner control means 4 is low. Therefore, it is difficult to accurately set and maintain the toner supply gap over the entire area of the toner control unit 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 means 4 is guided over the entire area at an accurate position so that a desired surface shape is formed in the toner control means 4 and the toner supply gap between the toner carrying roller 1 and the toner control means 4 is achieved. It is necessary to position the toner control means 4 with respect to the toner carrying roller 1 so as to be a predetermined interval.

  Therefore, in this embodiment, the holder 14 is provided as a guide member for guiding the toner control means 4 so as to have a desired surface shape over almost the entire area of the toner control means 4 except for the area of the toner passage holes 41 opened in the toner control means 4. . If this holder 14 is used, almost the entire area of the toner control means 4 excluding the area of the toner passage hole 41 is held by the side wall of the holder 14, so that the above-mentioned drawback due to the low rigidity of the toner control means 4 is eliminated. In addition, there is no bending or distortion that causes the toner supply gap to vary in the axial direction of the toner carrying roller near the central portion of the toner carrying roller in the axial direction of the toner carrying means 4. A desired surface shape can be formed and set on the surface 4.

  In the present embodiment, the accuracy of the supply gap and the printing gap is set at a high level, and the maintenance stability of these accuracy is also high. Toner as shown in FIG. The bearing 1b of the carrier roller 1 is used as a reference for mounting the holder 14 (supply gap setting reference), and the holder 14 can change the angle about the shaft 1a of the toner carrier roller 1.

Next, the components of the printer unit 12 will be specifically described.
FIG. 7 is a side view of the developing unit 13 in the printer unit 12. The developing unit 13 of this embodiment uses a two-component developer composed of a magnetic carrier and a nonmagnetic toner. The developing unit 13 may use a one-component developer made of nonmagnetic toner.

  The developing unit 13 supplies a developing unit case 13d in which a developer is stored, a toner carrying roller 1 that is a roller-like toner carrying member carrying toner, and the developer in the developing unit case 13d to the toner carrying roller 1. The toner carrying roller 1 is composed of a magnetic roller 13a, two stirring screws 13b for stirring the developer in the developing unit case 13d, a blade 13c for thinning the toner on the toner carrying roller 1, and the like. 13a, the agitating screw 13b, the blade 13c and the like are housed and provided in the developing unit case 13d.

  The toner carrying roller 1 includes a side plate 13d-1 of the developing unit case 13d, and a side plate (not shown) on the back side of FIG. 7 facing the side plate 13d-1 and the toner carrying roller 1 in the axial direction of the toner carrying roller. Thus, the toner carrying roller 1 is rotatably supported via a shaft 1a and a bearing 1b attached to the shaft 1a, and is driven to rotate by being connected to a motor (not shown). Then, the developer is conveyed to a position facing the toner carrying roller 1 by a mag roller 13a containing a permanent magnet, and a bias is applied to a part of the toner, and the toner potential is applied to the toner carrying roller 1 from the mag roller 13a by the bias potential. Is transferred. The toner transferred to the toner carrying roller 1 becomes a cloud state by the above-described method, etc., is thinned by the blade 13 c by the rotation of the toner carrying roller 1, and is carried to a position facing the toner control means 4. Then, by the above-described method, the clouded toner on the toner carrying roller 1 is placed on an electric field, passes through the toner passage hole 41 of the toner control means 4 and is landed and printed on a recording medium (not shown).

  The toner that has not been used for printing on the toner carrying roller 1 returns to the magnet 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 that has returned to the position facing the mag roller 13a without being copied follows the rotation of the mag roller 13a. Easily scraped or leveled by developer spikes. By repeating this, a substantially constant amount of toner is always carried on the toner carrying roller 1 in a cloud state.

  The developing unit case 13d of the developing unit 13 has an opening on the side (right side in the figure) where the toner carrying roller 1 is supported, and the toner carrying roller 1 is exposed to the outside of the developing unit case 13d from the opening. The configuration is to let This is because the assemblability of the toner carrying roller 1 and single replacement are taken into consideration, and the toner carrying roller 1 can be easily detached from the developing unit 13. The toner carrying roller 1 can be attached to and detached from the developing unit 13 simply by attaching or detaching the bearing 1b attached to the shaft of the toner carrying roller 1 to or from the developing unit case 13d. The shaft 1a of the toner carrying roller 1 is inserted and removed through a notch 13d-2 provided in the portion supporting the toner.

  The opening side surface (the right side surface in the figure) of the developing unit case 13d where the toner carrying roller 1 is supported and exposed is a holder 14 attached so as to cover the toner carrying roller 1 as a lid of the opening side surface. Therefore, there is no concern about toner spillage or scattering from the surface of the developing unit case 13d on the opening side. Further, when the holder 14 is attached to the developing unit case 13d, seal members 13e and 13f are provided on the developing unit case 13d for preventing toner from leaking from the gap between the developing unit case 13d and the holder 14. . Further, a curvature around the shaft 1a of the toner carrying roller 1 for fastening the holder 14 to the developing unit case 13d with a screw on the side plate 13d-1 (including the side plate on the back side in the figure) of the developing unit case 13d. A long hole 13g having a hole is formed.

  FIG. 8A is a side view of the holder 14, and FIG. 8B is a front view (part) thereof. The holder 14 will be described with reference to FIGS. 8A and 8B. The holder 14 is configured so that when the holder 14 is attached to the developing unit 13, the toner control means 4 (the toner passage hole 41 row) faces the toner carrying roller 1 to form and set a predetermined supply gap. is there. The side surface portion 14a on the right side of the holder 14 in FIG. 8A is a portion that guides almost the entire area of the toner control means 4 in order to position the toner control means 4 and form a surface shape (curved shape). The toner control unit 4 is attached so as to be in close contact with the side surface portion 14 a of the holder 14.

  The inner space of the holder 14 has a large space so that the toner carrying roller 1 enters with a margin. This space is narrow so as not to damage the toner carrying roller 1 when the holder 14 is attached or detached or when the angle is changed, or when the holder 14 is attached to the developing unit 13 and the toner carrying roller 1 is rotated. This is also to prevent toner scattering due to airflow in the space.

  Further, at a position where the toner carrying roller 1 and the toner control means 4 of the side surface portion 14a face each other through the holder 14, an opening portion 14c penetrating the side surface portion 14a and the inner space is provided in a row of 41 toner passage holes. It is opened with a shape dimension slightly larger than the row region. Toner flying from the toner carrying roller 1 to the toner control means 4 (line 41 of toner passage holes) is performed through the opening 14c. The opening area of the opening 14c should not be as large as possible. The reason is that the toner control means 4 may be bent, distorted or vibrated in a portion where there is no guide by the side face portion 14a. To prevent this, the toner control means 4 can be guided over a wide range by the side face portion 14a. This is because it is better to reduce the opening area of the opening 14c to such an extent that the toner flying function is not hindered.

  By configuring the holder 14 as described above, the toner control unit 4 can form and set a desired surface shape at an accurate position.

  In addition, the side portion 14d on the front side in FIG. 8A is provided with a “U” -shaped notch 14d-1 that is fitted with the bearing 1b of the toner carrying roller 1 and is surrounded by the convex portion 14e. ing. The fitting relationship between the bearing 1b and the notch 14d-1 is the vertical direction and the horizontal direction of the holder 14 in FIG. 8A (positioning in the horizontal direction is only on the right side), and the center position of the bearing 1b, that is, the toner. The position of the center of the rotation axis of the carrier roller 1 and the center position 4d-2 of the notch 14d-1 are overlapped. That is, this position is an attachment reference (supply gap setting reference) of the holder 14 with respect to the developing unit 13 (toner carrying roller 1), and is a variable angle center of the holder 14. The bearing 1b is fitted to the end of the “U” -shaped notch 14d-1, and in this state, the angle of the holder 14 is changed around the shaft 1a of the toner carrying roller 1, thereby developing unit 13 (toner carrying roller 1). The optimum position and angle of the toner control means 4 (toner passage hole 41 row) can be set.

  Further, as described above, the holder 14 is attached to the developing unit 13 so as to serve as a lid for the opening side surface (the right side surface in FIG. 7) of the developing unit 13. After setting the position and angle of the holder 14, the holder 14 can be fixed to the developing unit 13 by fastening with screws or the like to the two screw holes 14 f and the two long holes 13 g of the developing unit 13.

  Here, from the viewpoint of recent environmental protection, the reuse of the image forming apparatus main body and parts is the responsibility of the manufacturer. In particular, research and development on the configuration, shape, and business model of units and parts that can be reused easily by many manufacturers, as consumable parts such as developing cartridges and printer units 12 that are frequently replaced, and the printer unit 12 have a large impact on the environment. ing. That is, there is a demand for a printer unit 12 that has good assembling and dismantling properties that take reuse into consideration.

  For example, as shown in FIG. 8B, the toner control means 4 is attached to the holder 14 by positioning the toner control means 4 with respect to the side surface portion 14a in the vicinity of both ends of the side surface portion 14a of the holder 14 in the axial direction of the toner carrying roller. A reference pin 14g serving as a reference is provided, and a hole for fitting the reference pin 14g opened in the toner control means 4 is fitted to the reference pin 14g when the toner control means 4 is attached to the side face portion 14a. The toner control means 4 is positioned, and after such positioning, the toner control means 4 is adhered to the side surface portion 14a with an adhesive or adhesive material (including double-sided tape).

  In this embodiment, as shown in FIG. 6, an electrical base material 4 a that drives and controls the toner control unit 4 is integrally connected to the end of the toner control unit 4. This electrical base material 4a is attached to the side surface of the developing unit case 13d. When the toner control means 4 needs to be replaced or reused, the toner control means 4 must be easily detachable from the holder 14, so that after positioning the toner control means 4 with respect to the side surface portion 14a, the toner Each of the electrical base materials 4a at both ends of the control means 4 is pulled by a spring or the like toward the opposite side (left direction in FIG. 6) of the developing unit case 13d to which the holder 14 is attached perpendicular to the toner carrying roller axial direction. It is desirable to apply a method such as applying tension to the toner control means 4 and attaching the electric base material 4 a to the developing unit case 13 d while bringing the toner control means 4 into close contact with the holder 14.

  If the desired surface shape cannot be formed even if the toner control means 4 is attached to the holder 14 due to bending or distortion, a thin stainless steel plate with attention to electrical defects (such as short circuit and leak). Such a reinforcing material may be attached to the toner control means 4 or the holder 14.

  Here, the bearing 1 b that supports the toner carrying roller 1 on the developing unit 13 and is fitted to the holder 14 is replaced with a bearing that fits the holder 14 and a bearing that supports the toner carrying roller 1 on the developing unit 13. You may divide into two bearings. In other words, a bearing that serves as a reference when the holder 14 is positioned with high accuracy with respect to the toner carrying roller 1 is provided separately from the bearing that rotatably supports the toner carrying roller 1 with respect to the developing unit 13.

  Usually, the bearing used for the developing unit is generally a resin-made sliding bearing from the standpoint of insulation characteristics and cost, and the toner carrying roller 1 itself does not have a problem of rotational accuracy, and may be a sliding bearing. However, in this embodiment, since the position of the holder 14, that is, the position of the toner control means 4 is determined with reference to the bearing, the bearing accuracy becomes a problem when the toner supply gap is several tens of μm. Therefore, the bearing fitted to the holder 14 is a separate bearing with high accuracy from the bearing that supports the toner carrying roller 1, and the use of a highly accurate bearing such as a rolling ball bearing causes a problem of bearing accuracy. Can be suppressed.

  FIG. 9 shows a full color using an intermediate transfer belt 20 as a transfer medium for primarily carrying images of each color imaged on the surface by each image forming device and transferring the images of each color to a recording member all at once. 1 is a schematic side view illustrating a configuration of an image forming unit of an image forming apparatus that forms an image.

  A toner image is formed on the intermediate transfer belt 20 by the printer unit 12 of the embodiment that performs toner clouding and toner passing ON / OFF control by the toner control means 4, and the toner image is intermediated during one rotation of the intermediate transfer belt 20. The image forming apparatus forms a color image by sequentially superimposing colors on the transfer belt 20 for each color. 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 the electrophotographic image forming apparatus using the photosensitive member and the 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 (back electrode) on the side of the intermediate transfer belt 20 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 spaced along the moving direction of the intermediate transfer belt 20. Are arranged sequentially.

  Each printer unit 12 is placed sideways with respect to the main body of the apparatus, and faces the opposing roller 24 corresponding to each color with the intermediate transfer belt 20 interposed therebetween, and the toner control means 4 of the printer unit 12 prints on the intermediate transfer belt 20. They are set apart by a predetermined interval (several hundred μm), which is called a copying 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.

  Further, the image forming apparatus main body is provided with a rotation shaft 33, and the intermediate transfer belt 20, the transfer section, the fixing device 32, and the like with respect to the apparatus main body are left with the printer unit 12 and the sheet feeding / conveying section 30 remaining in the apparatus main body. Can be integrally separated.

  Each printer unit 12 stores toner of each color of yellow (Y), magenta (M), cyan (C), and black (Bk), and is clouded by the toner carrying roller 1 in each printer unit 12. The toner conveyed to a position facing the toner control unit 4 is selectively transferred onto the intermediate transfer belt 20 by the control electric field of toner control ON / OFF of the control electrode 42 at the toner passing hole 41 position of the toner control unit 4. Flyed. Then, the respective color toner images are formed on the intermediate transfer belt 20 so that the four color toner images are superimposed, and 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, and the sheet is conveyed by the sheet feeding roller 28, the registration roller pair 29, etc. 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 removed from the intermediate transfer belt 20 by a cleaning blade 26 as a cleaning unit, and the intermediate transfer belt 20 prepares for the next image formation.

  In the image forming apparatus of the present embodiment, four color toner images are superimposed on the intermediate transfer belt 20 by the printer unit 12, and a color image is output by one rotation of the intermediate transfer belt 20, so that high-quality color is achieved. An image can be output at high speed, and the image forming apparatus can be downsized.

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

  10 is an enlarged cross-sectional view of the vicinity of the holder of the printer unit 12 and the vicinity of the opposing roller as seen from the axial direction of the toner carrying roller. FIG. 11 shows the toner control unit 4 viewed from the side of the opposing roller 24 on which the intermediate transfer belt 20 is stretched. FIG. The optimal installation position of the toner control means 4 is that the distribution center plane of the plurality of toner passage holes 41 formed in the toner control means 4 is a straight line connecting the axial centers of the toner carrying roller 1 and the opposing roller 24. The position is orthogonal.

  The toner control means 4 is provided with toner passage holes 41 for flying the toner in an eight-row staggered arrangement as shown in FIG. 11, and the toner in the image forming flow direction (direction orthogonal to the toner carrying roller axial direction). The distribution distance from end to end of the passage hole 41 is 2 mm to 3 mm. Note that the distribution of the toner passage holes 41 provided in the toner control unit 4 is such that all the toner passage holes 41 are accommodated in the openings 14 c of the holder 14.

  In this embodiment, as shown in FIG. 6, the holder 14 can be rotated around the shaft 1 a of the toner carrying roller 1 so that the toner control means 4 is in an optimal position when the printer unit 12 is installed. Also, as shown in FIG. 12, seal members are provided on the upstream side and the downstream side with respect to the rotation direction of the toner carrying roller 1 to prevent the toner from leaking outside. Although the holder 14 is rotatable with respect to the printer unit 12, the rotation limit position of the holder 14 is such that the opening 14 c of the holder 14 is surrounded by the upstream and downstream seal members on the toner carrying roller 1. It is set to fit within the area. Further, the electrical base material 4 a is allowed to freely move along the side surface of the printer unit 12 in accordance with the rotation of the holder 14 that rotates about the axis of the toner carrying roller 1.

  Here, in order to easily install the toner control means 4 at an optimum position in the printer unit 12 of each color, the holder 14 has a protrusion 140 having a concave shape 140a toward the apparatus main body as shown in FIG. It is good to provide.

  The printer unit 12 is inserted in the horizontal direction of FIG. 9 along a rail or groove (not shown) extending from the left in the drawing to the right in the drawing, thereby facilitating the exchange of the printer unit 12. The printer unit 12 is configured to be pressed from behind by a spring (not shown) provided on the exterior cover by closing an exterior cover (not shown) of the apparatus body after being inserted into the apparatus body. Is pressed against the intermediate transfer belt in the apparatus main body. At that time, as shown in FIG. 14, the protrusion 14 of the holder 14 meshes with the shaft 24 a of the opposing roller 24 on the apparatus main body side, and the holder 14 rotates around the shaft 1 a of the toner carrying roller 1 by abutting. The position is determined. As a result, even if the axis center of the toner carrying roller 1 and the axis center of the opposing roller 24 are not located on the same straight line in the horizontal direction, the holder 14 is guided to the protruding portion 140 so Against. Therefore, the distance between the toner control unit 4 and the intermediate transfer belt 20 is optimally regulated for each color printer unit 12 so as to be an optimum distance for image formation.

  Also, if a bearing is attached to the shaft 24a of the opposing roller 24 and the protruding portion 140 of the holder 14 abuts against the bearing, friction with the protruding portion 140 of the holder 14 due to the rotation of the opposing roller 24 is suppressed. Is more desirable.

  Here, as shown in FIG. 15A, if the difference in curvature between the toner carrying roller 1 and the toner control means 4 is large, the gap between the toner carrying roller 1 and the toner control means 4 becomes non-uniform. The amount of toner discharged from the toner passage hole 41 varies depending on the position of the toner passage hole 41.

  Therefore, as shown in FIG. 15B, the gap between the toner carrying roller 1 and the toner control means 4 is reduced by making the curvatures of the toner carrying roller 1 and the toner control means 4 substantially the same and reducing the difference in curvature. Therefore, the amount of toner discharged from the toner passage hole 41 can be prevented from varying depending on the position of the toner passage hole. However, if there is a difference in curvature between the toner control unit 4 and the intermediate transfer belt, the position where the toner discharged from the toner passage hole 41 of the toner control unit 4 lands on the surface of the intermediate transfer belt 20 (attachment position). ) Will vary in accuracy.

  Therefore, in the present embodiment, as shown in FIG. 14 and the like, the toner control unit 4 and the toner control unit 4 are in contact with the surface of the intermediate transfer belt 20 so as to be rotatable. A gap adjusting roller 50 that adjusts the distance from the intermediate transfer belt 20 to a predetermined gap is provided. The gap adjusting roller 50 is provided coaxially with the rotation shaft of the toner carrying roller 1 and is held rotatably around the shaft so as to follow the rotation of the intermediate transfer belt 20.

  FIG. 16 is an enlarged cross-sectional view of the vicinity of the holder of the printer unit 12 and the vicinity of the opposing roller as viewed from the intermediate transfer belt rotation direction. As shown in FIG. 16, the gap adjusting roller 50 has an opening 14 h (FIG. 8) formed in the holder 14 so as to protrude toward the intermediate transfer belt 20 from the toner control means 4 attached to the side wall 14 a of the holder 14. Exposed). Further, a gap adjusting roller 50 is provided in the toner carrying roller axial direction inside of the holder 140 in the rotation axis direction of the toner carrying roller 1, that is, inside the holder 14.

  Further, the gap adjusting roller 50 is brought into contact with the non-image areas at both ends on the outer side in the axial direction of the toner carrying roller from the image area of the intermediate transfer belt 20. As a result, it is possible to prevent the toner image formed in the image area of the intermediate transfer belt 20 from contacting the gap adjusting roller 50 to disturb the toner image.

  As shown in FIG. 1, the gap adjusting roller 50 has a curved surface curved with substantially the same curvature as that of the toner carrying roller 1 at a position facing a region where the plurality of toner passage holes 41 of the toner control unit 4 are formed. The intermediate transfer belt 20 is in contact with a certain intermediate transfer belt 20 and is curved so as to be wound around the gap adjusting roller 50. Thus, by winding the intermediate transfer belt 20 around the gap adjustment roller 50, the curvature of the intermediate transfer belt 20 can follow the curvature of the gap adjustment roller 50.

  Further, the holder 14 holds the toner control unit 4 so that at least a region of the toner control unit 4 in which the plurality of toner passage holes 41 are formed is curved with substantially the same curvature as that of the toner carrying roller 1.

  As described above, in the present embodiment, at least the region in which the plurality of toner passage holes 41 of the toner control unit 4 are formed is curved with substantially the same curvature as that of the toner carrying roller 1. And a difference in curvature between the toner control unit 4 and the toner control unit 4 can be reduced. Therefore, the interval between the toner carrying roller 1 and the toner control means 4 in the region can be made substantially the same over the rotation direction of the toner carrying roller. Further, since the intermediate transfer belt 20 located at a position facing the region is curved by the gap adjusting roller 50 with substantially the same curvature as that of the toner carrying roller 1, the toner control unit 4 and the intermediate transfer belt 20 in the region are curved. The difference in curvature can be reduced. Therefore, the interval between the toner control unit 4 and the intermediate transfer belt 20 in the region can be made substantially the same in the rotation direction of the toner carrying roller.

  Therefore, in the image forming apparatus of this embodiment, the distance from the surface of the toner carrying roller 1 to the surface of the intermediate transfer belt 20 through each toner passage hole 41 of the toner control unit 4 is determined in the toner carrying roller rotation direction. The amount of toner discharged from each toner passage hole 41 and adhered to the surface of the intermediate transfer belt 20 can be suppressed from varying, and the deterioration of image quality can be suppressed. Can do.

  The image forming apparatus of the type that prints the toner of each color from the printer unit 12 of each color directly on the paper carried on the surface of the paper transport belt stretched by a plurality of rollers is also described above. By adopting such a configuration, the same effect as described above can be obtained. That is, at least the region where the plurality of toner passage holes 41 of the toner control unit 4 are formed is held by the holder 14 so as to be curved with substantially the same curvature as that of the toner carrying roller 1, and the curvature of the toner carrying roller 1 A curved surface that is curved with substantially the same curvature is brought into contact with the sheet conveying belt at a position facing the region, and the sheet conveying belt is bent by the gap adjusting roller 50. Thereby, the distance from the surface of the toner carrying roller 1 to the surface of the paper conveying belt through each toner passage hole 41 of the toner control means 4 can be made substantially the same in the direction of rotation of the toner carrying roller. Variations in the amount and position of the toner discharged from the passage hole 41 and adhered to the surface of the sheet carried on the surface of the sheet conveying belt can be suppressed, and deterioration in image quality can be suppressed.

  As shown in FIG. 17, the image forming apparatus including the printer unit 12 may be configured such that a plurality of printer units 12 are installed on the intermediate transfer belt 20 from above the apparatus.

  As shown in FIG. 17, when the peripheral surface of each intermediate transfer belt 20 that faces each printer unit 20 is above the apparatus, the tension (stretched state) of the intermediate transfer belt 20 is attached to the apparatus main body. It is loosened before the printer unit 12 is set, and when the printer unit 12 is mounted on the apparatus main body, the intermediate transfer belt 20 is pressed downward by the gap adjusting roller, so that a predetermined tension capable of forming an image is set. And good.

  At this time, the intermediate transfer belt 20 is stretched so that the peripheral surface of the intermediate transfer belt 20 facing each printer unit 12 has one curvature radius, so that the diameter of the gap adjusting roller 50 is the same in all the printer units 12. It can be.

  Further, if the gap adjusting roller 50 is a bearing, it can be smoothly rotated around the rotation axis of the toner carrying roller 1, and fluctuations in the gap between the holder 14 and the intermediate transfer belt 20 due to vibration can be reduced.

  Here, if there is a foreign object between the roller surface 50a of the gap adjusting roller 50 and the surface of the intermediate transfer belt 20, the gap between the toner control means 4 and the intermediate transfer belt 20 may not be maintained at a predetermined interval. There is. Therefore, as shown in FIG. 18, a cleaning member 61 is provided as a cleaning means for cleaning the roller surface 50a of the gap adjusting roller 50, and foreign matters such as toner adhered to the gap adjusting roller 50 roller surface 50a are removed by the cleaning member 61. By doing so, the gap between the toner control means 4 and the intermediate transfer belt 20 can be kept at a predetermined interval.

  Further, the contact range of the intermediate transfer belt 20 with the cleaning blades 26 and 60 which are cleaning means for cleaning the surface of the intermediate transfer belt 20 shown in FIG. 9 and FIG. 17 is the intermediate transfer belt width direction (toner carrying roller shaft). (Direction) extends not only to the image area but also to the non-image area. As a result, foreign matters such as toner adhering not only to the image area of the intermediate transfer belt 20 but also to the non-image area can be removed by the cleaning blades 26 and 60, and thus contact the non-image area of the intermediate transfer belt 20. The amount of foreign matter such as toner adhering to the roller surface 50a of the gap adjusting roller 50 can be reduced, and the gap between the toner control means 4 and the intermediate transfer belt 20 can be kept at a predetermined interval.

  Further, by subjecting the roller surface 50a of the gap adjusting roller 50 to fluorine treatment, it is possible to prevent foreign matters such as toner from adhering to the roller surface 50a of the gap adjusting roller 50.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A housing such as a developing unit case 13d that stores an image forming agent such as toner and the like, and an image forming agent that is supported in the housing and supported by the housing from the opening formed in the housing and facing the outside of the housing. A sheet-like sheet of toner control means 4 and the like, which is formed with an agent-carrying roller such as the toner-carrying roller 1 and a plurality of holes such as a toner passage hole 41 and arranged to face the agent-carrying roller at a predetermined interval. And a plurality of control electrodes for forming an electric field that is provided in the hole forming member corresponding to each of the plurality of holes and that selectively causes the image forming agent to fly toward the holes from the agent carrying roller. A flying electrode such as 42, and a belt member such as an intermediate transfer belt 20 that is rotatably stretched opposite to the hole forming member at a predetermined interval on the side opposite to the side where the agent carrying roller is located, Discharged from the hole The image forming agent is directly attached to the recording member carried on the surface of the belt member to form an image on the recording member, or the image forming agent discharged from the hole is once attached to the surface of the belt member, and then the belt member. In an image forming apparatus for transferring an image from a surface of a recording medium to a recording member and finally forming an image on the recording member, at least a region where a plurality of holes of the hole forming member are formed is curved with a curvature substantially the same as the curvature of the agent carrying roller. The holding member such as the holder 14 that holds the hole forming member and the curved surface that is curved with substantially the same curvature as that of the agent-carrying roller are positioned at positions that face the region where the plurality of holes of the hole forming member are formed. And a contact member such as a gap adjusting roller 50 which is brought into contact with a certain belt member to bend the belt member. According to this, as described in the above embodiment, it is possible to prevent the image quality from deteriorating.
(Aspect B)
In (Aspect A), the holding member is provided in the housing so as to cover the agent-carrying roller, and at least openings are formed at positions facing the plurality of holes formed in the hole forming member. The hole forming member is held in the axial direction of the agent carrying roller by its own side wall, and the hole forming member is positioned with respect to the agent carrying body so that the relative position between the agent carrying roller and the hole forming member is in a predetermined positional relationship. do. According to this, since the holding member holds the hole forming member in the axial direction of the agent carrying roller on the side wall as described in the above embodiment, the hole forming member is held by the holding member only at both ends in the axial direction of the agent carrying roller. It is possible to suppress the occurrence of bending or the like in the hole forming member such that the interval between the agent carrying roller and the hole forming member varies in the axial direction of the agent carrying roller.
(Aspect C)
In (Aspect A) or (Aspect B), the agent carrying roller, the casing, the contact member, the hole forming member, and the holding member are integrated into a cartridge. According to this, as described in the above embodiment, the gap accuracy between the agent carrying roller and the hole forming member can be improved, and the unit can be easily replaced.
(Aspect D)
In (Aspect A), (Aspect B), or (Aspect C), contact member cleaning means for cleaning the curved surface of the contact member is provided. According to this, as described in the above embodiment, it is possible to reduce the amount of toner adhering to the circumferential surface of the gap adjusting roller and to suppress the fluctuation of the gap between the holder and the intermediate transfer belt.
(Aspect E)
In (Aspect A), (Aspect B), (Aspect C) or (Aspect D), a belt member cleaning member for cleaning the end of the belt member is provided. According to this, as described in the above embodiment, it is possible to reduce the amount of toner adhering to the circumferential surface of the gap adjusting roller and to suppress the fluctuation of the gap between the holder and the intermediate transfer belt.
(Aspect F)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D) or (Aspect E), the contact member is a bearing. According to this, as described in the above embodiment, the gap adjustment roller can be smoothly rotated to reduce the vibration, and the gap fluctuation between the holder and the intermediate transfer member due to the vibration can be reduced.
(Aspect G)
In (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E) or (Aspect F), the curved surface of the contact member is subjected to fluorine treatment. According to this, as described in the above embodiment, it is possible to suppress the adhesion of foreign matter to the surface of the gap adjusting roller.
(Aspect H)
In an image forming apparatus provided with an image forming means for forming an image on a recording medium, the image forming means includes (Aspect A), (Aspect B), (Aspect C), (Aspect D), (Aspect E). ), (Aspect F) or (Aspect G). According to this, as described in the above-described embodiment, it is possible to suppress the recording characteristics (image quality) from being significantly lowered and perform good image formation.

DESCRIPTION OF SYMBOLS 1 Toner carrying roller 1a Shaft 1b Bearing 3 Recording medium 4 Toner control means 4a Electrical base material 4d Center position 5 Voltage application device 6 Control pulse generator 7 Power supply means 8 Bias power supply 10 Electric force line 11 Electrode 12 Printer unit 13 Development unit 13a Mag roller 13b Stirring screw 13c Blade 13d Development unit case 13d-1 Side plate 13e Seal member 13f Seal member 13g Long hole 14 Holder 14a Side surface portion 14c Open portion 14d Side surface portion 14e Protrusion portion 14f Screw hole 14g Reference pin 14h Opening portion 20 Intermediate transfer belt DESCRIPTION OF SYMBOLS 21 Drive roller 22 Tension roller 23 Transfer facing roller 24 Counter roller 24a Shaft 25 Mark sensor 26 Cleaning blade 27 Transfer roller 28 Paper feed roller 29 Registration roller pair 30 Paper feed conveyance 31 Rear electrode 32 Fixing device 33 Rotating shaft 41 Toner passage hole 42 Control electrode 42a Lead pattern 43 Common electrode 43a Lead pattern 45 Insulating substrate 50 Gap adjusting roller 50 Roller surface 60 Cleaning blade 61 Cleaning member 140 Protruding portion 140a Concave shape 501 Toner carrying Roller 502 Hole 504 Flying electrode 506 Counter electrode 507 Recording paper 508 Belt member

Japanese Patent No. 2910019

Claims (9)

A housing for storing the image forming agent;
An agent carrying roller that is pivotally supported by the housing and faces the outside of the housing from an opening formed in the housing, and carries an image forming agent housed in 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;
A belt member that is rotatably stretched so as to face the hole forming member at a predetermined interval on the side opposite to the side where the agent carrying roller is located;
The image forming agent discharged from the hole is directly attached to the recording member carried on the surface of the belt member to form an image on the recording member, or the image forming agent discharged from the hole is applied to the belt member. In an image forming apparatus that once adheres to the surface, then transfers the image from the surface of the belt member to a recording member and finally forms an image on the recording member.
A holding member that holds the hole forming member so that at least a region where the plurality of holes of the hole forming member are formed is curved with substantially the same curvature as that of the agent-carrying roller;
A curved surface that is curved with substantially the same curvature as the curvature of the agent-carrying roller is brought into contact with the belt member at a position facing the region where the plurality of holes of the hole forming member are formed, thereby bending the belt member. An image forming apparatus comprising: an abutting member to be moved. The image forming apparatus according to claim 1.
The holding member is provided in the housing so as to cover the agent-carrying roller, and at least the hole is formed on its side wall in which openings are formed at positions facing the plurality of holes formed in the hole forming member. The forming member is held in the axial direction of the agent carrying roller, and the hole forming member is positioned with respect to the agent carrying body so that the relative position between the agent carrying roller and the hole forming member is in a predetermined positional relationship. Image forming apparatus. The image forming apparatus according to claim 1 or 2,
The holding member is rotatable with respect to the housing around the rotation axis of the agent carrying roller,
The holding member is formed with a protruding portion that protrudes outward from the surface of the hole forming member attached to the side wall and has a concave shape,
The hole forming member is positioned with respect to the image forming apparatus main body side by engaging the rotating shaft of the support roller, which is provided on the image forming apparatus main body side and the belt member is stretched and supported. An image forming apparatus. The image forming apparatus according to claim 1, 2 or 3.
An image forming apparatus, wherein the agent carrying roller, the casing, the contact member, the hole forming member, and the holding member are integrated into a cartridge that is detachable from the apparatus main body. The image forming apparatus according to claim 1, 2, 3, or 4.
An image forming apparatus comprising: a contact member cleaning means for cleaning the curved surface of the contact member. The image forming apparatus according to claim 1, 2, 3, 4, or 5.
The contact member is in contact with both ends of the belt member in the axial direction of the agent carrying roller,
An image forming apparatus comprising: belt member cleaning means for cleaning at least both ends of the belt member in the axial direction of the agent carrying roller. The image forming apparatus according to claim 1, 2, 3, 4, 5 or 6.
An image forming apparatus, wherein the contact member is a rotating member provided coaxially with the agent carrying roller. The image forming apparatus according to claim 7.
An image forming apparatus, wherein the rotating member is a bearing. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6, 7 or 8.
An image forming apparatus, wherein the curved surface of the contact member is subjected to fluorine treatment.

Images