JP5703866B2 - Powder supply mechanism, developing device, process unit, and image forming apparatus - Google Patents

Description

  The present invention relates to a powder replenishment mechanism applicable to replenishment of powder (toner) in an image forming apparatus such as an electrophotographic copying machine, printer, facsimile, and the like, and toner as a developer is replenished by this powder replenishment mechanism The present invention relates to a developing device, a process unit, and an image forming apparatus.

Here, the process unit is, for example,
1) A charging unit, a developer carrier or a cleaning unit and an image carrier are integrated into a unit, and the unit body is detachable from the main body of the image forming apparatus.
2) At least one of a charging unit, a developer carrier, and a cleaning unit and an image carrier are integrated into a unit so as to be detachable from the main body of the image forming apparatus.
3) A developer carrying member and an image carrying member that are integrated into a single unit and detachable from the image forming apparatus main body.
Any of the above 1) to 3) may be used.

  A conventional electrophotographic image forming apparatus exposes a uniformly charged surface of an image carrier in accordance with image information by a laser as an exposure unit, thereby providing a static image corresponding to the image information on the surface of the image carrier. An electrostatic latent image is formed. Then, a toner as a developer is supplied to the surface of the image carrier by a developing roller of a developing unit so that the electrostatic latent image is visualized, that is, developed. A predetermined amount of toner is stored inside the developing means in order to realize stable developability, and this toner is agitated by an agitating member in order to make the charge amount uniform. Since the toner inside the developing means decreases as the development proceeds, when the toner amount falls to a predetermined amount, this is detected by a toner remaining amount detecting means such as an optical sensor or a piezoelectric sensor, and new toner is developed from the toner container. The means is replenished (see Patent Document 1). Also, instead of using the piezoelectric sensor, the accumulated toner consumption is estimated from the usage status such as the printing ratio of the developing means, and this is integrated by the integrating means, and it is determined that the remaining amount of toner in the developing means falls below a predetermined amount. Sometimes toner is replenished (see Patent Document 2).

  The invention of Patent Document 1 requires a sensor for detecting the remaining amount of toner and its control system, and there is a problem that the number of parts increases and the cost increases. In the invention of Patent Document 2 in which the remaining toner amount is determined by estimating the accumulated toner consumption amount without using a sensor, the error of the accumulating unit may be accumulated to cause a deviation from the actual remaining toner amount. There is a possibility that the toner replenishment timing will be delayed and toner shortage may occur, or excessive supply exceeding the toner buffer amount of the developing unit may occur.

  An object of the present invention is to maintain an appropriate amount of powder (toner) remaining in a container containing powder (toner) using only mechanical parts without using a sensor or an integrating means.

In order to solve the above problems, the present inventions (1) to (16) are configured as follows.
(1) A container for storing powder, a powder supply port arranged at the upper part of the container, and a powder placed on the powder surface in the container, and accompanying the increase or decrease of the powder in the container A powder supply mechanism comprising: an elevating member that moves up and down in response to the vertical movement of the surface; and a control member that controls increase and decrease in the opening area of the powder supply port in response to the up and down movement of the elevating member.
According to the first aspect of the present invention, the elevating member that moves up and down in response to the vertical movement of the powder surface accompanying the increase or decrease of the powder in the container fulfills the function of the conventional sensor. The number of parts can be reduced and the cost can be reduced, and since there is no method for estimating the remaining amount of powder from the cumulative consumption of powder, there is no possibility of delay in powder replenishment or excessive supply due to integration error.

(2) The elevating member is composed of a base portion placed on the powder surface, the control member is composed of a rod portion capable of entering the powder supply port, and the rod portion is integrated with the base portion. The powder supply mechanism according to the first aspect of the present invention.
According to the second aspect, the number of parts and the cost of the powder supply mechanism can be further reduced by integrating the elevating member and the control member.

(3) The powder of the invention 2 wherein the container constitutes a part of a powder consumption apparatus and the powder supply port constitutes a part of a powder replenishing apparatus that is detachable from the container of the powder consumption apparatus. Body supply mechanism.
According to the third aspect of the present invention, the present invention can be applied even when the container for storing the powder of the powder consumption device and the powder supply port of the powder supply device are separable.

(4) When the powder supply port is disposed downward and the base portion is raised, the rod portion enters the powder supply port to reduce the powder supply amount, and when the base portion is lowered, the rod portion The powder supply mechanism according to invention 2 or 3, wherein the powder supply amount is increased by exiting from the powder supply port.
According to the fourth aspect of the invention, since the base portion functions as a conventional sensor, the number of parts of the powder supply mechanism can be reduced and the cost can be reduced by omitting the sensor, and the powder can be supplied by raising and lowering the base portion. Since the amount of powder supply is controlled to increase or decrease by the entry / exit of the rod portion with respect to the mouth, there is no possibility of delay in supplying powder or excessive supply.

(5) The powder supply mechanism according to invention 4, wherein the tip portion of the rod portion that can enter the powder supply port is gradually narrowed from the base portion side toward the tip side.
According to the fifth aspect of the present invention, since the opening area of the powder supply port can be continuously changed corresponding to the vertical movement of the powder surface, the amount of powder supply can be adjusted corresponding to the height of the powder surface. It can be controlled appropriately.

(6) The powder supply mechanism according to any one of the inventions 2 to 5, wherein a plurality of the powder supply port and the rod portion are provided.
According to this invention 6, the weight of the powder acting on the rod portion can be dispersed, and the control pattern of the opening area of the powder supply port by each rod portion can be individually set. Supply control becomes possible.

(7) The powder supply mechanism of the invention 6 in which the heights of the plurality of rod portions are made different.
According to the seventh aspect of the present invention, the powder supply amount can be appropriately controlled in accordance with the height of the powder surface.

(8) The powder supply mechanism according to any one of the inventions 2 to 7, wherein at least a part of the base portion is made of a foamed resin.
According to the present invention 8, a base portion having a specific gravity smaller than that of the powder can be realized easily and at low cost.

(9) The powder supply mechanism according to any one of the inventions 2 to 8, wherein the base portion has a hollow portion.
According to the ninth aspect of the present invention, since the weight of the base portion relative to the apparent volume (bulk volume) can be reduced by reducing the material of the base portion, the base portion that reliably floats on the powder surface even with an ordinary resin material Can be realized.

(10) The powder supply mechanism according to any one of inventions 2 to 9, wherein a through-hole penetrating in the vertical direction is formed in the base portion.
According to the tenth aspect of the present invention, the powder that has fallen onto the base portion falls downward from the through hole, so that the base portion can be prevented from being buried in the powder.

(11) The powder supply mechanism according to invention 10, wherein a plurality of the through holes are formed and a rib having a substantially triangular cross-sectional shape having an acute apex portion and a flat bottom portion is formed between the through holes.
According to this invention 11, it becomes difficult for the powder to be deposited on the base portion by the rib having the acute angle top portion, and the contact area of the base portion to the powder surface can be secured by the flat bottom portion of the rib, The base portion can easily float on the powder surface.

(12) According to the invention 3, wherein the base part and the rod part are separable, the base part is disposed on the container side of the powder consumption apparatus, and the rod part is disposed on the powder supply apparatus side. Powder supply mechanism.
According to the twelfth aspect of the invention, since the lid member for closing the powder supply port on the powder replenishing device side can also be used as the rod portion, the number of parts can be reduced by omitting the lid member, and the powder replenishing device. It is possible to prevent leakage and scattering of the powder and to improve the mountability of the powder replenishing device to the powder consumption device.

(13) When the powder supply device is attached to the powder consumption device, the rod portion on the powder supply device side is connected to the base portion on the powder consumption device side by an uneven fitting structure. The powder supply mechanism according to the invention 12 described above.
According to the thirteenth aspect of the present invention, since the rod portion can be easily connected to the base portion by the concave-convex fitting structure, it is possible to improve the mountability of the powder replenishing device to the powder consumption device.

(14) A developing device comprising the powder supply mechanism according to any one of Inventions 1 to 13 for supplying a developer.
According to the fourteenth aspect, by omitting the sensor for detecting the remaining amount of the developer, it is possible to reduce the number of parts of the developing device and reduce the cost.

(15) A process unit including the powder supply mechanism according to any one of 1 to 13 for supplying a developer.
According to the fifteenth aspect, by omitting the sensor for detecting the remaining amount of developer, the number of parts of the process unit can be reduced and the cost can be reduced.

(16) An image forming apparatus comprising the powder supply mechanism of the invention 3 for supplying a developer, wherein the powder is a developer, the powder consuming device is a developing device, and the powder replenishing device is a developer replenishing device. .
According to the sixteenth aspect of the present invention, in the developer replenishment type developing device, the number of parts of the developing device can be reduced and the cost can be reduced by omitting the sensor for detecting the remaining amount of developer.

  In the powder supply mechanism of the present invention, an elevating member that moves up and down in response to the vertical movement of the powder surface is placed on the powder surface, and an opening of the powder supply port corresponding to the elevating movement of the elevating member. Since the area is controlled to increase / decrease with the control member, it is possible to keep the remaining amount of powder at a predetermined amount easily and at low cost without arranging a sensor for detecting the remaining amount of powder in a container for storing powder. .

It is a schematic diagram for demonstrating the structure of the image forming apparatus which has a developing device provided with the powder supply mechanism by this invention. FIG. 2 is a schematic diagram showing one of the process units shown in FIG. 1 including the first embodiment of the toner supply mechanism of the developing device of the present invention when the toner remaining amount is low. FIG. 2B is a schematic diagram illustrating the first embodiment of FIG. 2A when the remaining amount of toner is large. 4A and 4B are schematic diagrams of a second embodiment showing a toner supply mechanism, in which FIG. 5A is a view when the remaining amount of toner is low, FIG. 5B is a view when the remaining amount of toner is medium, and FIG. It is a figure when there is much quantity. It is a perspective view which shows an example of the float member of FIG. FIG. 4B is a cross-sectional view of the float member of FIG. 4A. It is a perspective view which shows the other example of a float member. It is sectional drawing of the float member of FIG. 5A. 4A and 4B are schematic diagrams illustrating a toner supply mechanism according to a third embodiment, in which FIG. 5A is a view when the remaining amount of toner is low, FIG. 5B is a view when the remaining amount of toner is medium, and FIG. It is a figure when there is much quantity. FIGS. 9A and 9B are schematic diagrams illustrating a toner supply mechanism according to a fourth embodiment, in which FIG. 9A is a diagram when the remaining amount of toner is low, and FIG. FIG. 10 is a schematic diagram of a fifth embodiment illustrating a toner supply mechanism, and is a diagram before a powder supply device is attached to a powder consumption device. FIG. 10 is a schematic diagram illustrating a toner supply mechanism according to a fifth embodiment, in which a powder supply device is attached to a powder consumption device. FIG. 10 is a schematic diagram of a sixth embodiment illustrating a toner supply mechanism.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to embodiments shown in the drawings.

(Image forming device)
FIG. 1 is a sectional view schematically showing an image forming apparatus according to the present invention, and this image forming apparatus shows a color printer capable of forming images of a plurality of colors. Here, a tandem printer is exemplified as the “image forming apparatus”. However, the image forming apparatus is not limited to a printer, and includes a copying machine, a facsimile machine, a printing machine, and a complex machine in which these functions are combined.

  Referring to FIG. 1, a color printer 1 includes an image forming unit 3a in which a photosensitive member used as a latent image carrier and a device that performs a charging process, a developing process, and a cleaning process for the photoreceptor are collected for each color and stored in a process unit. 3b, 3c, 3d.

  The color printer 1 described in the present embodiment includes each image forming unit along an extending direction of an intermediate transfer belt 5 as an intermediate transfer member used for sequentially transferring images of different colors formed for each image forming unit. A tandem method in which the units 3a, 3b, 3c, 3d are arranged in parallel is used.

  The color printer 1 includes a housing main body 1A that can store the image forming unit 7, and the image forming unit 7 is disposed at substantially the center in the height direction of the housing main body 1A. An optical scanning device 9 is disposed above the image forming unit 7, and a waste toner container 10 and a sheet-like recording medium such as recording paper (hereinafter referred to as recording paper) are stacked below the image forming unit 7. A paper feed unit 11 equipped with a paper feed cassette that can be loaded is disposed.

(Imaging department)
The image forming units 3a, 3b, 3c, 3d used in the image forming unit 7 will be described below with reference to FIG. 2A schematically showing one image forming unit 3a. The other image forming units 3b, 3c, and 3d have the same configuration.

  In FIG. 2A, the image forming unit 3a is in contact with the photosensitive drum 13 disposed around the drum-shaped photosensitive member (hereinafter referred to as a photosensitive drum) 13 corresponding to a rotatable image carrier. A charging roller 15, a developing roller 17a corresponding to a developer carrying member that performs visible image processing of the electrostatic latent image formed on the photosensitive drum 13, and a supply roller 17b that supplies toner to the developing roller 17a. The developing unit 17 includes a process unit 21a in which a cleaning device 19 including a blade 19a that contacts the photosensitive drum 13 to scrape residual toner and a transport screw 19b for the collected toner is collectively stored.

  In the process unit 21a, the photosensitive drum 13 initialized and charged uniformly at a high potential by the charging roller 15 in the dark is supplied with the laser beams L1 to L4 from the optical scanning device 9 (in FIG. Are selectively exposed and scanned based on the image data, and an electrostatic latent image is formed which is composed of the low potential portion where the potential is attenuated by this exposure and the high potential portion by the initialization. The developing device 17 forms (develops) a toner image by transferring the toner to the low potential portion (or high potential portion) of the electrostatic latent image on the surface of the photosensitive drum 13 and processing the visible image. The developed toner image is transferred to the intermediate transfer belt 5 between the photosensitive drum 13 and the transfer roller 14.

  The process unit 21a has a configuration in which the developing device 17 can be built in the housing, and the toner image is moved along the circumferential direction by rotating the photosensitive drum 13 in the clockwise direction and conveyed toward the primary transfer position. It is supposed to be.

(Primary transfer)
As shown in FIG. 1, the latent image formation and toner image formation are performed by sequentially setting the timing in each of the process units 21a, 21b, 21c, and 21d. In order from the right of 21b, 21c, 21d, for example, images of different colors such as black, cyan, magenta, yellow, etc., are shown in the middle in which the upper stretched surface facing the process units 21a-21d in FIG. A primary image is sequentially transferred from the image carrier onto the transfer belt 5 to carry a full-color superimposed image.

(Secondary transfer)
The image transferred to the intermediate transfer belt 5 is collectively transferred onto the recording paper conveyed from the paper supply unit 11. That is, as shown in FIG. 1, the recording paper fed out from the paper feed cassette 11 a equipped in the paper feed unit 11 via the feed roller 23 is separated by the friction pad 25 in the middle of the recording paper, and then is secondary. When the transfer roller 27 is conveyed toward the secondary transfer position 29 where the transfer roller 27 is disposed, batch transfer is performed at that position. The batch-transferred recording paper is fixed by a fixing device 31 including a fixing roller 31 a and a heating roller 31 b, and then discharged to a paper discharge table 35 through a paper discharge roller 33. After the transfer, the intermediate transfer belt 5 passes through each image forming section, and then the residual toner is removed by a cleaning device to prepare for the next image transfer.

(Details of developing device)
Hereinafter, with reference to FIG. 2A and FIG. 2B, details of the developing device to which the powder supply mechanism according to the first embodiment of the present invention is applied will be described.
Here, the “developing device” is an example of a powder consuming device, and the “toner replenishing device” that supplies toner to the developing device is an example of a powder replenishing device.

(First embodiment)
The developing device 17 in FIG. 2A has a developing roller 17 in a developing housing 17c having a developing tank (powder container) that can store toner (dry one-component toner) as a powder used as a developer in a predetermined amount. The developing means composed of 17a or the like is assembled. A toner replenishing device 37 is detachably mounted on an upper portion of the developing housing 17c of the developing device 17, so that the whole of the developing device 17 and the toner replenishing device 37 can be handled as one unit (developing unit). Yes.

  The toner container 37a of the toner replenishing device 37 has a supply port 37f formed at the center of the bottom surface, and this supply port 37f is a supply port 17f formed at the center of the ceiling surface of the developing housing 17c when the toner replenishing device 37 is installed. , The vertical powder supply port 38 extending from the toner container 37a to the developing housing 17c is formed.

  A float member 41 is placed in a free state on the powder surface of the residual toner T1 in the developing housing 17c. The float member 41 includes a horizontal plate-like base portion 41a as a lifting member whose lower surface is in contact with the powder surface of the residual toner T1, and a rod portion 41b as a control member protruding upward from the center of the upper surface of the base portion 41a. Have The rod portion 41b has a cylindrical shape with its tip pointed in an upward conical shape. When the tip portion of the rod portion 41b is inserted into the powder supply port 38 as shown in FIG. 2B, the opening of the powder supply port 38 is opened. The area is reduced and the inflow amount of the replenishment toner T2 is limited. The size of the base portion 41a is slightly smaller than the internal dimension of the housing 17c, and the replenishment toner T2 supplied from the powder supply port 38 between the peripheral edge of the base portion 41a and the inner surface of the housing 17c. However, a gap that can flow smoothly from top to bottom is secured.

  The float member 41 is integrally formed with a relatively light material such as foamed resin, including the base portion 41a and the rod portion 41b, or integrally formed after the base portion 41a and the rod portion 41b are separately formed with a light material. Turn into. The specific gravity of the material used for the float member 41 is preferably smaller than the specific gravity of the residual toner T1. Thereby, the float member 41 can be stably floated on the powder surface of the residual toner T1. As will be described later, since the tip of the rod portion 41b is inserted into the powder supply port 38, it is desirable to use a material having a certain degree of strength and wear resistance for at least the tip of the rod portion 41b.

  A stopper 42 for restricting the lower limit position of the float member 41 is formed on the inner surface of the housing 17 c in the developing device 17. When the float member 41 descends due to a decrease in the residual toner T1, the lower surface peripheral portion of the base portion 41a of the float member 41 abuts against the stopper 42, so that the float member 41 stops descending.

  Since the float member 41 is configured to be lightweight as described above, the float member 41 is kept floating on the powder surface of the residual toner T1, and moves up and down following the vertical movement of the powder surface. When the residual toner T1 is relatively small and the powder surface is relatively low as shown in FIG. 2A, the float supply member 38 is at a low position and the powder supply port 38 is fully open. The replenishment toner T <b> 2 flows into the developing device 17 from the powder supply port 38. As the replenishing toner T2 flows in, the powder surface of the residual toner T1 gradually rises and at the same time the float member 41 also rises. As a result, the tip of the rod member 41b of the float member 41 is inserted into the powder supply port 38 as shown in FIG. 2B, and the opening area of the powder supply port 38 is reduced. As a result, the amount of the replenishment toner T2 flowing from the powder supply port 38 decreases, and when the opening area of the powder supply port 38 finally approaches almost zero, the replenishment toner T2 stops flowing completely.

  When the residual toner T1 is reduced by the operation of the developing device 17 and the powder surface is lowered as shown in FIG. 2A, the float member 41 is also lowered at the same time, the powder supply port 38 is fully opened again, and the replenishment toner T2 flows in. Begin to. As described above, the float member 41 moves up and down so as to follow the vertical movement of the powder surface of the residual toner T1, and at the same time increases or decreases the opening area of the powder supply port 38 at the tip of the rod portion 41b. Can be automatically held at a certain level.

  When the toner consumption amount of the developing device 17 rapidly increases, even if the powder supply port 38 is fully open, the inflow amount of the replenishment toner T2 is not in time, and the float member 41 is further lowered from the position of FIG. 2A. In this case, since the base portion 41a of the float member 41 abuts against the stopper 42 and prevents further lowering, the float member 41 is prevented from interfering with the rotary stirring member 39 and other driving components.

  A rotary stirring member 39 is disposed below the float member 41 as will be described later. The rotary stirring member 39 is for preventing packing of the residual toner T1, and the powder surface fluctuates due to the stirring action, and at the same time, the float member 41 swings. Even if the replenishment toner T2 temporarily accumulates on the float member 41 by this swinging action, it is immediately removed to the surroundings. Accordingly, the float member 41 is prevented from being buried in the replenishment toner T2 flowing from the powder supply port 38.

  Inside the developing housing 17c, a developing roller 17a as a developer carrying member is rotatably provided as in the conventional case, and the developing roller 17a rotates in the direction of the arrow (counterclockwise in FIG. 2A) during image formation. It is supposed to be. The developing roller 17a has a metal core, and the outer periphery is made of conductive rubber (for example, conductive urethane rubber or silicone rubber can be used) whose volume resistance is adjusted to about 10E5 to 10E7Ω. .

  A supply roller 17b as a toner supply member is rotatably contacted with the developing roller 17a. The contact nip between the developing roller 17a and the supply roller 17b is usually set to about 1 to 3 mm. The supply roller 17b is configured to efficiently transport the residual toner T1 in the developing housing 17c to the surface layer of the developing roller 17a by rotating in the counter direction indicated by an arrow (clockwise in FIG. 2A) with respect to the developing roller 17a. ing. As a general configuration of the supply roller 17b, a sponge roller or the like in which foamed polyurethane made semiconductive by mixing carbon on the outer periphery of a metal core is attached.

  On the peripheral surface of the developing roller 17a, a developing blade 17d is disposed on the downstream side of the contact nip with the supply roller 17b. The residual toner T1 conveyed from the supply roller 17b onto the surface of the developing roller 17a is regulated to a predetermined amount by controlling the layer thickness by the developing blade 17d. Further, at the same time as the toner layer thickness is controlled, the toner is frictionally charged between the developing blade 17d and the developing roller 17a.

  A rotating stirring member 39 is disposed in the developing housing 17c in the vicinity of the contact nip between the developing roller 17a and the supply roller 17b. The rotating agitating member 39 rotates in the direction of the arrow to prevent the residual toner T1 from being packed, and the toner powder pressure concentrates on the supply roller 17b and reduces the load on the supply roller 17b. Yes.

(Second Embodiment)
Next, 2nd Embodiment of this invention is described based on FIGS. 3-4B. This 2nd Embodiment changes the shape of the rod part 41b of the float member 41 from the thing of 1st Embodiment, and makes the rod part 41b whole conical shape. Accordingly, the cross-sectional area of the rod portion 41b is maximum at the base end portion, and the cross-sectional area gradually decreases toward the tip end portion, and becomes the minimum cross-sectional area at the forefront. When the rod member 41b has such a conical shape, as shown in steps in FIGS. 3A to 3C, when the float member 41 is in a low position as shown in FIG. As the opening area of the powder supply port 38 increases and the amount of powder inflow increases and the float member 41 rises as shown in FIG. 3B or 3C, the opening area of the powder supply port 38 decreases. As a result, the amount of powder inflow is reduced. As described above, by changing the opening area of the powder supply port 38 in accordance with the height of the float member 41, the amount of the replenishing toner T2 can be finely controlled to keep the amount of the residual toner T1 at an appropriate amount. it can.

  The float member 41 needs to always float on the powder surface of the residual toner T1 in order to automatically maintain the amount of the residual toner T1 at a certain level. Therefore, in the second embodiment, as shown in FIGS. 4A and 4B, the float member 41 has a hollow structure and is made lightweight by using a foamed resin. That is, the upper half of the base portion 41a of the float member 41 is integrally formed in a rectangular plate shape by PS (polystyrene) or ABS resin R1 generally used as a resin component, and has a hollow portion 41c at the center portion thereof. The conical rod portion 41b is integrally formed. The lower half of the base portion 41a is made of a rectangular plate-shaped foamed resin R2, and this foamed resin plate is bonded and integrated with the resin plate with an adhesive so as to obtain the necessary buoyancy as the float member 41.

  When the residual toner T1 is a dry one-component toner, the bulk density is, for example, about 0.36 g / cc. Therefore, in order to float the float member 41 on the powder surface of the residual toner T1 having such a bulk density, the float toner 41 is floated. The specific gravity of the member 41 needs to be at least less than 0.36. The density of the PS or ABS resin is about 1.0 to 1.1 g / cc, but when the float member 41 is formed only with these resins, the apparent volume (bulk volume) of the float member 41 is theoretically increased. On the other hand, at least two-thirds or more must be a hollow region.

  However, it is practical to use a foamed resin such as urethane foam in combination with PS, ABS resin, or the like because a float shape that hollows out more than two-thirds of the apparent volume is practically difficult to realize. Therefore, as described above, most of the base portion 41a of the float member 41 is formed of the foamed resin R2, and the rod portion 41b of the float member 41 and the upper half of the base portion 41a include the hollow portion 41c made of PS or ABS resin R1. Thus, the float member 41 having a specific gravity smaller than that of the dry one-component toner is realized.

  In order to obtain sufficient buoyancy, the base portion 41a of the float member 41 needs to expand its vertical and horizontal dimensions to the limit of the internal dimensions in the developing housing 17c. T2 is easily deposited on the base portion 41a. Therefore, in order to make it difficult for the replenishing toner T2 to accumulate on the base portion 41a, a plurality of through holes 41d may be provided in the base portion 41a of the float member 41 as shown in FIG. 5A. As a result, the replenishment toner T2 that has fallen onto the base portion 41a smoothly exits below the float member 41 through the through-hole 41d, thereby preventing the base portion 41a from being buried in the replenishment toner T2. Further, in order to facilitate passage of the replenishment toner T2 and to stabilize the floating of the base portion 41a, as shown in the cross-sectional view of FIG. 5B, the cross-sectional shape of the lattice rib 41e between the through holes 41d of the base portion 41a is The cross-sectional shape may be a substantially triangular shape or an isosceles triangular shape having an acute angle top and a flat bottom. As a result, the replenishment toner T2 is less likely to be deposited on the base portion 41a, and a large contact area of the base portion 41a with the powder surface of the residual toner T1 can be secured, so that the float member 41 is placed on the powder surface. Can make it easier to float.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. In this third embodiment, there are three rod portions 41b of the float member 41, the height of each rod portion 41b is made different, and the powder supply ports are made three so that these rod portions 41b can enter respectively. Is. As the replenishing toner T2 is supplied and the float member 41 is raised, first, the highest first rod portion 41b1 enters the first powder supply port 38a as shown in FIG. (B) As shown in FIG. 6C, the second rod portion 41b2 and the third rod portion 41b3 enter the second and third powder supply ports 38a and 38c. The rod portions 41b1 to 41b3 may have different tip shapes as well as heights, and the powder supply ports 38a to 38c may have different sizes. Further, the number of the rod portions 41b and the powder supply ports 38 may be two or four or more as necessary. As described above, as the float member 41 moves up, the height of the float member 41, that is, the powder surface is obtained by making the plurality of rod portions 41b1 to 41b3 sequentially enter the plurality of powder supply ports 38a to 38c. The inflow amount of the replenishment toner T2 can be set more finely according to the height of the toner.

(Fourth embodiment)
Next, 4th Embodiment of this invention is described based on FIG. 7 (A) (B). In this fourth embodiment, a lid member 41f formed in a disc shape with an elastic material such as rubber is fixed horizontally at the tip of the rod portion 41b of the float member 41, and powder is supplied by the lid member 41f. The mouth 38 is opened and closed. The rod portion 41b itself may be sufficiently thinner than the powder supply port 38 and may have the same diameter from the root to the tip. In the fourth embodiment, since the lid member 41f can be elastically deformed, the lid member 41f has a magnitude relationship between the upward pushing force from the powder surface of the residual toner T1 and the downward pressure of the replenishment toner T2. It deforms with good responsiveness, and the function of quickly adjusting the inflow amount of the replenishing toner T2 from the powder supply port 38 is obtained.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described with reference to FIGS. 8A and 8B. In the fifth embodiment, a rod portion 45 as a control member for controlling the opening area of the powder supply port 38 is disposed on the side of a toner replenishing device 37 as a powder replenishing device to cope with the vertical movement of the powder surface. Then, a base portion 46 as a lifting member that moves up and down is arranged on the developing device 17 side as a powder consumption device. Before the toner replenishing device 37 is attached to the developing device 17, the rod portion 45 and the base portion 46 are independent of each other. However, the toner replenishing device 37 is lowered in the direction of the arrow in FIG. 17, the convex portion 46 a of the base portion 46 is fitted and connected to the lower end concave portion 45 a of the rod portion 45 so as to function as an integral float member.

  The rod portion 45 has an upper end portion that is a dish-shaped portion 45b having a diameter larger than that of the supply port 37f, and a lower portion that is a fitting portion 45c that can be fitted to the supply port 37f, and the dish-shaped portion 45b and the fitting portion. 45c constitutes a lid member that closes the supply port 37f. Further, a lower side of the fitting portion 45c is a leg portion 45d that protrudes outward from the toner container 37a by a predetermined length. Note that the leg portion 45d is formed in a tapered shape whose lower end is enlarged to the same extent as the size of the supply port 37f.

  In the state of the toner replenishing device 37 alone, the rod portion 45 has a dish-like portion 45b and a fitting portion 45c, and thus functions as a lid member that closes the supply port 37f (powder supply port 38) of the toner container 37a. It is possible to serve as well. In this case, a protective cylinder 47 longer than the leg portion 45d is attached so as to cover the leg portion 45d protruding outside the supply port 37f so that the rod portion 45 is not accidentally pushed into the toner container 37a. It is preferable to cover the seal 48 from above. This eliminates the concern that the replenishment toner T2 in the toner container 37a leaks to the outside. The protective cylinder 47 and the seal 48 are removed before the toner replenishing device 37 is attached to the developing device 17.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described with reference to FIG. In the sixth embodiment, a float member 52 as an elevating member that moves up and down in response to the vertical movement of the powder surface, and a rod portion 51 as a control member that controls increase / decrease in the opening area of the powder supply port 38, It is composed separately. That is, a horizontal plate-like lever 50 that can swing in the vertical direction about a fulcrum pin 49 fixed to the inner surface of the developing housing 17c is provided, and can enter the powder supply port 38 on the upper surface on the tip side of the lever 50. The rod portion 51 is fixed vertically, and a plate-like float member 52 is attached to the lower surface of the lever 50 opposite to the rod portion 51 via a slide mechanism including a long hole 50a and a pin 52a. The long hole 50a is formed to extend in the shape of a plane in the longitudinal direction and the width direction of the lever 50, and the pin 52a is inserted in the width direction of the long hole 50a (direction perpendicular to the paper surface of FIG. 9). The central portion in the width direction of the pin 52a is connected to the upper portion of the support 52b extending to the long hole 50a through the notch hole on the lower surface of the lever 50, and the lower portion of the support 52b is fixed to the upper surface of the float member 52. The float member 52 is made of a light material like the base portion 41a, and has a hollow structure as required, so that the float member 52 moves up and down in accordance with the vertical movement of the powder surface.

  In the sixth embodiment, when the powder surface of the residual toner T1 in the developing housing 17c rises due to the inflow of the replenishing toner T2 from the powder supply port 38, the float member 52 rises correspondingly. When the float member 52 rises, the lever 50 rotates upward about the fulcrum pin 49, and the rod portion 51 enters the powder supply port 38. As a result, the supply amount of the replenishing toner T2 is reduced, and the height of the powder surface of the residual toner T1 is automatically maintained at a constant level. In place of the stopper 42 shown in FIGS. 2A and 2B, an appropriate stopper for restricting the lowering limit of the lever 50 may be disposed in the vicinity of the fulcrum pin.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the one-component developing device in the tandem type electrophotographic apparatus, but can also be applied to a developing machine of a monochrome machine and a four-cycle type electrophotographic apparatus. is there. In addition, the present invention is not only applied to the developer supply mechanism, but can be generally applied to a powder supply mechanism for a container for storing a predetermined amount of powder. For example, it is recovered without being transferred to a transfer body in a transfer process. The present invention can also be applied to a waste developer and waste toner supply mechanism for a waste toner collection container for storing the waste developer and waste toner.

17 Developing device 17c Developing housing 21a-21d Process unit 37 Toner replenishing device 38 Powder supply port 41 Float member 41a Base part (elevating member)
41b Rod part (control member)
41c Hollow part 41d Through-hole

JP-A-4-323680 JP 2007-293128 A

Claims (12)

A container for containing powder;
A powder supply port disposed at the top of the container;
An elevating member placed on the powder surface in the container and moving up and down in response to the vertical movement of the powder surface accompanying the increase or decrease of the powder in the container;
A control member for increasing / decreasing the opening area of the powder supply port in response to the lifting / lowering movement of the lifting member;
With
The elevating member is composed of a base portion placed on the powder surface, the control member is composed of a rod portion capable of entering the powder supply port, and the rod portion is integrated with the base portion. Body supply mechanism. The powder according to claim 1 , wherein the container constitutes a part of a powder consuming apparatus, and the powder supply port constitutes a part of a powder replenishing apparatus detachably attached to the container of the powder consuming apparatus. Supply mechanism. When the powder supply port is disposed downward and the base portion is raised, the rod portion enters the powder supply port to reduce the amount of powder supply, and when the base portion is lowered, the rod portion is the powder. The powder supply mechanism according to claim 1 or 2 , wherein the powder supply amount increases by exiting from the body supply port. The powder supply mechanism according to claim 3 , wherein a tip portion of the rod portion that can enter the powder supply port is gradually narrowed from the base portion side toward the tip side. The powder supply mechanism according to any one of claims 1 to 4 , wherein a plurality of the powder supply port and the rod portion are provided. The powder supply mechanism according to claim 5 , wherein the plurality of rod portions have different heights. The powder supply mechanism according to any one of claims 1 to 6 , wherein at least a part of the base portion is made of a foamed resin. The powder according to claim 2 , wherein the base portion and the rod portion are separable, the base portion is disposed on a container side of the powder consumption device, and the rod portion is disposed on the powder supply device side. Body supply mechanism. When the powder replenishing device is attached to the powder consumable device, a rod portion on the powder replenishing device side is connected to a base portion on the powder consumable device side by an uneven fitting structure. Item 9. The powder supply mechanism according to Item 8 . A developing device comprising the powder supply mechanism according to any one of claims 1 to 9 for supplying a developer. A process unit comprising the powder supply mechanism according to any one of claims 1 to 9 for supplying a developer. An image forming apparatus comprising the powder supply mechanism according to claim 2 for supplying a developer, wherein the powder is a developer, the powder consuming device is a developing device, and the powder replenishing device is a developer replenishing device. .

Images