WO2018012266A1

WO2018012266A1 - Developing device

Info

Publication number: WO2018012266A1
Application number: PCT/JP2017/023419
Authority: WO
Inventors: 北山　邦彦
Original assignee: キヤノン株式会社
Priority date: 2016-07-15
Filing date: 2017-06-26
Publication date: 2018-01-18
Also published as: JP2018010252A; JP6800635B2

Abstract

This developing device (4) includes: an accommodation portion (45) for accommodating a developing fluid; a supply portion (45b) for supplying the developing fluid in the accommodation portion (45) to a developer carrier (41); and a replenishing portion (47) for replenishing the accommodation portion (45) with the developing fluid. The accommodation portion (45) is provided with a wall portion (46) partitioning the accommodation portion into a first region (A1) containing the replenishing portion (47) and a second region (A2) containing the supply portion (45b). A communication portion is provided under the wall portion (46) so as to establish communication between the first region (A1) and the second region (A2), thereby allowing the developing fluid replenished in the first region (A1) to move into the second region (A2) through the communication portion.

Description

Development device

The present invention relates to a developing device used in an image forming apparatus such as an electrophotographic system or an electrostatic recording system.

Conventionally, a developing device of a so-called wet development system (liquid development system) has been used to develop an electrostatic latent image formed on an image carrier using a developer in which coloring components (toner particles) are dispersed in a liquid carrier. Are known. Patent Document 1 discloses a developing device provided with a pre-chamber formed open at the upper side, and a developing roller disposed opposite to the pre-chamber. The developing solution filled in the pre-chamber is scooped up and coated on the roller surface as the developing roller rotates, and is used for development through a concentration process of toner components and a removal process of an excess developer.

JP 2013-222208 A

In the developing device described in Patent Document 1, since the developing solution stored in the pre-chamber is consumed as the developing roller rotates, a new developing solution is sent to the pre-chamber by a pump. . However, when the liquid level in the chamber largely fluctuates due to the inflow of the developing solution, the amount of the developing solution coated on the developing roller becomes nonuniform, which may cause unevenness in the density of the output image.

Therefore, an object of the present invention is to provide a developing device capable of contributing to the improvement of the image quality by stabilizing the amount of the developer carried on the developer carrier.

A developing device according to an aspect of the present invention is a developing device that develops an electrostatic latent image on an image carrier using a developer, which is a rotatable developer carrier that carries a developer, and A storage unit for storing a developer to be supplied to the developer carrier, and a supply for supplying the developer in the storage unit to the developer carrier, provided at a position facing the developer carrier on the container. And the downstream side of the supply unit in the rotational direction of the developer carrier, and on the upstream side of the position on the image carrier where the electrostatic latent image is developed, the developer carrier is provided on the developer carrier A regulating member for regulating the amount of developer, a replenishing unit provided in the accommodating unit for replenishing the accommodating unit with the developing solution, a first region including the replenishing unit in the accommodating unit, and the supply unit A wall separating the two regions, provided below the wall in the vertical direction, Serial first region and the second region and a communication portion for communicating.

The developing device according to the present invention can contribute to the improvement of the image quality by stabilizing the amount of the developer carried on the developer carrier.

FIG. 2 is a cross-sectional view of the developing device according to the first embodiment as viewed from the thrust direction. FIG. 2 is a cross-sectional view of the developing device according to the first embodiment as viewed from the back side. FIG. 2 is an enlarged cross-sectional view of the main part of the developing device according to the first embodiment. FIG. 2 is an enlarged cross-sectional view of the main part of the developing device according to the first embodiment. FIG. 1 is a perspective view of a developing device according to a first embodiment. Sectional drawing which looked at the developing device which does not contain the structure for pressure adjustment from the thrust direction. Sectional drawing of the supply tray which concerns on a 1st Example. FIG. 7 is a cross-sectional view of the developing device according to the second embodiment as viewed in the width direction. FIG. 7 is a cross-sectional view of the developing device according to the second embodiment as viewed from the back side. The top view of the supply tray which concerns on a 2nd Example. FIG. 1 is a schematic view showing a configuration of an image forming apparatus. FIG. 2 is a schematic view showing a developing device and a supply configuration of a developer. Sectional drawing which looked at the developing device for comparison from the width direction. Sectional drawing which looked at the developing device for comparison from the front.

Hereinafter, a developing device and an image forming apparatus according to the present disclosure will be described with reference to the drawings. The image forming apparatus is, for example, a printer, a copier, a facsimile machine, and a multifunction machine, and forms an image on a recording material based on image information input from an external PC and image information read from an original. The recording material includes a sheet such as a sheet and an envelope, a plastic film such as an overhead projector sheet (OHT), and a cloth.

As shown in FIG. 11, the image forming apparatus 100 includes an electrophotographic image forming unit having a photosensitive drum 1 which is a drum type photosensitive member. Although a single image forming unit is illustrated, the present technology may be applied to an image forming apparatus (for example, a full color laser beam printer of a tandem intermediate transfer method) including a plurality of image forming units.

Around the photosensitive drum 1, a charging device 2, an exposure device 3, a developing device 4, a transfer roller 5 and a cleaning device 6 are disposed in this order along the rotational direction of the photosensitive drum 1. When the image forming operation is started, the surface of the photosensitive drum 1 is uniformly charged by the charging device 2 as the photosensitive drum 1 rotates. The exposure device 3 modulates and outputs a laser beam based on image information, scans the photosensitive drum 1 and forms an electrostatic latent image on the drum surface. The developing device 4 is a wet developing device using a developer in which toner particles are dispersed in a liquid carrier (carrier liquid), and supplies the developer carried on the developing roller 41 to the photosensitive drum 1 to thereby form an electrostatic latent image. The toner image is visualized (developed).

Along with the progress of the image forming operation, the recording material 101 is fed from a sheet feeding portion (not shown) and conveyed toward a transfer nip portion formed by the transfer roller 5 in pressure contact with the photosensitive drum 1. The toner image carried on the photosensitive drum 1 is transferred to the recording material 101 by the pressure in the transfer nip portion and the bias voltage (electrostatic load bias) applied to the transfer roller 5. For example, heat and pressure are applied to the recording material 101 to which the toner image has been transferred in a fixing device (not shown) to form a fixed image. The adhered material such as the developing solution remaining on the photosensitive drum 1 without being transferred to the recording material 101 is removed or collected by the cleaning device 6.

Next, the configuration for supplying the developing solution to the developing device 4 will be described. Inside the image forming apparatus 100, as shown in FIG. 12, a developer tank 71 connected to the developing device 4 via a supply pump 75 and a recovery pump 76 is disposed. The developer stored in the developer tank 71 is supplied (supplemented) by the supply pump 75 to the developing device 4 through the supply pipe 53. Further, the developer recovered from the developing device 4 through the recovery pipe 52 is returned to the developer tank 71 by the recovery pump 76.

To the developer tank 71 is attached a density sensor 72 capable of detecting toner concentration (for example, weight ratio of toner component to carrier liquid), and a toner replenishing portion 73 and a carrier replenishing portion 74 capable of replenishing toner and carrier, respectively. Is connected. A control unit (not shown) that controls the operation of the image forming apparatus 100 appropriately replenishes toner or carrier from the toner replenishment unit 73 and the carrier replenishment unit 74 based on a detection signal from the density sensor 72. The supplied developer component (toner or carrier liquid) and the developer recovered through the recovery pump 76 are agitated and homogenized in the developer tank 71.

As described above, the developing device 4 is developed by the developer tank 71, which is a reservoir for storing the developer, the supply pump 75 and the recovery pump 76, the density sensor 72, the toner replenishing portion 73 and the carrier replenishing portion 74. A supply mechanism 70 for supplying a liquid is configured. The developer is controlled so that the toner concentration becomes constant while circulating between the developing device 4 and the supply mechanism 70.

The consumption speed of the components of the developer may differ between the toner and the carrier liquid depending on the conditions of image formation. The carrier liquid is consumed when the developing roller 41 and the photosensitive drum 1 contact and rotate regardless of the image density. On the other hand, the toner consumes a larger amount as the image density is higher and the size of the output image is larger. Accordingly, the toner concentration of the developer recovered from the developing device 4 changes depending on conditions such as the density of the output image and the size of the image. The control unit obtains the consumption amounts of the toner and the carrier liquid from the measurement results of the toner concentration by the density sensor 72, and determines the replenishment amounts of the toner and the carrier liquid so as to compensate the consumption amounts.

Next, the configuration and operation of the developing device 4 according to the first embodiment will be described. As shown in FIG. 1, the developing device 4 includes a casing 40, a developing roller 41, a squeeze roller 42, a cleaning roller 43, an electrode segment 44, and a supply tray 45. The developing roller 41, the squeeze roller 42, and the cleaning roller 43 are disposed in parallel to one another. Hereinafter, the axial direction (axial direction) of these rollers is referred to as the thrust direction of the developing device 4, and the side facing the photosensitive drum 1 (right side in the figure) as viewed from the thrust direction is the front side, and the opposite side is the back side. I assume.

The casing 40 forming the casing of the developing device 4 is formed in a rectangular parallelepiped shape extending in the thrust direction, and is formed by opening a part on the front side over substantially the entire length in the thrust direction. The developing roller 41, which is a developer carrier, is disposed in the opening of the casing 40 so as to face the photosensitive drum 1, and a developing nip G2 is formed between the developing roller 41 and the photosensitive drum 1 as a developing unit. The developing roller 41 can rotate in a direction along with the photosensitive drum 1. The developer carrier is not limited to the roller member, and may be, for example, a sleeve-like (cylindrical) or belt-like member.

The supply tray 45 for supplying the developing solution to the developing roller 41 is a storage portion (a developing solution storage portion) disposed on the back side of the developing roller 41. In addition, a storage part shall refer to the part holding a developing solution among arbitrary members which can hold a liquid not only in tray shape (dish shape) but in an upper surface. The supply tray 45 is formed of a flexible sheet 45b disposed on the front side and a back side wall 45c erected on the back side with respect to a bottom 45a extending in a substantially horizontal direction. Further, as shown in FIG. 2, both ends of the supply tray 45 in the thrust direction are closed by a casing 40, and a supply port 47, which is a supply section to which a developing solution is supplied, is formed on one wall surface. 2 is a cross-sectional view of the developing device 4 at the position of the broken line shown in FIG.

The flexible sheet 45b has an appropriate hardness capable of holding the developing solution while maintaining the state in contact with the developing roller 41. For example, a PET resin (polyethylene terephthalate) or a urethane resin can be used. . The sheet 45 b is disposed such that the tray upper side is opened, and forms a supply unit that supplies the developing solution to the developing roller 41. Further, the back side wall 45c, which is a discharge unit, is disposed so that the back side is opened so that the developer can be discharged when the liquid level in the tray becomes a predetermined height or more. As described later, the supply tray 45 is divided by the partition plate 46 into a first area A1 and a second area A2.

The electrode segment 44 is disposed above the supply tray 45, and faces the developing roller 41 with a gap G1 having a predetermined width interposed therebetween. The width of the gap G1 is set so that the amount of developing solution to be scooped up by the developing roller 41 becomes a target value. Therefore, the electrode segment 44 functions as a regulating member (regulating portion capable of adjusting the amount of liquid) for regulating the amount of the developing solution carried by the developing roller 41. Further, a potential difference is formed between the electrode segment 44 and the developing roller 41 so as to bias the toner toward the developing roller 41 in the gap G1 by a power supply (not shown).

A squeeze roller 42, which is a removing member for removing the excess developer, is disposed downstream of the electrode segment 44, and a cleaning roller 43, which is a cleaning member, is disposed downstream of the developing nip G2. The squeeze roller 42 and the cleaning roller 43 rotate in a direction along with the developing roller 41.

The operation of the developing device 4 and the flow path of the developer will be described below. The developer sent from the supply pump 75 (see FIG. 12) is supplied to the supply tray 45 through the supply port 47 which is the opening of the supply pipe 53. The developer held in the supply tray 45 is drawn up to the gap G1 as the developing roller 41 rotates, and toner particles are attracted to the surface of the developing roller 41 according to the potential difference formed by the electrode segment 44.

When the developer reaches the nip portion between the squeeze roller 42 and the developing roller 41, the toner held on the surface of the developing roller 41 and a part of the carrier liquid are pushed back. The upper surface 44 a of the electrode segment 44 is inclined downward from the front side to the back side, and forms a flow path for discharging the developer pushed back by the squeeze roller 42 through the upper side of the supply tray 45. doing. The developer dropped from the upper surface 44 a of the electrode segment 44 to the bottom 49 of the casing 40 is recovered to the developer tank 71 via the recovery port 51.

When the developer having passed through the squeeze roller 42 reaches the developing nip G2, the toner is electrophoresed according to the potential difference between the bias voltage applied to the developing roller 41 and the surface potential of the photosensitive drum 1. Thus, toner adheres to the surface of the drum according to the potential distribution of the electrostatic latent image, and a toner image is formed on the photosensitive drum 1. Further, part of the carrier liquid carried on the developing roller 41 adheres to the photosensitive drum 1 in the process of separating the developing roller 41 and the photosensitive drum 1 on the downstream side of the developing nip portion G2.

The toner and carrier liquid remaining on the developing roller 41 without being moved to the photosensitive drum 1 at the developing nip G2 are collected by the cleaning roller 43 using electrostatic force. The developer adhering to the cleaning roller 43 is scraped off by the cleaning blade 50 in contact with the cleaning roller 43 and falls to the bottom 49 of the casing 40.

Here, the replenishment amount of the developing solution by the supply pump 75 is set to be larger than the amount of liquid which is scooped up by the developing roller 41. For this reason, while a state in which a predetermined amount or more of the developing solution is held in the supply tray 45 is maintained, the developing solution over the back side wall 45 c which is the discharge portion drops to the bottom portion 49 of the casing 40 as a surplus. .

The developer discharged through the above-described plurality of paths is collected through the collection port 51 formed in the bottom 49 of the casing 40. The developer flowing into the recovery pipe 52 via the recovery port 51 is returned to the developer tank 71 via the filter (not shown) by the recovery pump 76, and then the toner concentration is adjusted and supplied to the developing device 4 again. Be done.

Next, the flow direction of the developing solution in the supply tray 45 and the waving of the liquid surface will be described using the comparative developing device 4Z shown in FIG. 13 and FIG. 14 is a cross-sectional view of the developing device 4Z at the position of the broken line shown in FIG. The developing device 4 Z is different from the developing device 4 according to the present embodiment in that the partition plate 46 is not disposed in the supply tray 45, and the other configuration is common to the developing device 4. Hereinafter, the same reference numerals are given to the elements common to the above-mentioned developing device 4 and the description will be omitted.

As shown in FIGS. 13 and 14, the developing device 4Z is provided with a replenishment port 47 formed at the end of the supply tray 45 in the thrust direction, as in the present embodiment. Accordingly, the developer fed from the supply pump 75 flows into the supply tray 45 along the inflow direction V1 substantially parallel to the thrust direction.

Here, for example, when the rotational speeds of the photosensitive drum 1 and the developing roller 41 are increased in order to improve the speed of image output, the replenishment amount per unit time of the developing solution to the supply tray 45 is increased accordingly. You will need to Further, in order to miniaturize the apparatus and prevent the developer from staying for a long period of time, it is preferable to set the tube diameter of the supply pipe 53 and the supply tray 45 smaller. Thus, the apparatus can be miniaturized, and appropriate replacement of the developer can be expected.

However, as the inflow rate of the developer flowing into the supply tray 45 increases, the waving of the developer in the supply tray 45 tends to increase. In addition, when the supply tray 45 is small, the inflow speed of the developing solution becomes relatively large with respect to the capacity of the supply tray 45, so that the corrugation easily occurs. Furthermore, when the supply tray 45 is small (shallow), the height of the supply port 47 is close to the upper end position of the back side wall 45c that defines the average liquid level of the developer, which causes the increase of the waving. In the present embodiment, the flow velocity of the developer at the position of the supply port 47 was approximately 1 to 3 m / sec.

When the liquid level in the supply tray 45 fluctuates due to such a wave, the amount of scooping of the developer by the developing roller 41 temporally or spatially fluctuates, which may lead to uneven density of the output image. That is, when the developing roller 41 rotates in a state where the liquid level in the thrust direction is not stable, the carried amount (coating amount) of the developer is insufficient in a part of the thrust direction, and a part of the output image becomes thin. It is conceivable. For example, in the case of the present embodiment, when air bubbles intrude into the gap G1 between the developing roller 41 and the electrode segment 44 due to the fluctuation of the liquid surface, the coating amount may become uneven.

Therefore, in the present embodiment, the partition plate 46 is disposed as a wall portion (partition portion) that divides the inside of the supply tray 45 which is the holding area of the developer. As shown in FIG. 3, the partition plate 46 is disposed on the upper side of the supply tray 45 with a gap 48 having a predetermined width from the bottom surface of the tray, that is, the top surface of the bottom 45a. Thus, the inside of the supply tray 45 is divided into a first area A1 in which the supply port 47 and the discharge section (45c) are disposed, and a second area A2 in which the supply section (45b) is disposed. The first area A <b> 1 and the second area A <b> 2 communicate with each other through a gap 48 which is a communicating portion.

The partition plate 46 is a plate-like member disposed along the thrust direction, and extends upward from the upper end of the back side wall 45c that defines the height of the liquid surface S1 in the first region A1. Further, the partition plate 46 extends downward from the lower surface 44 b of the electrode segment 44 as a covering portion covering the supply tray 45 as viewed from above.

The electrode segment 44 is an example of a cover, and a partition plate may extend downward from a member covering at least a part of the supply tray 45. Further, even in the configuration in which the supply tray 45 is opened upward, the partition plate 46 may extend above the back side wall 45 c. The partition plate 46 may be supported or integrally formed on the electrode segment 44 or may be supported by the supply tray 45 as long as the function of the gap 48 is not impaired.

As shown in FIG. 6, the developer supplied to the supply tray 45 through the supply port 47 first flows into the first area A1, and then passes through the lower gap 48 in the vertical direction of the partition plate 46 and then the second Move to the area. At this time, even if the liquid surface S1 in the first region A1 is corrugated, the partition plate 46 prevents the wave from propagating directly to the liquid surface S2 in the second region A2 (hence the waves are generated) See Figure 3). Thereby, the fluctuation of the liquid surface in the second area A2 is reduced as compared with the case where the partition plate 46 is not provided, and the coating amount of the developing solution by the developing roller 41 can be stabilized.

Further, while the supply port 47 is disposed at the end in the thrust direction, the partition plate 46 is disposed along the thrust direction. That is, the supply port 47 and the partition plate 46 are disposed such that the inflow direction V1 of the developing solution in the first area A1 and the moving direction V2 of the developing solution from the first area A1 to the second area A2 are different. . For this reason, the flow velocity of the developer passing through the gap 48 becomes smaller as compared with the configuration in which the developer replenished to the supply tray 45 directly flows toward the second area A2, and the liquid level in the second area A2 decreases. Fluctuations can be further reduced.

Here, an upper communicating portion 54 which communicates the upper portions of the first area A1 and the second area A2 is provided in the upper portion of the partition plate 46. As shown in FIG. 2, the upper communication portions 54 are disposed at both ends of the partition plate 46 in the thrust direction. As shown in FIGS. 4 and 5, the upper communication portion 54 is formed by a notch provided at the upper end of the partition plate 46 and the lower surface 44 b of the electrode segment 44.

As shown in FIG. 7, when the partition plate 460 not provided with the upper communication portion is disposed, the upper portion of the second region A2 is airtightly surrounded by the liquid surface S2 and the electrode segment 44 and the partition plate 460. Closed space. That is, when the liquid surface S2 reaches the height of the lower end portion 44c of the electrode segment 44 when the developer is supplied to the supply tray 45 by starting the circulation of the developer, such as when installing the image forming apparatus 100, The space above the liquid level S2 is clogged.

In this case, even if the liquid surface S2 is lower than the liquid surface S1 of the first region A1, the pressure in the upper portion of the second region A2 prevents the liquid surface S2 from rising. Accordingly, in the second region A2, the liquid surface S2 and the lower end 44c of the electrode segment 44 are in a close state, and air bubbles intrude into the open portion 45d even if the liquid surface S2 slightly fluctuates. It is thought that the coating amount uniformity is lost.

On the other hand, in the present embodiment, since the upper communicating portion 54 is disposed as a pressure adjusting portion that adjusts the pressure difference (air pressure difference) between the first area A1 and the second area A2, the height of the liquid surface S2 of the second area A2 It can approach the height of liquid level S1 of the 1st field A1. Therefore, air bubbles are less likely to enter the open portion 45d between the lower end 44c of the electrode segment 44 and the sheet 45b where the raising to the gap G1 is performed, and the uniformity of the coating amount can be improved.

The pressure adjustment unit may be provided at a different position as long as it is above at least the upper end position of the back side wall 45 c which is the discharge unit. For example, the end of the supply tray 45 in the thrust direction or the electrode segment 44 may be provided with an opening shape for communicating the upper portion of the second area A2 with the outside of the supply tray 45. Further, the position and the number of installation other than the height of the upper communication portion 54 are arbitrary, and for example, one may be disposed at the central portion in the thrust direction.

In addition, if the shape of the wall section divides the supply tray 45 into the upstream area (first area A1) and the downstream area (second area A2) in the developer flow direction, the present embodiment It is not limited to the one described in the example. For example, it is not limited to a flat plate shape, and may have a V-shaped member in a cross sectional view or a shape bent in a plan view. Further, the communicating portion for communicating the first region A1 and the second region A2 may be formed in a part in the thrust direction (including the case where the communicating portion has a tubular shape), instead of the gap 48. However, in this embodiment, since the gap 48 is formed over substantially the same length as the developing roller 41 in the thrust direction (see FIGS. 2 and 6), the cross-sectional area of the communicating portion can be increased without increasing the gap width. Therefore, the flow velocity of the developing solution toward the second area A2 can be suppressed.

Next, a developing device 4B according to a second embodiment will be described with reference to FIGS. The developing device 4B according to the present embodiment is different from the first embodiment in that the arrangement of the supply port 56 and the rectifying plate 57 disposed in the first area A1 of the supply tray 45 are provided. The other elements common to the first embodiment are denoted by the same reference numerals and the description thereof will be omitted.

As shown in FIG. 8, the developing device 4B according to the present embodiment is, like the developing device 4 according to the first embodiment, a partition plate which divides the supply tray 45 into the first area A1 and the second area A2. 46, which is the wall. However, as shown in FIG. 9, the supply port 56 according to the present embodiment is disposed at the central portion of the supply tray 45 in the thrust direction, and is formed in the bottom portion 45a of the tray. The supply pipe 55 is connected to the supply port 56 via the lower side of the supply tray 45. However, FIG. 9 is a cross-sectional view of the developing device 4B at the position of the broken line shown in FIG.

Further, the straightening vane 57 provided as a guiding portion for guiding the developing solution is an opposing member disposed to face the supply port 56. As shown in FIG. 10, the current plate 57 is disposed so as to cover the supply port 56 as viewed from above.

With such a configuration, the developer sent from the supply pump 75 flows into the first area A1 along the upward flow direction V1 and collides with the straightening plate 57 to be distributed on both sides in the thrust direction. (V4, V4). Then, the developer spread in the thrust direction moves to the second area via the communicating portion formed as a gap between the partition plate 46 and the bottom 45 a of the supply tray 45. The developer moved to the second area A2 is scooped up to the gap G1 as the developing roller 41 rotates, and is used for development.

As described above, also in the present embodiment, since the supply tray 45 is partitioned by the partition plate 46 which is a wall portion, the fluctuation of the liquid level in the second region A2 is reduced to develop the developing roller as in the first embodiment. The coating amount for 41 can be stabilized.

Further, in the present embodiment, the developer flowing into the first area A1 through the supply port 56 is moved in the flow direction V4 of the developer in the first area A1, and the movement direction from the first area A1 to the second area A2. It is configured to be guided by the current plate 57 so as to be different from V2. Therefore, even when the inflow velocity of the developing solution is relatively high, it is possible to reduce the momentum of the developing solution and to disperse the developing solution in the thrust direction by the rectifying plate 57. Therefore, it is possible to prevent the developer flowing into the first area A1 from flowing directly toward the second area A2, and to effectively suppress the fluctuation of the liquid level in the second area A2.

The shape and arrangement of the guide portion may be different from that of the flow control plate 57 as long as the developer flowing into the first area A1 can be appropriately guided. For example, in the case where the replenishment port 56 is provided at a location other than the bottom of the supply tray 45, it is preferable to dispose the replenishment port 56 so as to face the replenishment port 56 at a position and posture according to the inflow direction of the developer. In addition to the plate-like member, for example, a guide portion formed in a pile shape or a net shape may be disposed in the first region A1 to increase the flow resistance of the developer and to suppress the flow speed.

The present developing device can be used in an image forming apparatus such as a copying machine or a laser beam printer using an electrophotographic method or an electrostatic recording method.

4, 4B: developing device: 41: developer carrier (developing roller): 42: removing member (squeeze roller): 44: regulating member (electrode segment): 45: housing portion (supply tray): 45a: bottom surface (bottom portion) / / 45b ... supply section (sheet) / 45c ... discharge section (back side wall) / 46 ... wall section (partition plate) / 47, 56 ... replenishment section (supply port) / 48 ... communication section (gap) / 54 ... pressure Adjustment section (upper communication section) / A1 ... first area / A2 ... second area

Claims

A developing device for developing an electrostatic latent image on an image carrier using a developing solution, comprising:
A rotatable developer carrier for carrying a developer;
A storage unit for storing a developer to be supplied to the developer carrier;
A supply unit provided at a position facing the developer carrier in the storage unit, for supplying the developer in the storage unit to the developer carrier;
The developer carrier is provided on the downstream side of the supply unit in the rotational direction of the developer carrier and on the upstream side of the position on the image carrier on which the electrostatic latent image is developed. A regulating member that regulates the quantity;
A replenishing unit provided in the accommodating unit for replenishing the accommodating unit with a developer;
A wall section that partitions a first area including the supply section in the storage section and a second area including the supply section;
A communication portion provided below the wall portion in the vertical direction and in which the first region and the second region communicate with each other;
Developing device.
The storage unit is provided with a discharge unit that discharges the developing solution in the first area when the liquid surface of the developing solution in the first area reaches a predetermined height or more.
The wall extends at least above the predetermined height,
The developing device according to claim 1.
The restricting member covers at least a part of the accommodating portion as viewed from above;
The wall portion extends downward from the regulating member to form the communication portion with the bottom surface of the housing portion.
The developing device according to claim 1.
And a removing member disposed downstream of the regulating member in the rotational direction of the developer carrier and removing excess developer from the developer carrier.
The restriction member is disposed to cover the container together with the developer carrier, and forms a flow path for discharging the developer removed by the removing member through the upper side of the container.
The developing device according to claim 3.
The second region is a space formed by the housing portion, the regulation member, the wall portion, and the developer carrier.
In at least one of the housing portion, the regulating member, and the wall portion, a pressure adjusting portion is provided that communicates the second region with the space outside the second region, and adjusts the air pressure in the second region. Provided
The developing device according to any one of claims 1 to 4.
The pressure adjusting unit is provided on the wall portion.
The developing device according to claim 5.
The inflow direction of the developing solution flowing into the first area via the replenishing unit is different from the moving direction of the developing solution moving from the first area to the second area via the communication unit. A refill and the wall are arranged,
The developing device according to any one of claims 1 to 6.
The developer carrier comprises a roller member,
The wall extends in the axial direction of the developer carrier;
The replenishment unit is disposed at an end of the housing in the axial direction.
The developing device according to any one of claims 1 to 7.
The developer carrier comprises a roller member,
The wall extends in the axial direction of the developer carrier;
The supply unit is disposed at a central portion of the storage unit in the axial direction;
The first region of the storage portion is provided with a guide portion for guiding the developer flowing in via the replenishing portion and distributing it along the axial direction.
The developing device according to any one of claims 1 to 7.
The supply unit is disposed at the bottom of the storage unit;
The guide portion is an opposing member that faces the supply portion on the lower surface,
The developing device according to claim 9.