JPH06161242A - Developing device - Google Patents

Abstract

(57) [Summary] [Purpose] To accurately detect the amount of toner remaining in the developer container. [Structure] AC power source 33, DC power source 3 on developing sleeve 23
Connect 5. A condenser is formed by the developing sleeve 23 and the stirring member 29 facing the developing sleeve 23, and the electrostatic capacity of the condenser is detected by the remaining amount detecting means 30. The stirring member 29 has a spiral portion 29b and rotates to well stir the toner along the rotation shaft 29a. Further, the spiral portion 29b is
A fixed number (three positions in FIG. 3) of the closest parts 29c closest to the developing sleeve 23 are provided regardless of rotation.
This is because even if the spiral portion 29b rotates, the developing sleeve 23
Shows that the posture of the spiral portion 29b with respect to
As a result, the change in the electrostatic capacity and the change in the remaining amount of toner correspond accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device suitable for being mounted on an image forming apparatus such as an electrophotographic copying machine, an electrostatic recording device, a laser beam printer, and the like, and more particularly to a developing device housed in a developing container. The present invention relates to a developing device provided with a remaining amount detecting means for detecting the remaining amount of an agent.

[0002]

[Prior art]

<Prior Art 1> FIG. 10 schematically shows a conventional developing device mounted on an image forming apparatus such as an electrophotographic copying apparatus, an electrostatic recording apparatus, and a laser beam printer.

The developing device 21 is arranged around a photosensitive drum (image carrier) 19 on the surface of which an electrostatic latent image is formed by an unillustrated charging device, exposing means, and the like. The photosensitive drum 19 is provided on the substantially opposite side to the photosensitive drum 19.
A cleaning device 22 for removing and collecting the toner (developer) remaining on the top is provided.

The developing device 21 includes a developing sleeve (developer carrying member) 23 that carries and conveys toner, a blade 26 having magnetism, a developing container 25 that stores toner, a stirring member 27 that stirs the toner, and the remaining amount of the toner. An antenna 24 for detecting The stirring member 27 rotates in the direction of the arrow, destroys the toner in the developing container 25, and moves it toward the developing sleeve 23.

In the developing device 21 as described above, the remaining amount of toner in the developing container 25 is detected by the antenna 24 in consideration of the downsizing of the entire device, the running cost for forming the cartridge, and the like. However, this is
The principle is as follows.

That is, for example, in the developing device 21, the electrostatic capacity between the developing sleeve 23 and the antenna 24, which changes depending on the amount of toner in the developing container 25, is shown in FIG.
The detection is performed by the equivalent circuit as shown in. Here, in the drawing, 33 is an AC power supply for applying a developing bias, and 35 is
Is the same DC power source, C is a capacitor composed of the antenna 24 and the developing sleeve 23, C ₂₃ is the developing sleeve 23 as an electrode, and C ₂₄ is the antenna 24 as an electrode. The AC power supply 33 is 1800 Hz, 160
Generates a 0 V _PP square wave. In this circuit, the capacitance of the capacitor C, the electrode C _23, C ₂₄ to change the amount of toner between the developing sleeve 23 and the antenna 24
It changes with the permittivity in between. As a result, the magnitude of the differential waveform of the AC component of the developing bias, which appears at both ends of the load resistor 31 of the remaining amount detecting means 30, changes, and the monitor 32 measures this signal to measure the amount of toner in the developing container 25. Can be detected. <Prior Art 2> Conventionally, as shown in FIG. 38, a developing device such as an LBP or a copying machine has been used.

In the figure, reference numeral 25 is a developing container for storing a developer (toner), and a developing sleeve 23 for carrying and carrying toner is provided in the lower opening 25b of the developing container 23.
9 are arranged close to each other at a predetermined distance. Further, a developing blade 26 is provided which is in contact with the developing sleeve 23 and forms a layer of toner in a predetermined thickness. Further, a stirring member (toner stirring mechanism) for stirring the toner inside the developing container 25 and sending it to the developing sleeve 23.
27a is provided.

When the amount of toner in the developing container 25 becomes low, a toner remaining amount detecting device (remaining amount) is provided to warn that the toner needs to be replenished or the developing container 25 needs to be replaced. Detection means). As the remaining toner amount detecting device, an antenna system for detecting the electrostatic capacity of the toner existing between the developing sleeve 23 and the antenna 24 arranged at a predetermined position, or a pressure of the toner by using a piezo element is detected. The piezo method is used. In FIG. 38, 18 is a cartridge container, 20 is a corona discharger, and 22 is a cleaning device.

[0009]

[Problems to be Solved by the Invention]

<Problem of the First Invention> However, according to the conventional technique 1, as shown in FIG. 10, since the antenna 24 is fixed in the vicinity of the developing sleeve 23, the antenna 24 has a toner in the vicinity of the developing sleeve 23. And the unevenness of density occurs due to defective toner circulation in the longitudinal direction of the developing sleeve 23. In order to prevent this, FIG.
As shown in FIG. 3, instead of the antenna 24, a crank-shaped stirring member 29 is installed near the developing sleeve 23 also as an antenna, and this is rotated to stir the toner. However, the stirring member 29 close to the developing sleeve 23
Since the capacitance of the capacitor C composed of the developing sleeve 23 and the developing sleeve 23 varies with the stirring cycle T of the stirring member 29,
The remaining toner amount cannot be detected accurately. That is, as shown in FIG. 11, the electrostatic capacity of the capacitor C composed of the developing sleeve 23 and the stirring member 29 is used for detecting the remaining toner amount, but the stirring member 29 shown in FIGS. 12 and 13 is used.
Is formed in a crank shape, and when it rotates, the central portion thereof moves away from the developing sleeve 23 or approaches the developing sleeve 23. As shown in FIG. Changes. As a result,
In FIG. 11, the voltage appearing across the load resistor 31 also changes periodically, causing a problem that the remaining toner amount cannot be accurately detected.

Therefore, the first aspect of the present invention is the remaining amount detecting means 30.
Provided is a developing device capable of accurately detecting the remaining amount of toner by preventing the posture of the stirring member with respect to the developer carrying member from changing even when the stirring member that functions as a part of the developing device rotates. That is the purpose. <Problem of the Second Invention> Further, according to the conventional technique 1, the antenna 24 is fixed in the vicinity of the developing sleeve 23 in parallel therewith, and the remaining amount detecting means (30) includes the developing sleeve 23 and the antenna. The remaining amount of toner is detected by detecting the electrostatic capacitance between the sensor and 24. For this reason,
Although the toner in the vicinity of the developing sleeve 23 is uniformly reduced in the longitudinal direction of the developing sleeve 23 and an unnecessary space is not formed between the developing sleeve 23 and the antenna 24, the remaining toner amount can be accurately detected. If this condition is not met, the remaining amount detecting means may not be able to detect toner accurately.

However, even if the image forming apparatus has a maximum sheet-passing width (maximum left-right width) of B4 size, for example, B5
Some users print only size paper. In the image forming apparatus of this user, in the longitudinal direction near the developing sleeve 23, the toner in the portion corresponding to the B5 size width decreases, but the toner in the portion corresponding to the sizes other than B5 remains, and the developing sleeve 23. And antenna 2
The electrostatic capacity between No. 4 and No. 4 was not sufficiently reduced by the remaining toner, and the toner was exhausted in the portion of the width of B5 size, and the image white spots sometimes occurred.

In the image forming apparatus in which B4 or A3 has the maximum sheet passing width as described above, when small size paper such as B5 or A4 is continuously printed, the remaining amount detection for detecting the remaining amount of toner in the developing container 25 is detected. In the means 30, image white spots may occur before the warning light is turned on. Therefore, generally, a screw type stirring member is added so that the toner is always supplied to the small size paper passing portion. There is. Therefore, the developing device is large-scaled.

In view of the above, the second aspect of the present invention includes a telescopic electrode, a movable electrode, and a divided electrode that change in accordance with the lateral width (sheet passing width) of the transfer material, thereby providing a simple warning lamp configuration. An object of the present invention is to provide a developing device that prevents occurrence of white spots in an image before lighting. <Problem of the Third Invention> Further, according to Conventional Technique 2,
The remaining amount detection accuracy varies depending on the accuracy of arranging the toner remaining amount detecting elements such as the antenna 24 and the piezo element, the remaining amount of toner in the developing container 25, and the like. Alternatively, there is a problem that the cost becomes high.

Therefore, according to the third aspect of the present invention, by disposing the conductive member and the electrodes sandwiching the front and back of the conductive member on the inclined surface of the developing container, the remaining amount of the toner in the developing container can be accurately measured with a simple structure. It is an object of the present invention to provide a developing device which is adapted to detect.

[0015]

The present invention (first to third inventions) has been made in view of the above circumstances, and has the following configurations, respectively. <Means of the First Invention> A first invention is a developing container containing a developer, and a developing container rotatably disposed in a lower opening of the developing container and supplying the developer to an image carrier. An agent carrier, a rotatable stirring means for moving the developer in the developing container toward the developer carrier, and a remaining amount detecting means for detecting the remaining amount of the developer in the developing container. In the developing device, the agitating means surrounds the rotary shaft parallel to the developer carrying member and the circumference of the rotary shaft in a spiral shape, and the agitating device is provided with respect to the developer carrying member regardless of the rotation of the agitating device. And a spiral part having a certain number of closest parts, wherein the remaining amount detecting means detects the electrostatic capacitance between the closest part of the stirring means and the developer carrying member. . <Means of Second Invention> Further, a second invention is to provide a developing container accommodating a developing agent, a developing container rotatably disposed at a lower opening of the developing container and supplying the developing agent to an image carrier. In a developing device having a developer carrying member for detecting the remaining amount of the developer in the developing container, the remaining amount detecting unit faces the developer carrying member and forms an image. An expansion / contraction electrode that is expandable / contractible in the left / right width direction of the target transfer material, and an interlocking mechanism that expands / contracts the expansion / contraction electrode corresponding to the left / right width of the transfer material, and the expansion / contraction electrode and the developer after expansion / contraction. It is characterized in that the capacitance between the carrier and the carrier is detected.

Further, a developing container accommodating the developing agent, a developing agent carrier rotatably disposed at the lower opening of the developing container and supplying the developing agent to the image carrier, and the inside of the developing container. In a developing device having a remaining amount detecting means for detecting the remaining amount of the developer, the remaining amount detecting means includes a plurality of moving electrodes arranged so as to be able to come into contact with and separate from the developer carrier, A moving mechanism for moving the moving electrode at a position corresponding to the left-right width of the transfer material to be image-formed to the developer carrier, and the moving electrode approaching the developer carrier and the image carrier. It is characterized in that the capacitance between them is detected.

Further, a developing container for accommodating the developing agent, a developing agent carrier rotatably disposed at the lower opening of the developing container and supplying the developing agent to the image carrier, and the inside of the developing container. In the developing device having a remaining amount detecting unit for detecting the remaining amount of the developer, the remaining amount detecting unit divides the divided electrode corresponding to the left and right width of the transfer material and the left and right width of the transfer material. An interlocking mechanism for activating the divided electrodes in corresponding portions is provided, and the electrostatic capacitance between the divided electrodes corresponding to the left and right width of the transfer material and the image carrier is detected. <Means of Third Invention> Furthermore, a third invention is a developing container having an inclined surface at the bottom which descends toward a lower opening,
In a developing device including a developer carrier disposed in the opening, a remaining amount detecting unit including a sheet-shaped conductive member and electrodes sandwiching the front and back of the conductive member is arranged on the inclined surface. It is characterized by being installed.

In this case, the remaining amount detecting means may be arranged so as to be able to come into contact with and separate from the developer carrying member.

[0019]

[Action]

<Operation of First Invention> Based on the above configuration, according to the first invention, the attitude of the stirring member with respect to the developer carrying member can be kept constant regardless of the rotation of the stirring member.
When the remaining amount of the developer is constant, the electrostatic capacity between the developer carrier and the stirring member can always be kept constant. Therefore, by detecting this electrostatic capacitance, it is possible to accurately grasp the amount of the developer remaining in the developing container. <Operation of Second Invention> Further, according to the second invention, the lengths of the expandable electrodes, the movable electrodes, and the divided electrodes can be appropriately set according to the lateral width of the transfer material. The remaining amount of the developer can be accurately detected according to the left and right width of the transfer material used for. <Operation of Third Aspect of Invention> Further, according to the third aspect of the invention, since the remaining amount detecting means is composed of the sheet-like conductive member and the electrode value for sandwiching the sheet-like conductive member from the front and back, the surface of the remaining amount detecting means It is possible to accurately detect the amount of toner that is in the state of.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. <Embodiment 1 of the First Invention> FIG. 1 is a schematic sectional view of a copying machine 1 as an image forming apparatus equipped with a developing device according to the present invention.

This copying machine 1 is constructed by mounting a process cartridge 3 in a main body 2, and above the process cartridge 3 in the main body 2, a short focus optical element array 5 and an original plate illumination lamp which constitute an optical system. 6, a paper feed cassette 7, a paper feed roller 9, a guide member 10, a transfer corona discharger 11, a conveyance path 12, a fixing device 13, and a discharge roller 15 are sequentially arranged below from the right side of FIG. Has been done. Further, a paper discharge tray 16 is provided outside the main body 2, and a document table 17 is provided on the upper surface.

The process cartridge 3 includes a photosensitive drum 19 as an image bearing member which is rotationally driven in the direction of the arrow, a corona discharger 20 arranged around the photosensitive drum 19,
The developing device 21 and the cleaning device 22 according to the present invention are integrally incorporated to form a unit.

Next, the operation of the entire copying machine 1 will be briefly described.

The surface of the photosensitive drum 19 has a corona discharger 2
0 is uniformly charged, and then the original image on the original table 17 illuminated by the original table illumination lamp 6 is illuminated through the short-focus optical element array 5 to form an electrostatic latent image corresponding to the original image. It is formed. This electrostatic latent image is transferred to the developing device 2
Toner is attached by the first developing sleeve 23 and is visualized as a developed image (toner image).

On the other hand, the transfer material is taken out from the paper feeding cassette 7 by the paper feeding roller 9, and the transfer material is guided along the guide member 10 to the photosensitive drum 19 and the transfer corona discharger 1.
Transported between 1 and 1. Then, the toner image formed on the photosensitive drum 19 is transferred onto the transfer material by the transfer corona discharger 11. The transfer material that has received the transfer of the toner image is sent to the fixing device 13 via the transport path 12, and the toner image is heated and pressed there to be fixed. Then, the transfer material on which the toner image is fixed is discharged to the outside of the main body 2 by the discharge roller 15 and is stacked on the paper discharge tray 16.

Next, the developing device 21 will be described in detail with reference to the enlarged view of FIG. The developing device 21 includes a developing container 25 that stores toner (developer). Developer container 2
The whole 5 is formed in a box shape of a substantially rectangular parallelepiped, has a slope 25a that is gently inclined at the bottom, and the lower side of the slope 25a is in the left-right direction (direction perpendicular to the plane of FIG. 2). ) Has a long rectangular lower opening 25b. The lower opening 25b is almost entirely closed by a cylindrical developing sleeve 23 and a plate-shaped blade 26.

The developing sleeve 23 is rotatably supported by the left and right side plates (not shown) of the developing container 25 with its axis directed to the left and right, and faces the photosensitive drum 19 to rotate in the direction of arrow R1. Has become. Blade 26
Is formed in a rectangular shape that is long in the left-right direction, its upper end side is fixed to the front plate 25c of the developing container 25, and its lower end edge is opposed to the outer peripheral surface of the developing sleeve 23 via a minute gap G. ing. The minute gap G regulates the amount of toner applied to the developing sleeve 23 and carried and conveyed, and adjusts the amount of toner supplied from the developing device 21 to the photosensitive drum 19.

The toner carried and conveyed by the developing sleeve 23 is moved toward the developing sleeve 23 by the stirring members (stirring means) 27 and 29 arranged in the storage container 25. The stirring member 2 farther from the developing sleeve 23
7 is rotatably supported by the left and right side plates (not shown) of the developing container 25, and is rotationally driven in the direction of arrow R2 by a driving member (not shown). This stirring member 27
Is formed of, for example, a crank-shaped rod-shaped member, and in the case of a crank, rotates around a shaft portion 27a corresponding to a crankshaft, and a pin portion 27b also corresponding to a crankpin.
Rotates in the direction of arrow R2 to move the toner to the developing sleeve 23 side. The rotation radius of the stirring member 27 is set to be large so that the toner in the developing container 25 can be effectively moved to the developing sleeve 23 side.

On the other hand, the stirring member 29 on the side closer to the developing sleeve 23 also serves as a part of the remaining amount detecting means 30 for detecting the remaining amount of toner, in addition to the stirring action of the toner. As shown in FIG. 3, the stirring member 29 includes a rotating shaft 29a parallel to the developing sleeve 23 and a spiral portion 29b surrounding the rotating shaft 29a. In the stirring member 29, a rotation shaft 29a is rotatably supported by left and right side plates (not shown) of the developing container 25, whereby the spiral portion 29b rotates in the arrow R3 direction. FIG. 4 is a schematic view of the stirring member 29 and the developing sleeve 23 of FIG. 2 as viewed from the direction of arrow A. The spiral portion 29b has a certain number (three locations in the figure) of portions 29c that are closest to the outer peripheral surface of the developing sleeve 23 (hereinafter referred to as "closest portions") 29c. These closest parts 29c are spiral parts 29
Since it is on the position b, it reciprocates in the axial direction along the rotation axis 29a with the rotation of the spiral portion 29b, but its overall number does not change. In other words,
Since each part of the spiral part 29b is always equal in distance from the rotation axis 29a, the spiral part 29b is irrespective of its rotation,
The overall attitude with respect to the developing sleeve 23 is always the same. As shown in FIG. 3, the left and right ends of the spiral portion 29b respectively have linear connecting portions 29d that are perpendicular to the rotating shaft 29a, but these are configured to face the same direction. That is, the two connecting portions 2
9d is formed at the same position in the rotation direction around the rotation axis 29a, so that the start and end of the spiral portion 29b are located at the same position in the same rotation position. Two connecting parts 29
When the position of d in the rotation direction is different, the number of the closest portions 29c increases or decreases up to 1 depending on the rotation position of the spiral portion 29b, whereby the attitude of the spiral portion 29b with respect to the developing sleeve 23 is increased. It will change.
For example, when the spiral portion 29b is one and a half turns, the positions of the two connecting portions 29d are different by 180 degrees. In this case, the closest part 29c changes to one place or two places.

The toner in the developing container 25 is attached to the electrostatic latent image on the photosensitive drum 19 via the developing sleeve 23 as the image formation progresses, and the toner in the vicinity of the developing sleeve 23 is removed. It is consumed gradually. At this time, the toner in the developing container 25 cannot easily move toward the developing sleeve 23 only by its own weight. Therefore, by rotating the stirring member 27 in the arrow R2 direction and rotating the stirring member 29 in the arrow R3 direction,
The toner is broken and moved, and is effectively supplied to the surface of the developing sleeve 23 as indicated by an arrow B. At this time, the developing sleeve 2
The third-side stirring member 29 not only moves the toner toward the developing sleeve 23 by the rotation of the spiral portion 29b, but also moves along the rotating shaft 29a, that is, along the longitudinal direction of the developing sleeve 23. It is also possible to stir the toner in the vicinity of the outer peripheral surface of the developing sleeve 23 evenly, and to make the toner density of the final copy uneven, particularly the toner density in the left-right direction with respect to the moving direction of the transfer material as compared with the conventional case. It is also possible to effectively eliminate unevenness.

The stirring member 29 not only performs the stirring action as described above, but also acts as an antenna of the remaining amount detecting means 30 as shown in FIG. The remaining amount detecting means 30 is mainly composed of a load resistor 31 and a monitor 32, and detects the electrostatic capacitance between the stirring member 29 and the developing sleeve 23 to detect the stirring member 29 and the developing sleeve 23. The amount of toner in the developing container 25 is detected and the remaining amount of toner in the developing container 25 is estimated by this. This will be described with reference to FIGS. The developing sleeve 23 has
An AC power supply 33 and a DC power supply 35 are connected to each other, whereby a superimposed current of AC and DC flows in the developing sleeve 23. As shown in the equivalent circuit of FIG. 5, the developing sleeve 23 serves as one electrode C ₂₃ , and the agitating member 29 facing the developing sleeve 23 serves as the other electrode C ₂₉ to form the capacitor C. In this circuit, the capacitor C
The electrostatic capacitance of is changed according to the dielectric constant between the electrodes C ₂₃ and C _{29 which is} changed depending on the amount of toner between the developing sleeve 23 and the stirring member 29. As a result, the magnitude of the differential waveform of the AC component of the developing bias, which appears at both ends of the load resistor 31 of the remaining amount detecting means 30, changes, and this signal is measured by the monitor 32. The amount can be detected.

FIG. 6 shows a change in electrostatic capacitance between the stirring member 29 and the developing sleeve 23 when the stirring member 29 rotates in the stirring cycle T. From this figure, the capacitance is 10 pF when the amount of toner remaining in the developing container 25 is 200 g.
(Picofarad), 5pF when the remaining amount is 0g
And, in any case, it becomes constant. That is, the developing container 2
If the remaining amount of toner in 5 is constant, the electrostatic capacitance is constant regardless of the stirring cycle T of the stirring member 29.

FIG. 7 shows the relationship between the remaining amount of toner in the developing container 25 and the electrostatic capacity. From this figure, the electrostatic capacity is 10 pF when the toner remaining amount is 90 g or more, and 5 pF when the toner remaining amount is 20 g or less.
In the range of decreasing to, the capacitance decreases almost linearly. That is, within this range, the remaining toner amount and the electrostatic capacitance have a one-to-one correspondence, and the remaining toner amount is uniquely determined with respect to the electrostatic capacitance and vice versa. Will be done. In the present embodiment, it has been experimentally confirmed that white spots occur in an image of a final copy when the remaining amount of toner in the developing container 25 is 30 g or less. Therefore, in the present embodiment, when the detection level becomes 7 pF (remaining toner amount is approximately 40 g) in consideration of the margin with respect to the electrostatic capacitance of 6 pF at 30 g, a toner remaining amount warning lamp (not shown) is turned on. Set to do. Therefore, when the warning light is turned on, the remaining amount of toner in the developing container 25 is 40 g, and there is still room for 30 g where white spots occur. If toner is replenished at this point,
It is possible to prevent white spots from occurring.

By thus forming the stirring member 29 in the spiral shape as described above, it is possible to uniquely correspond the remaining toner amount and the electrostatic capacity near the detection level, and thus the developing container. It is now possible to accurately detect the remaining amount of toner within 25 and properly understand the toner supply timing. <Embodiment 2 of First Invention> Next, Embodiment 2 of the developing device according to the present invention is shown in FIG. In FIG. 8, the same members as those in FIG. 3 are designated by the same reference numerals, and the description thereof will be omitted.

The stirring member 36 of this embodiment is a rotary shaft 36a.
Two spiral parts 36b and 36b are arranged around the circumference of the. The two spiral portions 36b are twisted in the same direction by half a turn, and each start portion is connected to both ends of one connecting portion 36d and each end is connected to both ends of the other connecting portion 36d. Has been done. The two connecting portions 36d and 36d face the same direction as each other, and thus the two spiral portions 36b and 36b are arranged symmetrically with respect to the rotation axis 36a. Therefore, the spiral portions 36b, 36b always have the two closest portions 36c, 36c regardless of the rotation thereof, and the developing sleeve 23
The average distance of each part of the spiral portions 36b and 36b with respect to is constant, and the overall posture with respect to the developing sleeve 23 is always constant. As shown in FIG. 9, there is no change in the capacitance during the stirring cycle T. Moreover, since the spiral portions 36b and 36b are composed of two pieces, the overall strength is high. However, since the number of spiral parts 36b and 36b is two, the capacitance is
12p when 200g of toner is put in the developing container 25
When the toner was F and the toner was 0 g, it was 6 pF. Therefore, the detection level was set to 8.5 pF. <Embodiment 1 of the Second Invention> FIG. 15 shows Embodiment 1 of the second invention. The same components and functions as those of the first invention are designated by the same reference numerals and the description thereof will be omitted.

The developing device 21 of the present invention is provided with a telescopic electrode 37 which can freely expand and contract, and an interlocking mechanism 39 for expanding and contracting the elastic electrode 37. The expansion / contraction electrode 37 is formed in a crank shape, and is arranged substantially along the axial direction of the developing sleeve 23.
The magnet 37b is fixed to one end of the crank bar 7a, and a cylindrical tubular member 37c is arranged on the other end of the crank bar so as to be able to move in and out. The outer end of the cylindrical member 37c is fixed to the developing container 25.

The interlocking mechanism 39 has a switching rod 39a having a magnet 39b at its upper end, and a swing shaft 39c for swingably supporting the switching rod 39b in the arrow direction. Swing axis 3
The lower end of 9c is adapted to be engaged with and disengaged from a slide 7a which laterally protrudes from the side portion of the paper feed cassette 7 containing the transfer material. Further, a convex portion 7b is fixed to the other side portion of the paper feeding cassette 7, and the paper feeding cassette sensor 40 detects the position of the convex portion 7b, whereby the transfer material in the paper feeding cassette 7 is prevented. It is designed to detect the size. That is,
The slide 7a and the convex portion 7b are respectively formed in a predetermined shape and position according to the size of the transfer material in the paper feed cassette 7. A partition plate 7c for regulating one side of the transfer material and a separation claw 7d for separating the uppermost transfer material at the time of paper feeding are provided inside the paper feeding cassette 7.

Next, referring to FIGS. 16 and 17, when the B5 size transfer material is used, and when referring to FIGS. 18 and 19, the B4 size transfer material is used, the expansion / contraction electrode 3
7 and the operation of the interlocking mechanism 39 will be described.

In FIG. 16, the paper feed cassette 7 for B5 is used.
Is inserted into the main body 2 of the copying machine 1, the lower end of the switching rod 39a is pushed by the slide 7a, and swings in the direction of the arrow around the swing shaft 39c. Then, the switching rod 39a
The magnet 39b at the upper end of the
Press b. By this movement, the crank rod 37a is pushed into the tubular member 37c. The B5 paper feed cassette 7 has a B5 size transfer material fixed thereto by a partition plate 7c and separation claws 7d. Further, the sheet feeding cassette 7 for B5 is detected by the sheet feeding cassette sensor 40 at the position of the convex portion 7b.

FIG. 17 shows the expansion / contraction electrode 37 and the developing sleeve 2.
It is the figure which looked at the longitudinal direction relation of 3 from the upper part. Telescopic electrode 3
In No. 7, the portion corresponding to the B5 width is close to the developing sleeve 23, and the electrostatic capacitance between the expansion electrode 37 and the developing sleeve 23 is substantially determined by the portion corresponding to the B5 width.

On the other hand, FIG. 18 shows a paper feed cassette 41 for B4.
The slide 4 is shown in FIG.
By 1a, the switching rod 39a swings in the direction of the arrow in the direction opposite to that in FIG. 16, and the telescopic electrode 37 is pushed through the magnet 39b. Note that 41d is a separation claw, and that the sheet feeding cassette 41 for B4 is detected by the sheet feeding cassette sensor 40 at the position of the convex portion 41b.

FIG. 19 shows the expansion / contraction electrode 37 and the developing sleeve 2.
It is the figure which looked at the longitudinal direction relation of 3 from the upper part. Telescopic electrode 3
In No. 7, the portion corresponding to the B4 width is close to the developing sleeve 23, and the electrostatic capacitance between the expansion / contraction electrode 37 and the developing sleeve 23 is substantially determined by the portion corresponding to the B4 width, which is substantially the entire length of the developing sleeve 23. It

Now, when toner is put into the developing container 25 of the developing device 21 and B5 and B4 papers are continuously printed, the relationship between the residual toner amount in the developing container 25 and the electrostatic capacity is as shown in FIG. Become. A state in which the expansion / contraction electrode 37 is shortened as shown in FIG. 17 corresponds to the B5 capacitance, and a state in which the expansion / contraction electrode 37 is extended as shown in FIG. 19 corresponds to the B4 capacitance.

In the state of FIG. 17, the electrostatic capacity is 13 pF when the remaining toner amount is 48 g or more, and B5 size paper is continuously printed. When the remaining amount is 19 g or less, the electrostatic capacity decreases to 9 pF. Therefore, if the detection level is set to 12 pF for the B5 sheet passing by the signal of the sheet feeding cassette sensor 40, even if the toner of the B5 sheet is continuously printed and the toner amount of the B5 portion is reduced, the remaining toner amount is 36 g. The remaining amount warning light turns on at.

On the other hand, in the state of FIG. 19, the toner remaining amount is 4
If it is 1g or more, the capacitance is 15pF, and if B4 size paper is continuously printed, if it is 7g or less, the capacitance is 11pF.
Decrease to. Therefore, if the detection level is set to 14 pF for the B4 paper feed by the signal of the paper feed cassette sensor 40, the toner of the B4 paper continues to be printed and the toner decreases in the entire longitudinal direction of the developing sleeve 23, and the toner remaining amount remains. The remaining amount warning light is turned on when the amount is 28 g.

As described above, the expansion / contraction electrode 37 is interlocked with the paper feed cassette 7 or the paper feed cassette 41 through the interlocking mechanism 39, and the left and right widths (paper passing widths) of the transfer material in the respective paper feed cassettes 7 and 41 are passed. By matching the sensitivity of the electrostatic capacity with the developing sleeve 23, the remaining toner amount warning lamp can be turned on before the white spot in the image for each paper size. <Second Embodiment of Second Invention> Next, a second embodiment of the present invention will be described with reference to FIG.
1, FIG. 22, and FIG. 23. In these figures, the same members as those already described are designated by the same reference numerals and the description thereof will be omitted.

In the embodiment shown in FIG. 21, the transfer material is manually fed instead of being fed by the paper feed cassette. The transfer material is taken out from the manual feed tray 42 by the paper feed roller 9, and the taken out transfer material is conveyed along the guide member 10 between the photosensitive drum 19 and the transfer corona discharger 11. There is a paper size sensor 43 in between, and if this paper size sensor 43 does not shake, B5 size,
When shaken, it is detected as B4 size.

22 and 23 show the paper size sensor 43.
And the expansion / contraction electrode 37 will be described. Figure 2
In FIG. 23 and FIG. 23, the electrode expansion / contraction device 45 expands / contracts the expansion / contraction electrode 37 by rotating the rollers 45a forward and backward in response to the signal from the paper size sensor 43.

The operation of FIGS. 22 and 23 will be described below with reference to FIG.
This will be described with reference to the flowchart of. First, it is determined whether the paper size sensor 43 is shaken after the paper is fed (S1) according to the rotation signal of the paper feed roller 9 (S2). If it does not shake, since B5 size paper is fed as shown in FIG. 22, the roller 45a of the electrode expansion / contraction device 45 rotates in the direction of the arrow to contract the expansion / contraction electrode 37, and the developing sleeve 23.
The capacitance sensitivity with and is set to B5 width (S3). Further, the remaining amount warning light has a lighting level of 12 pF (S4), and
From the graph of 0, it turns on when it becomes 36 g or less (S5,
S6).

On the other hand, when the paper size sensor 43 is shaken (S2), since the B4 size paper is fed as shown in FIG. 23, the roller 45a of the electrode expansion / contraction device 45 rotates in the direction of the arrow. Extending the stretchable electrode 37, the developing sleeve 23
The capacitance sensitivity of and is set to the entire B4 width (S7). Further, the level of the remaining amount warning lamp is also set to 14 pF (S8), and
From the graph of 0, it turns on when it becomes 28 g or less (S9,
S6).

As described above, the sensitivity of the telescopic electrode 37 can be adjusted to the paper size even when there is no paper feed cassette and the paper is manually fed. <Embodiment 3 of the Second Invention> Furthermore, Embodiment 3 of the present invention is shown in FIGS. 25 and 26. This embodiment is the first embodiment,
A switchable electrode 46 is used instead of the two expandable electrodes 37. The switchable electrode 46 has a plurality of moving electrodes 46b and 46c having different lengths, and when B5 size paper is passed by the semi-rotating device 47 about the rotation shaft 46a, as shown in FIG. The moving electrode 46b having a width of B5 faces the developing sleeve 23. Further, when a B4 size paper is passed, the half-rotating device 47 halves the entire switchable electrode 46 so that the moving electrode 46c having a width of B4 faces the developing sleeve 23 as shown in FIG. Rotate.

In this way, by changing the sensitivity of the electrostatic capacity according to the paper size, the remaining toner amount can be accurately detected regardless of the paper size. <Embodiment 4 of the Second Invention> FIG. 27 shows Embodiment 1 of the third invention. The same components and functions as those described above are designated by the same reference numerals, and the description thereof will be omitted.

In this embodiment, a split electrode 49 is provided as an electrode facing the developing sleeve 23. Split electrode 49
As shown in FIG. 28, there is a metal electrode portion 49c having a width of B5 size, an insulating portion 49b beside the electrode portion 49c, and B5
The electrode portion 49a is provided outside the size (non-sheet passing portion).
The electrode portion 49a and the electrode portion 49c are insulated by the insulating portion 49b. The electrode portion 49c is directly connected to the remaining amount detecting means 50, while the electrode portion 49a is connected to the remaining amount detecting means 50 via the switch 51.

In FIG. 27, the paper feed cassette 7 for B5
When is inserted into the main body 2, the position of the convex portion 7b is detected by the paper feed cassette sensor 40 as the paper feed cassette 7 for B5. Then, in FIG. 28, the switch 51 is turned off mechanically or electrically (any method may be used), and the electrode portion 49a outside the B5 size (non-sheet passing portion) is formed.
Is disconnected from the remaining amount detecting means 50, and the remaining amount detecting means 50 measures the capacitance of only the electrode portion 49c.

That is, in the divided electrode 49, the portion corresponding to the width B5 forms the developing sleeve 23 and the capacitor,
The electrostatic capacitance between the divided electrode 49 and the developing sleeve 23 is a portion corresponding to the B5 width.

On the other hand, in FIG. 29, when the B4 paper feed cassette is inserted into the main body 2 in FIG. 27, the switch 51 is turned on.
N, the electrode portion 49a is electrically connected to the remaining amount detecting means 50, and the remaining amount detecting means 50 measures the electrostatic capacitance of the electrode portion 49a and the electrode portion 49c.

That is, in the divided electrode 49, the portion corresponding to the B4 width forms a capacitor with the developing sleeve 23,
The electrostatic capacitance between the divided electrode 49 and the developing sleeve 23 is a portion corresponding to the B4 width.

Now, the developing container 25 shown in FIGS. 28 and 29.
When toner is added to the paper and B5 and B4 papers are continuously printed, the relationship between the residual toner amount in the developing container 25 and the electrostatic capacity is as shown in FIG. In the state of FIG. 28, B
5 becomes the electrostatic capacity, and in the state of FIG. 29, it becomes the B4 electrostatic capacity.

In FIG. 28, the electrostatic capacity is 13 pF when the remaining amount of toner is 48 g or more, and B5 size paper is continuously printed. When the remaining amount is 19 g or less, the electrostatic capacity is reduced to 9 pF. Therefore, according to the signal from the paper feed cassette sensor 40, B
If the detection level is set to 12 pF for 5 sheets,
Even if the B5 paper is continuously printed and the toner is partially reduced in B5, the remaining amount warning lamp is turned on when the remaining amount of toner is 36 g.

On the other hand, in FIG. 29, when the remaining amount of toner is 41 g or more, the electrostatic capacity is 15 pF, and B4 size paper is continuously printed, and when it is 7 g or less, the electrostatic capacity is reduced to 11 pF. Therefore, if the detection level is set to 14 pF for the B4 sheet passing by the signal of the sheet feeding cassette sensor 40, the B4 sheet is continuously printed and the toner is developed by the developing sleeve 2.
3 is reduced in the entire longitudinal direction, and the remaining amount warning lamp is turned on when the remaining amount of toner is 28 g.

As described above, the divided electrode 49 is connected to the switch 5
If the sensitivity of the electrostatic capacity of the developing sleeve 23 is adjusted to the sheet passing width of each sheet feeding cassette by interlocking with the sheet feeding cassette 1 through 1, the toner remaining amount warning lamp is turned on before the white spot in the image for each sheet size. Can be made. <Fifth Embodiment of Second Invention> Next, a fifth embodiment of the present invention will be described with reference to FIG.
0, FIG. 31, and FIG. In this embodiment, the transfer material is fed manually without using a paper feed cassette. In addition, the same members as those explained so far,
The same reference numerals are given and the description thereof is omitted.

In FIG. 30, the switch 51 is turned on and off according to the signal from the paper size sensor 43 to change the electrostatic capacitance range of the divided electrode 49.

The divided electrodes 49 shown in FIGS. 30 and 31 will be described below.
Operations such as the above will be described with reference to the flowchart of FIG. First, it is determined whether or not the paper size sensor 43 is shaken after the paper is fed (S11) in accordance with the rotation signal of the paper feed roller 9 (S12). If it does not shake, it means that B5 size paper was fed as shown in FIG.
When the switch is turned off (S13), the electrode part 49a becomes the insulating part 4
Since it is insulated from the electrode portion 49c by 9b, the capacitance sensitivity with the developing sleeve 23 is B5 width. further,
The level of the remaining amount warning light is also set to 12 pF (S14), and FIG.
From the graph of No. 36, the light turns on when the weight is 36 g or less (S15,
S16).

On the other hand, when the paper size sensor 43 is shaken (S12), since the B4 size paper is fed as shown in FIG. 31, the switch 51 is turned on (S1).
7), the electrode portion 49a is electrically connected to the remaining amount detecting means 50, and the capacitance sensitivity is in the entire B4 width. Furthermore, the level of the remaining amount warning light is also set to 14 pF (S18), and from the graph of FIG.
It lights up when the weight is 28 g or less (S19, S16).

As described above, the sensitivity of the divided electrode 49 can be adjusted to the paper size even when there is no paper feed cassette and the paper is manually fed.

In the description of the first invention and the second invention, the maximum sheet passing size is B4 as an example.
The same applies to the case of No. 3. <Embodiment 1 of the Third Invention> FIG. 33 shows a developing device 21 according to the present invention housed in a cartridge container 18, a photosensitive drum 19 and a corona discharger 2 in the cartridge container 18.
No. 0, the cleaning device 22 and the like, and the cartridge container 18 is detachably attached to the apparatus main body (not shown). The developing device 21 in the form of a cartridge is similar to the developing device 21 described above (first or second invention) in that the developing sleeve 23 causes toner to be applied to the electrostatic latent image formed on the photosensitive drum 19. Is attached to form a toner image.

In the developing device 21 described above, reference numeral 25 is a developing container for storing magnetic toner, and a developing sleeve 23 having a built-in magnet roll is provided at a lower opening 25b thereof with the photosensitive drum 19 and a predetermined opening. They are arranged at a distance, and carry and carry toner by rotating. Further, a blade 26 which is in contact with the developing sleeve 23 and forms a layer of toner in a predetermined thickness is provided.
At the bottom of the developing container 25, the developing sleeve 23 is horizontally provided.
An inclined surface 52 is formed which rises with increasing distance from. Further, the toner inside the developing container 25 is agitated,
A stirring member 27 for sending the developing sleeve 23 toward the developing sleeve 23.
a and 27b are provided. These stirring members 27a,
27b is formed by a rod-shaped member having a diameter of about 2 mm,
The toner is moved toward the developing sleeve 23 by being rotationally driven in the arrow direction by a drive mechanism (not shown). The agitating member 27a makes a large rotation in the developing container 25, while the agitating member 27b makes a small rotation near the developing sleeve 23, and the agitating members 27a and 27b work together to direct the toner toward the developing sleeve 23. Move effectively. The radius of rotation, the rotation speed, etc. of the stirring members 27a, 27b may be appropriately determined depending on the shape of the developing container 25, the characteristics of the toner, and the like.

A remaining amount detecting means is provided to warn that the cartridge container 18 needs to be replaced when the amount of toner in the developing container 25 becomes small. The remaining amount detecting means 53 includes a sheet-shaped conductive rubber (conductive member) 53a and electrodes 53b and 53b sandwiching the front surface and the back surface of the conductive rubber 53a, and is laid on the inclined surface 52 as a whole. Then, the upper and lower electrodes 53b,
The remaining amount of toner is detected by monitoring the resistance R1 between 53b. The relationship between the resistance R1 and the remaining amount of toner in the developing container 25 has a characteristic as shown in FIG.
These relationships correspond to each other at least when the remaining amount of toner is 200 g or less, and therefore the remaining amount of toner can be detected by detecting the resistance R1. In the developing device 21 of this embodiment, the remaining amount detecting means 5
Immediately after the toner is exhausted on No. 3, there is a little toner (about 30 g) in the vicinity of the developing sleeve 23. "Warning" is displayed. That is, the electrodes 53b, 53 of the remaining amount detecting means 53
When the resistance value between points b is R1 or more, the "toner out warning" is displayed. <Second Embodiment of Third Invention> FIG. 35 shows a second embodiment of the present invention. In this embodiment, the remaining amount detecting means 53 provided on the inclined surface 52 of the developing container 25 of the developing device 21 is movable along the inclination direction of the inclined surface 52. With such a configuration, the remaining amount detecting means 53 reciprocates toward and away from the developing sleeve 23, thereby moving the toner in the developing container 25 toward the developing sleeve 23. Can be made. That is, the remaining amount detecting unit 53 is formed in a structure in which the front and back surfaces of the conductive rubber are sandwiched between the electrodes and detects the resistance between the front and back electrodes, in the same manner as in the first embodiment.
It also functions as a stirring member that moves the toner toward the developing sleeve 23. The details will be described below.

The remaining amount detecting means 53 is connected to a driving means (not shown) with free movement. As the driving means reciprocates in the direction of the arrow by a driving device (not shown), the remaining amount detecting means 53 tilts. Reciprocates along surface 52.
When the remaining amount detecting means 53 approaches the developing sleeve 23, the developing sleeve 23 rotates to move the toner, and the end of the remaining amount detecting means 53 reaches the region where the toner is carried and conveyed by the developing sleeve 23. . by this,
The toner can be used up without leaving the toner in the developing container 25.

As in the first embodiment, the remaining amount detecting means 5
Since the toner amount on 3 and the resistance value between the electrodes have the relationship as shown in FIG. 34, when the detected resistance value becomes R1 or more, the "toner absence warning" is displayed.

According to the present embodiment, the plate-like remaining amount detecting means 53 reciprocates along the inclined surface 52 to move the toner toward the developing sleeve 23, whereby the inside of the developing container 25 is moved. The toner is supplied to the developing sleeve 23 without remaining, and it becomes possible to detect the absence of toner. As a result, the number of components of the developing device 21 can be reduced, the operational reliability can be improved, and the cost can be reduced. <Third Embodiment of the Third Invention> In this embodiment, as shown in FIG. 36, a plurality of remaining amount detecting means 53A and 53B are provided to improve the detection accuracy of the remaining amount of toner. The basic configuration and operation are the same as in the first embodiment. Remaining amount detecting means 53
A and 53B are arranged on the inclined surface 52 of the developing container 25 and near the developing sleeve 23. Two remaining amount detecting means 53
The resistances of A and 53B are checked respectively, and when both the remaining amount detecting means 53A and 53B reach the toner-free level, a "toner-free warning" is displayed. by this,
The remaining toner amount can be detected more reliably. <Embodiment 4 of Third Invention> In this embodiment, as shown in FIG. 37, the present invention is applied to a toner replenishing type developing device 21. As in the third embodiment, two remaining amount detecting means 53A and 53B are arranged. When the remaining amount detecting means 53A is at the toner-free level and the remaining amount detecting means 53B is at the toner-containing level, toner is supplied from the toner supply hopper 55. As a result, the toner can be reliably replenished with the toner in the developing container 25 being in a predetermined amount, so that the change in the image density during the replenishment can be reduced.

[0072]

As described above, according to the present invention,
It has the following effects. <Effect of the first invention> According to the first invention, since the stirring member arranged in parallel with the developer carrying member has a spiral portion, the stirring member is rotated to rotate the developer carrying member. It is possible to effectively stir the toner along the axial direction, and it is possible to eliminate the toner density unevenness in the horizontal direction of the final image. Furthermore, when the stirring member is used as a remaining amount detecting means based on detecting the electrostatic capacity between the stirring member and the developer carrying member, the stirring member is always attached to the developer carrying member regardless of its rotation. Since the same attitude can be maintained, the electrostatic capacity does not change depending on the rotation cycle if the remaining amount of toner is the same, and the remaining amount of toner and the electrostatic capacity have a one-to-one correspondence. Therefore, the remaining amount of toner can be accurately detected by detecting the capacitance. <Effect of the Second Invention> According to the second invention, the expansion electrode, the moving electrode, and the divided electrode that face the developer carrier and detect the electrostatic capacitance between the developer carrier and the developer carrier are provided via an interlocking mechanism or the like. Thus, it is possible to set a suitable state according to the left-right width (sheet passing width) of the transfer material, and therefore it is possible to perform good residual amount detection that is suitable for the usage state of the transfer material, that is, the toner consumption state. <Effect of the third invention> According to the third invention, the remaining amount of toner is provided by a simple structure in which the remaining amount detecting means in which the front and back of a sheet-shaped conductive member are sandwiched by electrodes is laid on the inclined surface of the developing container. Can be accurately detected, so that it is easy to simplify the entire structure of the developing device and promote miniaturization.

[Brief description of drawings]

FIG. 1 is a sectional view showing the outline of an image forming apparatus according to a first embodiment of the first invention.

FIG. 2 is an enlarged sectional view of the developing device.

FIG. 3 is a perspective view showing the structure of the remaining amount detecting means.

FIG. 4 is a view taken along line A of FIG.

FIG. 5 is a diagram showing an equivalent circuit of the same.

FIG. 6 is a diagram showing a relationship between a stirring cycle and a capacitance of the stirring member.

FIG. 7 is a diagram showing a relationship between the remaining toner amount and electrostatic capacity.

FIG. 8 is a perspective view showing the configuration of the remaining amount detecting means according to the second embodiment of the first invention.

FIG. 9 is a diagram showing a relationship between a stirring cycle and a capacitance of the stirring member.

FIG. 10 is a cross-sectional view showing a developing device according to Related Art 1.

FIG. 11 is a diagram showing an equivalent circuit of the same.

FIG. 12 is a sectional view showing the developing device in the same manner.

FIG. 13 is a perspective view showing the structure of the remaining amount detecting means.

FIG. 14 is a diagram showing the relationship between the stirring cycle and the capacitance of the stirring member.

FIG. 15 is a sectional view showing the outline of the image forming apparatus according to the first embodiment of the second invention.

FIG. 16 is an operation explanatory view of the expandable electrode when the transfer material is B5.

FIG. 17 is a top view of the stretchable electrode when the transfer material is B5.

FIG. 18 is an operation explanatory diagram of the expansion / contraction electrode when the transfer material is B4.

FIG. 19 is a top view of the stretchable electrode when the transfer material is B4.

FIG. 20 is a diagram showing a relationship between the remaining toner amount and the electrostatic capacity.

FIG. 21 is a sectional view showing the outline of an image forming apparatus according to Embodiment 2 of the second invention.

FIG. 22 is an operation explanatory view of the expandable electrode when the transfer material is B5.

FIG. 23 is an operation explanatory view of the expandable electrode when the transfer material is B4.

FIG. 24 is a flowchart of the same.

FIG. 25 is an operation explanatory view of the moving electrode according to the third embodiment of the second invention.

FIG. 26 is an explanatory view of the operation of the moving electrode.

FIG. 27 is a sectional view showing the outline of an image forming apparatus according to Embodiment 4 of the second invention.

FIG. 28 is an operation explanatory view of the divided electrodes when the transfer material is B5.

FIG. 29 is an explanatory view of the operation of the divided electrodes when the transfer material is B4.

FIG. 30 is an operation explanatory view of the divided electrodes when the transfer material of Example 5 of the second invention is B5.

FIG. 31 is an explanatory view of the operation of the divided electrodes when the transfer material is B4.

FIG. 32 is a flowchart of the same.

FIG. 33 is a sectional view of the process cartridge according to the first embodiment of the third invention.

FIG. 34 is a diagram showing a relationship between the remaining toner amount and resistance.

FIG. 35 is a sectional view showing a developing device according to Embodiment 2 of the third invention.

FIG. 36 is a sectional view showing a developing device of Embodiment 3 of the third invention.

FIG. 37 is a sectional view showing a developing device according to Embodiment 4 of the third invention.

FIG. 38 is a sectional view of a process cartridge according to Related Art 2.

[Explanation of symbols]

 19 image carrier (photosensitive drum) 23 developer carrier (developing sleeve) 25 developing container 25b lower opening 29 stirring means (stirring member) 29a rotating shaft 29b spiral part 29c closest part 30, 53 remaining amount detecting means 37 expansion and contraction Electrode 39 Interlocking mechanism 46b, 46c Moving electrode 47 Moving mechanism (semi-rotating device) 49 Split electrode 52 Inclined surface 53a Conductive member (conductive rubber) 53b Electrode

Claims (6)

[Claims] 1. A developer container containing a developer, a developer carrier rotatably arranged at a lower opening of the developer container and supplying the developer to an image carrier, and the inside of the developer container. In a developing device comprising a rotatable stirring means for moving the developer toward the developer carrier and a remaining amount detecting means for detecting the remaining amount of the developer in the developing container, the stirring means A spiral having a rotation axis parallel to the developer carrier and a spiral surrounding the rotation shaft and having a certain number of closest parts to the developer carrier regardless of the rotation of the stirring means. A developing unit, wherein the remaining amount detecting unit detects the electrostatic capacitance between the closest portion of the stirring unit and the developer carrying member. 2. A developer container containing a developer, a developer carrier rotatably arranged at a lower opening of the developer container and supplying the developer to an image carrier, and the inside of the developer container. And a remaining amount detecting means for detecting the remaining amount of the developer, the remaining amount detecting means is opposed to the developer carrying member and expands and contracts in the left-right width direction of the transfer material to be image-formed. Includes a flexible electrode and a interlocking mechanism that expands and contracts the expansion electrode according to the lateral width of the transfer material, and detects the electrostatic capacitance between the expansion electrode and the developer carrier after expansion and contraction. A developing device characterized by: 3. A developer container containing a developer, a developer carrier rotatably arranged at a lower opening of the developer container and supplying the developer to an image carrier, and the inside of the developer container. In a developing device provided with a remaining amount detecting means for detecting the remaining amount of the developer, the remaining amount detecting means, a plurality of moving electrodes arranged so as to be able to contact and separate toward the developer carrier, A moving mechanism for moving the moving electrode at a position corresponding to the left and right width of the transfer material, which is an image forming object, to the developer carrier, and the moving electrode approaching the developer carrier and the image carrier. A developing device characterized by detecting the electrostatic capacitance between them. 4. A developer container containing a developer, a developer carrier rotatably disposed at a lower opening of the developer container and supplying the developer to an image carrier, and the inside of the developer container. In the developing device having a remaining amount detecting means for detecting the remaining amount of the developer, the remaining amount detecting means includes a divided electrode divided corresponding to the left and right width of the transfer material and a left and right width of the transfer material. A developing device, comprising: an interlocking mechanism that operates the divided electrodes of corresponding portions, and detects the electrostatic capacitance between the divided electrodes corresponding to the lateral width of the transfer material and the image carrier. . 5. A developing device, comprising: a developing container having an inclined surface which descends toward a lower opening portion at a bottom portion; and a developer carrying member disposed in the opening portion; a sheet-shaped conductive member; A developing device, characterized in that a remaining amount detecting means having electrodes sandwiching the front and back of the conductive member is disposed on the inclined surface. 6. The developing device according to claim 5, wherein the remaining amount detecting means is disposed so as to be able to come into contact with and separate from the developer carrying member.