JPH11263035A - Imaging method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remove toner adhering to cover an opening surely by providing a process in which a developer layer carried on a carrying means abuts, at least once, against a developer deposited on the surface of a developer passage control means on the side of the carrying means during an interval when the developer does not pass through a developer passing hole. SOLUTION: An FPC(flexible print circuit) control member 11 is provided with a developer passing hole 21, a control electrode 22, and a guard electrode 23 coated with resin 24 and a toner layer 27 covering an opening. A belt cleaning 50 for removing a toner image or dirt on the image receiving means, i.e., a belt 44, of an imaging apparatus is disposed oppositely to a roller 42 for driving the belt 44. Guide belts of polyester terephthalate tape are provided at the opposite ends of the belt in the breadthwise direction while being overlapped. When the overlapped part is set to come under a head, the toner layer on a sleeve 1 can about against the toner layer 27 on the FPC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a facsimile, and a printer, and more particularly, to a developing method in which a voltage is applied to a developer control electrode of a control member having an opening according to an image signal input from the outside. The present invention relates to an image forming method for controlling the flight of toner from an agent carrier to a back electrode facing the same and to apply toner to a recording medium located between the control electrode and the back electrode for development, and a cleaning technique for an apparatus.

[0002]

2. Description of the Related Art In recent years, a large number of documents have been handled in offices as personal computers have been improved in capacity, and printers and copiers having high processing capabilities have become widespread due to advances in network technology. On the other hand, with the rapid spread of ink jet printers and the like, color documents are also increasing. However, engines capable of outputting satisfactory black-and-white and color documents including speed are under development and are expected to appear. As one of them, there is a toner jet method in which toner is caused to fly on recording paper by the action of an electric field to form an image. Hereinafter, this image forming technique will be described with reference to the drawings.

FIG. 7 shows, for example, US Pat. No. 3,689,9.
This is an image forming apparatus described in Japanese Patent No. 35-35.

In FIG. 7, toner in a developer carrying member 81 passes through an opening 87 provided in a control member 83 and adheres on a recording paper 88. Here, the control member 83 having the opening 87 includes an insulating layer 86, a control electrode 84 formed on one surface of the insulating layer 86, and a base electrode 85 formed on the other surface. The toner flowing from the developer carrier 81 to the control member 83 is controlled by a control voltage applied through the lead wires 89 and 90 at the opening 87, and the passed toner is pulled by the back electrode 91,
As a result, a toner image is formed on the recording paper 88.

However, in such a configuration, there is a serious problem that the toner is deposited so as to cover the opening 87 and causes clogging. If the toner is clogged in the opening, image quality is remarkably deteriorated, for example, white spots occur in an image formed on recording paper.

[0006] To solve this problem, the following cleaning method has been proposed.

For example, Japanese Patent Laying-Open No. 58-44457 proposes an apparatus for applying an AC bias between a developer carrying means 81 and a control member 83 to make toner vibrate. In such an apparatus, the moving toner flows through the opening 87.
Since the vicinity is cleaned, clogging is alleviated.

Further, in Japanese Patent Application Laid-Open No. 4-44063, when the image forming operation is stopped, a voltage having a polarity opposite to the printing voltage is applied to the control member while applying a stronger ultrasonic vibration to the control member than during image formation. A device has been proposed. In such an apparatus, when the image forming operation is stopped,
The control unit is ultrasonically vibrated, and the toner attached near the toner passage opening is separated from the opening 87 and can be removed.

[0009]

However, the above-described cleaning method has the following problems.

First, in the method of recovering the toner adhered so as to cover the opening by applying an AC bias, a new power supply is required, and the applied voltage is large, so that the leakage tends to increase. In some cases, the head may be destroyed.

Next, in the method of recovering by applying an ultrasonic wave, heat is easily generated, the toner may be melted, and the effect as expected is not exhibited.

The present invention has been made to solve the above problems, and
An object of the present invention is to provide a method and an apparatus capable of reliably removing toner adhered so as to cover an opening with a simple configuration.

[0013]

An image forming method according to the present invention comprises: a developer carrying means for carrying and transporting a charged developer;
A developer passage control unit having a plurality of developer passage holes for allowing the developer to pass therethrough, and controlling passage of the developer supplied from the developer carrying unit in accordance with an external image signal; A method for forming an image using an image forming apparatus having at least in this order an image receiving means that land on a developer carrying means during a period in which the developer does not pass through the developer passage hole. A step of contacting the developer layer carried on at least once with the developer deposited on the surface of the developer carrying means on the side of the developer carrying means.

The contact makes it possible to apply a mechanical impact to the toner layer covering the developer passage hole, and to collect a part of the toner in the developer tagging means. Can be efficiently removed.

During the contacting step, the developer carrying means is preferably rotating. The rotation speed is 20-4
00 mm / sec is preferable.

As a method of contacting, the distance between the developer passage control means and the developer carrying means is varied, or the thickness of the developer layer on the developer carrying means opposed to the developer passage control means is varied. This can be achieved by:

When the image forming operation is continuously performed on the image receiving means, the contacting step is performed during a predetermined period from the completion of one image forming operation to the start of the next image forming operation. Is preferred. Further, it is preferable that the operation is performed during a predetermined period from immediately after the power of the image forming apparatus is turned on to when the image forming operation is started. Further, after a paper jam occurs in the image forming apparatus, the paper jam is performed during a predetermined period from the time when the operation for removing the jammed paper from the inside of the image forming apparatus is completed to the time when the image forming operation is restarted. preferable.

An electric field forming means for forming an electric field between the developer passing means and the developer passing control means is provided at a position opposed to the developer passing control means via the image receiving means, and the charged developer flows toward the image receiving means during the contact. It is preferable to form an electrostatic field between the electric field forming means and the developer passage control means so as to move. With this configuration, the toner powder generated by the contact can be drawn into the image receiving unit by the electrostatic field.

Further, an electrostatic field is provided between the developer carrying means and the developer passage controlling means so that the developer deposited on the surface of the developer passing controlling means moves toward the developer carrying means during the contact. Is preferably formed. With such a configuration, the toner powder can be returned to the developer carrying unit side.

Further, it is preferable to have a cleaning means for removing the developer which has moved onto the electric field forming means during the contact.

It is preferable that an electrostatic field is formed between the transfer means and the image receiving means so that the developer attached to the transfer means moves toward the image receiving means during the contact.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described.
Hereinafter, description will be given based on the drawings.

FIG. 1 is a schematic view showing a developer carrying means, which comprises a sleeve 1, a toner regulating blade 2, a toner scraping and supply roller 3, a toner stirring means 5, and a frame 6. The sleeve 1 carries and conveys the toner, has a diameter of 16 to 18 mm, and has a surface roughness of about Rmax = 1 on which blast processing has been performed.
Rotate at ~ 400 mm / sec. In the present embodiment,
Although the sleeve is used with being grounded, the present invention is not limited to this, and a DC or AC voltage may be applied. Toner regulating blade 2
Is formed by forming one to three layers of toner on a sleeve and further charging the toner. An elastic material such as a urethane rubber sheet having a thickness of about 1 mm is placed at a position of 3 to 4 mm on one end of a phosphor bronze plate having a thickness of about 0.5 mm. A member is attached and abuts in the counter direction with respect to the rotation direction of the sleeve.
In this embodiment, the toner is negatively charged. The toner scraping and supply roller 3 scrapes excess toner and further supplies toner to the sleeve.
A synthetic rubber such as urethane sponge is wrapped around a metal shaft of about m to have an outer diameter of about 12 mm, and rotates in the same direction as the sleeve. The amount of bite into the sleeve is 0.1
A range of ２2 mm is preferred.

FIG. 2 is a schematic view showing the developer control means (head portion) in the vicinity of the sleeve 1 and is composed of a control member 11 called a flexible print circuit (hereinafter, FPC) and an FPC holding frame 12. I have.
Although the FPC 11 is fixed to the FPC holding frame 12, this frame is configured to be movable independently of the sleeve. The distance lk between the sleeve and the FPC is 0 to 2
It is about 00 μm, usually about 50 μm. FPC1
Reference numeral 1 denotes a flexible insulating member 20 having a thickness of 50 to 70 μm.
Opening (developer passage hole) 21 and a thickness of about 1 on the sleeve 1 side
A control electrode 22 having a thickness of 0 μm and a guard electrode 23 having a thickness of about 10 μm on the opposite side for narrowing down the toner dots are coated with a resin 24 having a thickness of 1 to 2 μm. In this embodiment, the control electrode has 30
A voltage was applied at 0 V or less, and a voltage of -100 V was applied to the guard electrode. The diameter of the opening 21 is 50 to 200 μm.
m is preferably about 130 μm. When the openings are composed of a plurality of rows, it is preferable that the shortest distances from each row to the surface of the developer layer on the sleeve are all equal. In this figure, 26 is a toner layer on the sleeve, and 27 is a toner layer covering the opening.

FIG. 3 is an overall schematic diagram of the image forming apparatus. Such an image apparatus can have heads corresponding to colors such as yellow, magenta, cyan, and black, and can form a color image. FIG. 3 shows only two heads for simplicity. As shown in FIG. 3, the image forming apparatus includes an intermediate image holding belt 4 serving as an image receiving unit facing the head portion.
4 has a belt driving roller 42 and a grounding roller 43, and includes a back electrode 45 and a power supply 46 via an intermediate image holding belt. The back electrode may be a metal plate or a film in which a conductive filler is dispersed in a resin. Although a voltage of about 500 to 2000 V is applied to the back electrode, a voltage of 1000 V is applied in the present embodiment.

A belt cleaning 50 is pressed against the intermediate image holding belt so as to face the belt driving roller. This is intended to remove toner images or stains on the intermediate image holding belt.

In the moving direction of the intermediate image holding belt, transfer means (separable transfer roller 47) for transferring an image formed on the intermediate image holding belt onto recording paper and its transfer power source 4
And a fixing device 49 for fixing a transferred image on recording paper. The intermediate image holding belt has a thickness of 15
It is an endless type in which conductive carbon is dispersed in polycarbonate of about 0 μm.
40 mm. The belt driving roller and the ground roller have a diameter of about 25 to 30 mm. The transfer roller is 8
A urethane sponge is wound around the shaft core of
mm, and the resistance value is about 10 ⁷ Ω (when 500 V is applied).

In such an apparatus, when a voltage equal to or higher than a predetermined value is applied to the control electrode in response to an external signal, an electric field formed between the sleeve and the back electrode is exposed, or the electric field between the sleeve and the control electrode is exposed. Electric fields are formed therebetween, and the electric fields directly or indirectly pull the toner toward the back electrode, and the toner lands on the intermediate image holding belt to form an image. Conversely, when a voltage equal to or less than a predetermined value is applied to the control electrode, an electric field formed between the sleeve and the back electrode is blocked, and the toner does not land on the intermediate image holding belt, so that no image is formed. Such an operation is formed on the intermediate image holding belt using a head corresponding to, for example, yellow, magenta, cyan, and black,
Then, the image is transferred onto a recording paper by a transfer roller and further fixed by a fixing device 49, whereby a color image can be formed.

Some of the contact means will be specifically described below, but it goes without saying that the present invention can be applied to, for example, a single head for black and white. Further, the object of the present invention can be achieved without being limited to the following means as long as the contact can be made.

(Embodiment 1) An embodiment of the present invention in which a toner layer 26 on a sleeve is brought into contact with a toner layer 27 deposited on the surface of a control member will be described. FIG. 4 is a diagram illustrating the intermediate image holding belt. As shown in FIG. 4, a guide belt 51 made of a polyethyl terephthalate (PET) tape having a thickness of about 100 μm is provided at both ends in the width direction of the intermediate image holding belt so that both ends in the length direction overlap. Therefore, the thickness of the overlapping portion is about 200 μ
m.

When an intermediate image holding belt having such a guide belt is used to form an image, the intermediate image holding belt is rotated, and when an image is not formed, the overlapping portion is set below the head. The overlapping portion pushes the FPC which can move independently of the sleeve, so that the toner layer on the sleeve provided at an interval of 200 μm or less and the toner layer covering the opening on the FPC can be brought into contact.

In response to an external signal, toner images corresponding to yellow, magenta, cyan, and black are synthesized on the intermediate image holding belt. Next, when the belt is rotated by the belt driving roller, the overlapping portion located on the intermediate image holding belt where the toner image is not formed pushes the FPC of the head of each color toward the sleeve, and the FPC corresponding to each color is pressed. And the two layers of toner on the sleeve are successively brought into contact with each other.

During the contact, it is preferable that the toner image is not transferred onto the recording paper by the transfer means. This is because the contact may cause a mechanical shock and disturb the transfer.

Preferably, an electric field is formed between the transfer means and the belt so that the toner does not adhere to the transfer means. Therefore, for example, 300-2000V between both
Is applied. Furthermore, more preferably, for example, 500
Up to 20,000V, frequency 500-5000H
At z, an alternating current is applied so that the electric field strength and the direction of the electric field change. This makes it possible to vibrate various toners having different charge amounts and sizes, thereby making it difficult for the toner to move to the transfer unit side.

In addition, during contact with each head,
Preferably, a voltage is applied to the corresponding back electrode. This is because the toner powder can be efficiently collected on a belt having no toner image electrically. As the voltage to be applied,
It is about 500-2000V. Furthermore, as the applied voltage, a voltage application that forms an AC electric field whose electric field strength or direction changes over time is more preferable. This makes it easy to vibrate and collect various toners having different charge amounts and sizes.

Similarly, a voltage may be applied to the control electrode during the contact. Thereby, the toner accumulated on the surface of the FPC can be collected on the sleeve side. The applied voltage is about -300V to 300V. By applying a negative voltage, the toner charged to the opposite polarity can be collected.

Although the toner collected on the belt may be dropped by belt cleaning, a separate cleaning means may be provided. As cleaning means, for example,
It is preferable that a removable brush is provided on the downstream side in the belt movement direction of each head so that the brush and the belt come into contact with each other immediately after the toner is collected by contact. A brush that is charged with static electricity is particularly effective.

In this embodiment, the contact timing is performed during a predetermined period from the completion of one image forming operation to the start of the next image forming operation. The intermediate image holding belt may be rotated during a predetermined period from immediately after the power is turned on to when the image forming operation is started. Alternatively, further, after the paper jam occurs in the image forming apparatus, the intermediate image is formed during a predetermined period from the time when the operation of removing the jammed paper from within the image forming apparatus is completed to the time when the image forming operation is restarted. The rotation may be performed by rotating the holding belt.

Further, in this embodiment, the number of times of contact with one head in a predetermined time is one, but the number of times of contact may be increased by providing a large number of overlapping portions.

(Embodiment 2) Another embodiment of the present invention in which the toner layer on the sleeve and the toner layer deposited on the control member are brought into contact with each other will be described. In the present embodiment, F
By moving the FPC holding frame to which the PC is fixed, the PC is brought into contact with the toner layer on the sleeve.

FIG. 5 is a schematic view of a head according to the present embodiment, in which 61 is a sleeve, 62 is a frame of developer carrying means, 63 is an FPC, 64 is an FPC holding frame, and 65 is a contact means.

The contacting means 65 is for moving the FPC holding frame up and down by converting the rotational movement of a motor or the like into a vertical movement by a gear or the like, and bringing the FPC into contact with the toner layer on the sleeve. The amplitude of the vertical movement is approximately 200 μm or less in the embodiment.

As in the first embodiment, the timing of the contact is the same as that of the belt movement during a predetermined period from the completion of one image forming operation to the start of the next image forming operation. The operation may be performed while synchronizing the movement of the contacting means, or may be performed during a predetermined period from immediately after the power is turned on to the image forming apparatus until the image forming operation is started. Alternatively, after the paper jam occurs in the image forming apparatus, the operation is performed during a predetermined period from the time when the operation of removing the jammed paper from within the image forming apparatus is completed to the time when the image forming operation is restarted. Is also good.

Further, as in the first embodiment, it is preferable to apply a voltage to the corresponding back electrode during contact with each head. Further, a cleaning unit may be provided as in the first embodiment. Further, a voltage may be applied to the control electrode.

In this embodiment, the intermediate image holding belt is used as the image receiving means, but a recording paper may be used.

(Embodiment 3) Another embodiment of the present invention in which the toner layer on the sleeve and the toner layer deposited on the control member are brought into contact with each other will be described. In the present embodiment, the FPC and the toner layer on the sleeve are brought into contact by changing the thickness of the developer layer on the developer carrying means.

In the present embodiment, a two-component system composed of a toner and a magnetic carrier is used as a developer.

FIG. 6 is a schematic view of the periphery of the head according to the present embodiment. Reference numeral 71 denotes a sleeve that rotates at a speed of 20 to 400 mm / sec, reference numeral 72 denotes a fixed magnet, reference numeral 73 denotes a developer including a carrier and toner, and reference numeral 74 denotes an FPC. .

In this configuration, usually, during image formation, the fixed magnet located inside the sleeve is fixed at the position shown in FIG. 6A, and the developer does not come into contact with the FPC as shown in the figure. However, when the direction of the fixed magnet is changed as shown in FIG. 6B, the thickness of the developer can be changed, so that the developer can be brought into contact with the toner layer deposited on the FPC. Become.

As in the first and second embodiments, the contact is performed during a predetermined period from the completion of one image forming operation to the start of the next image forming operation.
The operation may be performed while synchronizing the movement of the belt and the movement of the fixed magnet, or may be performed during a predetermined period from immediately after the power is turned on to the image forming apparatus until the image forming operation is started. Alternatively, after the paper jam occurs in the image forming apparatus, the operation is performed during a predetermined period from the time when the operation of removing the jammed paper from within the image forming apparatus is completed to the time when the image forming operation is restarted. Is also good.

Also, as in the first embodiment, it is preferable to apply a voltage to the corresponding back electrode during contact with each head. Further, a cleaning unit may be provided as in the first embodiment. Further, a voltage may be applied to the control electrode.

In the present embodiment, either the intermediate image holding belt or the recording paper can be used as the image receiving means, as in the second embodiment.

In the present embodiment, the thickness of the developer is changed by changing the direction of the magnet. However, the present invention is not limited to this. For example, an electromagnet may be used to change the strength of the magnetic field. Can be varied.

[0054]

According to the developing method of the present invention, the toner adhered to cover the opening of the developer control member can be efficiently collected, so that a white spot occurs on the image formed on the recording paper. The image quality can be remarkably improved without performing.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a developer carrying unit.

FIG. 2 is a schematic diagram of a developer control unit.

FIG. 3 is an overall schematic diagram of an image forming apparatus.

FIG. 4 is a perspective view of an intermediate image holding belt.

FIG. 5 is a schematic diagram of a head according to the second embodiment.

6A and 6B are configuration diagrams of a sleeve according to the third embodiment, where FIG. 6A is a configuration diagram during image formation, and FIG. 6B is a configuration diagram during contact.

FIG. 7 is a schematic diagram of a conventional image forming apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 sleeve 2 toner regulating blade 3 toner scraping and supplying roller 4 toner 5 stirring means 6 frame 11 FPC 12 FPC holding frame 20 insulating member 21 opening 22 control electrode 23 guard electrode 24 resin 26 toner layer 27 toner layer 41 head portion 42 belt Driving roller 43 Ground roller 44 Intermediate image holding belt 45 Back electrode 45 46 Power supply for back electrode 51 Guide belt 61 Sleeve 62 Frame of developer carrying means 63 FPC 64 FPC holding frame 65 Contact means 71 Sleeve 72 Fixed magnet 73 Carrier and toner Developer consisting of 74 FPC

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiro Aizawa 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Akira Fukano 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Akira Ryuji 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (28)

[Claims] 1. A developer carrying means for carrying and transporting a charged developer, and a plurality of developer passing holes for passing the developer, wherein the developer carrying means is provided in accordance with an image signal from the outside. A method of forming an image using an image forming apparatus having at least a developer passing control unit for controlling the passage of a supplied developer and an image receiving unit on which the passed developer lands at least in this order via a gap. During the period in which the developer does not pass through the developer passage hole, the developer layer carried on the developer carrying means is deposited on the surface of the developer passage control means on the side of the developer carrying means. An image forming method, comprising a step of contacting an agent at least once. 2. The image forming apparatus according to claim 1, wherein the developer carrying means is rotating at least during the contacting step. 3. The method according to claim 1, wherein the step of contacting comprises changing a distance between the developer passage control means and the developer carrying means.
The image forming method as described in the above. 4. The image forming method according to claim 1, wherein the contacting step comprises changing at least the thickness of the developer layer on the developer carrying means facing the developer passage control means. 5. The image forming method according to claim 1, wherein the image receiving means is a recording sheet. 6. The image receiving device according to claim 1, wherein the image receiving device rotates and the developer image formed on the image receiving device is transferred onto a recording sheet provided in a transfer device provided in a moving direction of the image receiving device. Image forming method. 7. When an image forming operation is continuously performed on an image receiving unit, the contacting step is performed during a predetermined period from the completion of one image forming operation to the start of the next image forming operation. The image forming method according to claim 1, which is performed. 8. The image forming method according to claim 1, wherein the contacting step is performed during a predetermined period from immediately after the power of the image forming apparatus is turned on to when the image forming operation is started. 9. The contacting step is performed after the paper jam occurs in the image forming apparatus and after the operation of removing the jammed paper from the image forming apparatus is completed and the image forming operation is restarted. 2. The image forming method according to claim 1, which is performed during a predetermined period. 10. An image forming apparatus according to claim 1, further comprising: an electric field forming unit that faces the developer passage control unit via the image receiving unit and forms an electric field between the developer passage control unit and the developer passage control unit. 2. The image forming method according to claim 1, wherein an electrostatic field is formed between the electric field forming unit and the developer passage control unit so as to move toward the image receiving unit. 11. During the contacting step, between the developer carrying means and the developer passing control means such that the developer deposited on the surface of the developer passing control means moves toward the developer carrying means. 2. The image forming method according to claim 1, wherein an electrostatic field is formed. 12. The image forming method according to claim 1, wherein the shortest distances from the surface of the developer layer carried on the developer carrying member to the rows formed by the developer passage holes are all equal. 13. The image forming method according to claim 3, wherein the distance is changed by moving the developer passage control means. 14. The developer has magnetism, and has a magnetic field generating means capable of changing the intensity and / or direction of a magnetic field formed on the surface of the developer carrying means, so that the thickness of the developer layer varies. Item 5. The image forming method according to Item 4. 15. An electric field forming means which faces the developer passage control means via an image receiving means, and forms an electric field between the developer passage control means and the developer passage means, and the electric field forming means is provided during the contacting step. 2. The image forming method according to claim 1, further comprising the step of: moving the developer in opposition to the developer passage control means, and removing the developer moved onto the electric field forming means from a developer passage hole of the developer passage control means. Method. 16. The method according to claim 6, further comprising the step of rotating the image receiving means during the contacting step and removing the developer transferred onto the image receiving means from the developer passage hole of the developer passage control means. Image forming method. 17. The image forming method according to claim 6, wherein during the contacting step, the developer image formed on the image receiving means is not transferred onto a recording sheet. 18. An image forming apparatus according to claim 6, wherein during the contacting step, an electrostatic field is formed between said transfer means and said image receiving means so that the developer adhering to the transfer means moves to the image receiving means side. Method. 19. The image forming method according to claim 18, wherein the electric field formed between the transfer unit and the image receiving unit is an alternating electric field whose electric field intensity and / or direction changes with time. 20. The image forming method according to claim 10, wherein the electric field formed between the electric field forming means and the developer passage control means is an alternating electric field whose electric field intensity and / or direction changes with time. . 21. A developer carrying means for carrying and transporting a charged developer, and a plurality of developer passage holes for passing the developer, wherein the developer carrying means receives the developer in response to an image signal from the outside. The developer carried on the developer carrying means has at least a developer passing control means for controlling the passage of the supplied developer and an image receiving means on which the passed developer lands, with a gap therebetween at least in this order. An image forming apparatus comprising an abutting means for abutting a developer layer and a developer deposited on the surface of the developer passage control means. 22. The developing device according to claim 21, wherein the developer carrying means is rotatable at least during the contact. 23. The mechanism according to claim 21, wherein the contact means is a mechanism for displacing a distance between the developer passage control means and the developer carrying means.
The image forming apparatus as described in the above. 24. The image forming apparatus according to claim 21, wherein the contacting means is a mechanism for changing the thickness of the developer layer on the developer carrying means facing the developer passage control means. 25. The image forming apparatus according to claim 24, wherein the mechanism for changing the thickness is a magnetic field generating means capable of changing the intensity and / or the direction of a magnetic field formed on the surface of the developer carrying means for carrying the magnetic developer. apparatus. 26. The image receiving means is a recording sheet.
The image forming apparatus as described in the above. 27. The image forming apparatus according to claim 21, wherein said image receiving means rotates and transfers a developer image formed on said image receiving means onto a recording sheet by a transfer means provided in a moving direction of said image receiving means. apparatus. 28. The image forming apparatus according to claim 27, further comprising an electric field forming unit that faces the developer passage control unit via the image receiving unit and forms an electric field between the developer passage control unit and the developer passage control unit.