Patent Grant
9857730
Field of the Invention
The present invention relates to a developer container, a developing apparatus, a process cartridge, an apparatus main body, and an image forming apparatus. Here, a developing apparatus at least includes a developer bearing member that bears developer. Alternatively, a developing apparatus may also include a frame body for housing developer (developer container), a conveying member for conveying the developer, and the like. A cartridge is a piece of equipment which integrates a plurality of components in an image forming apparatus and which is attachable/detachable to/from a main body of the image forming apparatus. A process cartridge at least includes an image bearing member that bears a developer image. In particular, a cartridge which is obtained by integrating an image bearing member and processing means that acts on the image bearing member is referred to as a process cartridge. An image forming apparatus is an apparatus which forms an image on a recording material (transferred material) and is, more specifically, an image forming apparatus such as a copier, a printer, and a facsimile apparatus using an electrophotographic system or an electrostatic recording system.
Description of the Related Art
Conventionally, an image forming apparatus adopting the electrophotographic system is provided with a developing apparatus which forms a developer image by supplying developer to an electrostatic latent image formed by scanning exposure of an image bearing member. In addition, in recent years, there have been many cases where a developing apparatus, an image bearing member, and processing means (charging member and the like) are integrated as a process cartridge. By integrating a plurality of members as a process cartridge and making the process cartridge attachable/detachable to/from an apparatus main body of an image forming apparatus, maintenance work including replenishing developer can be readily performed.
In such a process cartridge system, when developer runs out, images can be formed once again by having a user replace the cartridge or replenish the developer. Therefore, such an image forming apparatus generally includes means for detecting consumption of developer and notifying the user of a placement timing, or in other words, developer amount detecting means. As an example of such developer amount detecting means, Japanese Patent Application Laid-open No. 2001-117346 proposes a plate antenna system which includes a pair of input-side and output-side electrodes and which detects a developer amount by measuring a capacitance between both electrodes.
In addition, Japanese Patent Application Laid-open No. 2003-248371 and Japanese Patent Application Laid-open No. 2007-121646 propose configurations in which a developer bearing member is regarded as an input-side electrode due to application of an AC bias to the developer bearing member and a capacitance detecting portion as an output-side electrode is provided at a location opposing the developer bearing member in a developing apparatus. All of these documents describe systems which detect a developer amount using a change in capacitance that occurs when an amount of developer between a pair of input and output electrodes changes.
As demonstrated in the configurations described in these documents, since developer amount detection is required to be particularly accurate when only a small amount of the developer remains, a detecting portion must at least be provided at a location where the developer amount changes when the developer is just about to run out. However, when a detecting portion is provided in a container in which developer is stirred by a stirring member, in particular, a state of the developer does not stabilize because the developer is being stirred. Therefore, it is difficult to detect a developer amount with accuracy.
An object of the present invention is to provide a technique capable of improving accuracy of developer amount detection using a stirring member and electrodes provided in a developer housing chamber.
Another object of the present invention is to provide a developer container comprising:
a housing chamber which includes an opening and which houses developer;
a stirring member which includes a sheet-like stirring portion and a rotary shaft to which the stirring portion is attached; and
a first electrode and a second electrode which are used to detect an amount of the developer and which are arranged with an interval therebetween, wherein
an area between the first electrode and the second electrode in the housing chamber is positioned below the rotary shaft of the stirring member, and
the sheet-like stirring portion comes into contact with the area due to rotation of the stirring member.
Another object of the present invention is to provide an apparatus main body of an image forming apparatus to which a cartridge including a housing chamber that houses developer and a plurality of electrodes used to detect an amount of the developer in the housing chamber is mounted and which forms an image on a recording material, wherein
a plurality of types of the cartridges with different numbers of the electrodes are configured to be attachable/detachable to the apparatus main body,
the apparatus main body comprises a terminal that electrically connects to the electrodes when the cartridge is mounted to the apparatus main body, and
the terminal is provided in a number equal to or greater than a largest number among the numbers of the electrodes respectively included in the plurality of types of the cartridges.
Another object of the present invention is to provide an image forming apparatus that forms an image on a recording material, comprising:
an apparatus main body;
a cartridge which includes a housing chamber that houses developer and electrodes used to detect an amount of the developer in the housing chamber and which is configured to be attachable/detachable to/from an apparatus main body; and
a terminal which electrically connects the electrodes and the apparatus main body to each other when the cartridge is mounted to the apparatus main body, wherein
the apparatus main body is configured such that a plurality of types of the cartridges with different numbers of the electrodes are attachable/detachable to the apparatus main body, and
the terminal is provided in the same number as a largest number among the numbers of the electrodes respectively included in the plurality of types of the cartridges.
According to the present invention, accuracy of developer amount detection using a stirring member and electrodes provided in a developer housing chamber can be improved.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).
Modes for implementing the present invention will now be exemplarily described in detail based on embodiments with reference to the drawings. It is to be understood that dimensions, materials, shapes, relative arrangements, and the like of components described in the embodiments are intended to be changed as deemed appropriate in accordance with configurations and various conditions of apparatuses to which the present invention is to be applied. In other words, the scope of the pre sent invention is not intended to be limited to the embodiments described below.
<Outline of Configurations and Operations of Image Forming Apparatus and Process Cartridge>
Based on a print start signal, the photosensitive drum 120 is rotationally driven clockwise in a direction of an arrow R11 at a circumferential speed (process speed) of 147.6 mm/s. A charging roller that is the charging apparatus 130 to which a charging bias is applied is brought into contact with the photosensitive drum 120. The charging roller 130 is rotationally driven in accordance with the rotation of the photosensitive drum 120. A circumferential surface of the rotating photosensitive drum 120 is uniformly charged to a predetermined polarity and potential by the charging apparatus 130. In the present embodiment, the circumferential surface of the rotating photosensitive drum 120 is charged to a predetermined negative potential. While the charging apparatus 130 in the present embodiment is a contact-charging charging roller, depending on the configuration, a non-contact charging member or a contact charging brush can be used.
A laser scanning exposure of image information is performed by an exposing apparatus (laser scanner unit) 103 on a charged surface of the photosensitive drum 120. Laser light output from the exposing apparatus 103 enters the cartridge and exposes the surface of the photosensitive drum 120. Potential of a portion of the photosensitive drum surface irradiated by the laser light (exposed bright portion) attenuates and an electrostatic latent image (or an electrostatic image) corresponding to the image information is formed on the photosensitive drum surface. The present embodiment adopts an image exposure system which exposes an image information portion. An LED or the like can be used as a light source for exposure. The electrostatic latent image is developed by toner T on a developing sleeve (or a developing roller) 141 as a developer bearing member of the developing apparatus 140.
Meanwhile, a pickup roller 105 of a sheet tray member 104 is driven at a predetermined control timing and one sheet of recording material (paper) that is recording media stacked and housed in the sheet tray member 104 is separated and supplied. As the recording material passes a transfer roller 107 (a transfer nip member where the photosensitive drum 120 and the transfer roller 107 come into contact with each other) via a transfer guide 106, a toner image on the surface of the photosensitive drum 120 is electrostatically transferred onto a surface of the recording material. Subsequently, the recording material that is a transfer material is subjected to a heat and pressure fixing process of the toner image at a fixing apparatus 109 and discharged to a paper discharge tray 111. Residue such as untransferred toner remains on the surface of the photosensitive drum 120 after separation of the sheet material. The residue is removed and cleaned by the cleaning apparatus 150 to be once again repeatedly used for image formation starting from charging.
<Developing Apparatus>
A magnetic single component toner T in the toner chamber is conveyed by a stirring member 160 to the developing chamber through a toner supply opening 145 that is a communication opening provided between the developing chamber 146 and the toner chamber 147. The toner T in the developing chamber 146 is drawn to a surface of the developing sleeve 141 by a magnet that is a magnetic body enveloped by the developing sleeve 141. Subsequently, with the rotation of the developing sleeve 141 in a direction of R12, the toner T is conveyed in a direction of a developing blade 142 constituted by an elastic member. Then, the toner T is subjected to triboelectricity impartation and layer thickness restriction by the developing blade 142 and conveyed on the surface of the developing sleeve 141 in a direction of the photosensitive drum 120. While a magnetic single component toner is used in the present embodiment, depending on the configuration, a two component toner or a nonmagnetic toner may be used instead.
In this case, a developing bias obtained by superimposing an AC voltage (peak-to-peak voltage=1500 Vpp, frequency f1=2400 Hz) on a DC voltage (Vdc=−400 V) is applied to the developing sleeve 141 from the image forming apparatus main body and the photosensitive drum 120 is grounded. Since an electric field is generated in an area where the photosensitive drum 120 and the developing sleeve 141 oppose each other, a latent image on the surface of the photosensitive drum 120 is developed by the charged toner T described earlier. A developing method is not limited to this method and, depending on the configuration, contact developing may be performed instead.
<Developer Container Enabling Detection of Developer Amount>
Next, a developer container according to the first embodiment will be described with reference to
The antenna member 143 and the antenna member 144 need only have conductive properties and, in the present embodiment, are configured such that a conductive sheet is integrated with a container frame body by insert molding. However, this configuration is not restrictive and other conductive members may be used instead. For example, a conductive resin sheet in which a resin is imparted with conductive properties may be used. In this case, since a sheet shape of a conductive resin sheet can be readily changed during molding and the like, various shapes can be accommodated. For example, as in the case of the present embodiment, a conductive resin sheet can be arranged on a curved surface or a semicircular surface. In addition, if a frame body is made of resin, since a conductive resin sheet is also made based on resin, the frame body and the conductive resin sheet can be integrally formed and, since the frame body and the conductive resin sheet have similar rates of dimensional change due to a change in temperature, peeling and the like are less likely to occur than metal and the like. Furthermore, the antenna member 143 and the antenna member 144 are arranged with an interval therebetween along a container wall surface, and a distance (a distance along a wall surface in a rotating direction of the stirring member 160) of a gap X1 formed on the wall surface is set to 7 mm. In addition, the antenna member 143 and the antenna member 144 are arranged such that the gap X1 is positioned in an area including a lowermost location V10 of the wall surface of the toner chamber 147 in a vertical direction and at a position below a stirring shaft 160a of the stirring member 160. In
In this case, a bottom surface refers to a portion which is a lower wall surface area among areas opposing each other in a vertical direction on a wall surface forming the toner chamber 147 in the frame body of the developer container (an area opposing a ceiling area of the toner chamber 147) and on which the toner is mounted even if temporarily. In the present embodiment, as shown in
The stirring member 160 is constituted by the stirring shaft 160a and a stirring portion 160b that is a flexible sheet member. The stirring shaft 160a is rotatably supported by the container frame body and, with rotational driving of the stirring shaft 160a, the stirring portion 160b moves in the toner chamber 147 with the stirring shaft 160a as a rotational axis and stirs the toner T in the toner chamber 147. The stirring portion 160b is configured so that a tip side thereof slides against at least the bottom surface of the toner chamber 147 and also comes into sliding contact with the antenna members 143 and 144 installed on the bottom surface. The antenna members 143 and 144 and the gap X1 are arranged in an order of the antenna member 144, the gap X1, and the antenna member 143 in a rotating direction of the stirring portion 160b which is a direction of movement of the stirring portion 160b when positioned below the stirring shaft 160a. In the present embodiment, the antenna members 143 and 144 are configured to be exposed on the bottom surface and are in a contacting positional relationship with the stirring portion 160b. However, this configuration is not restrictive and, alternatively, a configuration may be adopted in which the antenna members are embedded inside a frame body constituting the bottom surface. In addition, a configuration may be adopted in which the antenna members are glued to a frame body constituting the housing chamber from the outside.
In the configuration according to the present embodiment, the toner supply opening is sealed by a sealing member 160c that is a sheet member to ensure that the toner T does not leak from the developing apparatus 140. While an unsealing member must be provided in the apparatus in order to unseal the sealing member 160c, in the present embodiment, the stirring member also functions as an unsealing member. Obviously, an unsealing member may be provided separately. A gear that is a drive transfer member attached to the developing apparatus receives drive force from the apparatus main body, and the stirring member that is the unsealing member receives the drive force received by the gear and rotates. Due to the rotation of the stirring member, the sealing member is wound around the stirring member and separated from the wall surface of the toner chamber and, consequently, the sealing member is unsealed.
In the present embodiment, the developing sleeve 141 and the antenna member 144 are used as members for applying an AC bias for detecting a remaining toner amount. However, a similar effect to the present embodiment may be obtained even when, for example, an AC bias is not applied to the developing sleeve 141. In addition, an AC bias may be applied to the antenna member 143 and the antenna member 144 may be used as a developer amount detecting portion. However, as in the present embodiment, a favorable arrangement involves arranging the antenna member 143 as a developer amount detecting portion between the developing sleeve 141 and the antenna member 144. Due to this arrangement and configuration, both a change in capacitance between the developing sleeve 141 and the antenna member 143 and a change in capacitance between the antenna member 144 and the antenna member 143 can be detected in an efficient manner.
<Detection of Developer Amount>
Next, validity of the present embodiment will be explained through a detailed description of the detection of a developer amount according to the present embodiment. As shown in
The present embodiment adopts a configuration in which a developer amount is detected using the fact that a change in a developer amount causes a changes in combined capacitance of capacitance between the antenna member 143 that acts as a developer amount detecting portion and the antenna member 143 and capacitance between the antenna member 143 and the developing sleeve 141. Therefore, when the toner T is stirred with rotational driving of the stirring member 160, a state of the toner in the area A1 changes and, even though the toner amount does not change, an output indicating an apparent change in the toner amount ends up being obtained at a rotational driving cycle of the stirring member 160.
In consideration thereof, in the present embodiment, a configuration is adopted which detects a developer amount by comparing an output value which is an integral multiple of a rotational cycle of the stirring member 160 or which corresponds to an average value of capacitance over a sufficiently long period of time with a relationship between an output value and a developer amount prepared in advance. The larger the amount of change in the output value per a unit amount of change in the toner amount or, in other words, the larger the amount of change in capacitance, the higher the accuracy of developer amount detection that can be performed. Conversely, for example, in a case where capacitance hardly changes even when the toner amount changes, the accuracy of developer amount detection can be assumed to be low.
In addition, generally, since one of the main purposes of performing developer amount detection is to provide the user with a guide for replacing the cartridge, accuracy is favorably high particularly when the amount of toner is small. Therefore, the present embodiment improves accuracy of developer amount detection in the case of a small toner amount by increasing a change in capacitance particularly when the amount of toner is small.
Meanwhile, a relationship between capacitance C1, and an area S and a distance d1 of two antenna members, are known to be described as follows.
C1=∈S/d1 Expression (1)
However, the antenna members according to the present embodiment are arranged along a wall surface of the toner chamber 147 and, for example, contribution to capacitance increases in an area where the distance d1 is shorter and contribution to capacitance decreases in an area where the distance d1 is longer.
Therefore, contribution to a change in capacitance is greater in a vicinity of the gap X1 shown in
To describe the state shown in
In the present embodiment, the antenna members 143 and 144 are arranged so that the gap X1 is formed in an area including a lowermost position (V) on the wall surface of the toner chamber 147. In this configuration, capacitance changes significantly even if the amount of toner having dropped from the stirring member 160 is extremely small. Therefore, this configuration is more favorable for detecting a remaining toner amount. However, the configuration described above is not restrictive since there are cases where an effect similar to the present embodiment can be obtained even though the gap X1 is somewhat deviated from the lowermost position (V) on the wall surface of the toner chamber 147 as long as the gap X1 is positioned approximately directly below the stirring shaft 160a.
<Verification of Improved Accuracy of Developer Amount Detection>
First, details of driving of the stirring member and capacitance according to the present embodiment will be described.
A cause of a fluctuation in capacitance that occurs in accordance with driving of the stirring member 160 will be described by determining a correspondence between the relationships shown in
As a first point, at a timing where the stirring portion 160b passes T11 in
As a second point, at a timing where the stirring portion 160b passes T12 in
As a third point, at a timing where the stirring portion 160b passes T13 in
As a fourth point, at a timing where the stirring portion 160b passes T14 in
As a fifth point, at a timing where the stirring portion 160b passes T15 in
Next, a description will be given on improving accuracy of developer amount detection particularly when the amount of toner is small by optimizing a positional relationship between the gap X1 and the stirring shaft 160a which is a feature of the present embodiment.
While vertical axes in
A second embodiment of the present invention differs from the first embodiment in a configuration of a developer container. Hereinafter, differences from the first embodiment will be described and matters that are similar to those of the first embodiment will not be described. It is to be understood that matters not described here are similar to those described in the first embodiment.
The bottom surface of the toner supply chamber 187 of the developing apparatus 180 according to the present embodiment is configured to have two depressed portions that are depressed downward in a vertical direction. The toner supply chamber 187 is configured so as to be approximately divided into an area near a toner supply opening 186 (a first housing area) and a depth-side area that is further away from the toner supply opening 186 (a second housing area) by a convex portion that protrudes upward in the vertical direction from the bottom surface between the two depressed portions.
The first stirring member 181 that is a stirring member is arranged in the first housing area in the toner supply chamber 187 and stirs toner in the first housing area so that the toner in the first housing area is supplied to the developing sleeve 141 via the toner supply opening 186. The first stirring member 181 includes a first stirring shaft 181a (first rotary shaft) and a sheet-like first stirring portion 181b.
The second stirring member 185 that is a stirring member is arranged in the second housing area in the toner supply chamber 187 and stirs toner in the second housing area so that the toner in the second housing area moves over the convex portion and into the first housing area. The second stirring member 185 includes a second stirring shaft 185a (second rotary shaft) and a sheet-like second stirring portion 185b.
The antenna member 182 (first electrode) is installed in the first housing area, the antenna member 184 (fourth electrode) is installed in the second housing area, and the antenna member 183 is installed so as to straddle the convex portion and extend in both the first housing area and the second housing area. On the bottom surface of the toner supply chamber 187, a gap X1 is formed between the antenna member 182 and a portion of the antenna member 183 on the side of the first housing area (second electrode) and a gap Y1 is formed between the antenna member 184 and a portion of the antenna member 183 on the side of the second housing area (third electrode). The developing sleeve 141 functions as a fifth electrode.
In the first housing area, the antenna members 182 and 183 and the gap X1 are arranged in an order of the antenna member 183, the gap X1, and the antenna member 182 in a direction of movement of the stirring portion 181b (from a distal side toward an opening side of the container) in an area below the stirring shaft 181a.
In the second housing area, the antenna members 183 and 184 and the gap Y1 are arranged in an order of the antenna member 184, the gap Y1, and the antenna member 183 in a direction of movement of the stirring portion 185b (from a distal side toward an opening side of the container) in an area below the stirring shaft 185a.
As shown in
As shown in
The developing apparatus 180 according to the present embodiment is configured so that a predetermined AV bias is applied to the antenna member 183 and the developing sleeve 141 from an AC power supply 145A. In addition, the antenna member 182 and the antenna member 184 are electrically connected to each other. Developer amount detection is performed using a change in combined capacitance of capacitance between the antenna member 182 and the portion of the antenna member 183 on the side of the first housing area, capacitance between the developing sleeve 141 and the antenna member 182, and capacitance between the antenna member 184 and the portion of the antenna member 183 on the side of the second housing area.
In the present embodiment, in a similar to the first embodiment, the stirring member 181 is configured to as to pass through the area A1 during rotational driving and the gap X1 is arranged below the stirring shaft 181a of the stirring member 181. In
is a diagram representing a relationship between a toner amount and an average value of capacitance according to the second embodiment. While a similar effect to the first embodiment is obtained in the present embodiment, the effect is simultaneously obtained at both the gap X1 and the gap Y1 in the present embodiment. The second embodiment differs from the first embodiment in that, when both the stirring member 181 and the stirring member 185 are rotationally driven, toner moves in both the area A1 and the area A2. Therefore, while the effect is obtained when the toner amount is at least 0 g to 40 g in the first embodiment, in the present embodiment, the effect can also be obtained in. for example, an area from 40 g to 200 g in addition to the area from 0 g to 40 g.
While the antenna members are arranged as shown in
In addition, while a vertical axis in
According to the present invention, a developer container, a developing apparatus, a process cartridge, and an image forming apparatus which enable a developer amount to be detected at high accuracy can be provided.
<Configuration of Image Forming Apparatus and Image Forming Process>
The image forming apparatus according to the present embodiment can be used by selectively mounting a cartridge A2 (
An opening/closing cover 2101 of the apparatus main body 2100 can open as depicted by a dot chain line around a hinge shaft member 2102 to open the apparatus main body 2100. This opening enables the cartridge A2 or the cartridge B2 to be inserted and mounted to a predetermined mounting position in the apparatus main body 2100 and, conversely, taken out and removed from the apparatus main body 2100 according to a predetermined procedure. By mounting the cartridge A2 or the cartridge B2 to the apparatus main body 2100, a state is created where the cartridge A2 or the cartridge B2 is mechanically and electrically coupled with the apparatus main body 2100. Accordingly, the image forming apparatus can form images.
The drum-type electrophotographic system (hereinafter, referred to as a photosensitive drum) 201 as an image bearing member is rotationally driven at a predetermined rotational speed in a direction of an arrow R21 based on a print start signal. The charging roller 202 that applies a charging bias is brought into contact with the photosensitive drum 201, and a circumferential surface of the rotating photo sensitive drum 201 is uniformly charged to a predetermined polarity and potential by the charging roller 202 (charging step). With respect to the charged surface, laser scanning exposure of image information is performed by exposing means (hereinafter, referred to as a scanner) 203. The scanner 203 outputs laser light modulated in correspondence to an electric signal of image information input from a host apparatus to perform scanning exposure of the charged surface of the photosensitive drum 201 and, as a result, an electrostatic latent image (electrostatic image) made up of a bright area potential portion and a dark area potential portion is formed on the circumferential surface of the photosensitive drum 201 (exposing step). The electrostatic latent image is developed by a developing sleeve 204 (developer bearing member) of the developing apparatus 211 or the developing apparatus 221. The developing sleeve 204 is arranged so as to oppose the photosensitive drum 201 and bears developer. The electrostatic latent image is developed by the developing sleeve 204 and a toner image (developer image) is formed on the circumferential surface of the photosensitive drum 201 (developing step).
A transfer roller 205 that is roller-like transfer means is arranged so as to oppose the photosensitive drum 201. When a recording material P2 conveyed to the transfer roller 205 passes the transfer roller 205 at a predetermined control timing, a transfer bias is applied to the transfer roller 205 and the toner image on the circumferential surface of the photosensitive drum 201 is electrostatically transferred to a surface of the recording material P2 (transferring step). The recording material P2 after the transferring step is conveyed to fixing means that includes a roller-like heating member and a roller-like pressurizing member, and the fixing means performs a heat and pressure fixing process on the toner image on the recording material P2 to fix the image (fixing step). Residue such as untransferred toner that remains on the circumferential surface of the photosensitive drum 201 after the transferring step is removed by a C blade 207 that is cleaning means (cleaning step). Images are formed by repeating the image forming process (charging, exposing, developing, transferring, fixing, and cleaning steps) described above.
<Developer Amount Detecting Portion of Configuration (a) According to Present Embodiment>
The magnetic single component toner T housed in the toner chamber 217 is supplied from the toner chamber 217 to the developing sleeve 204 by the stirring member 212. The supplied toner T is retained on a surface of the developing sleeve 204 by a magnet that is a magnetic body enveloped by the developing sleeve 204. The toner T held on the surface of the developing sleeve 204 comes into contact with a developing blade 218 constituted by an elastic member with a rotation of the developing sleeve 204 in a direction denoted by R22, subjected to triboelectricity impartation and layer thickness restriction by the developing blade 218, and conveyed to a position opposing the photosensitive drum 201.
As developer amount detecting portions, an antenna member 214 (second electrode) and an antenna member 215 (first electrode) which are a pair of electrodes are arranged with an interval therebetween along a container wall surface (bottom surface) of the toner chamber 217 as electrodes for detecting a toner amount. The antenna members 214 and 215 and a gap therebetween are arranged in an order of the antenna member 215, the gap, and the antenna member 214 in a rotating direction of the stirring member 212 which is a direction of movement of the stirring member 212 when a stirring portion is positioned below a stirring shaft (rotary shaft). The stirring portion of the stirring member 212 is configured so that a tip side thereof slides against at least the bottom surface of the toner chamber 217 and also comes into sliding contact with the antenna members 214 and 215 installed on the bottom surface.
In this case, a bottom surface refers to a portion which is a lower wall surface area among areas opposing each other in a vertical direction on a wall surface forming the toner chamber in the frame body of the developer container (an area opposing a ceiling area of the toner chamber) and on which the toner is mounted even if temporarily.
The antenna members 214 and 215 have conductive properties and when the cartridge is mounted to the apparatus main body, the antenna member become electrically conductive with the apparatus main body and are used to detect a developer amount. A contact 2104 (a second terminal) that provides electrical continuity with the antenna member 214 and a contact 2105 (a first terminal) that provides electrical continuity with the antenna member 215 is provided on the apparatus main body 2100. A contact 2106 (a third terminal) that provides electrical continuity with an antenna member 226 of the cartridge B2 (to be described later) is configured as a float. In a state where the cartridge A2 is mounted to the apparatus main body 2100, voltage is input to the antenna member 215 from the apparatus main body 2100 through the contact 2105. The antenna member 214 outputs voltage in accordance with capacitance between the antenna member 214 and the antenna member 215 to the apparatus main body 2100 through the contact 2104. The capacitance is correlated with an amount of developer between the antenna member 214 and the antenna member 215.
In addition, the cartridge B2 according to the present embodiment includes the cleaning apparatus 230 and the developing apparatus 221 in a similar manner to the cartridge A2. The developing sleeve 204 is rotatably arranged in the developing apparatus 221, and the developing apparatus 221 includes toner chambers 227 and 228 housing the toner T and a communication port 220 for supplying toner from the toner chamber 228 (second housing area) to the toner chamber 227 (first housing area). The toner T in the toner chamber 228 is conveyed from the toner chamber 228 to the toner chamber 227 through the communication port 220 by a toner stirrer 223 (second stirring member). The magnetic single component toner T in the toner chamber 227 is conveyed from the toner chamber 227 to the developing sleeve 204 by a toner stirrer 222 (first stirring member).
As a developer amount detecting portion, an antenna member 224 (second electrode), an antenna member 225 (first electrode, third electrode), and an antenna member 226 (fourth electrode) are arranged at intervals along container wall surfaces of the toner chambers 227 and 228. In particular, the antenna member 225 is arranged so as to straddle a container wall surface between the toner chambers 227 and 228. Therefore, a portion of the antenna member 225 arranged in the toner chamber 227 becomes an electrode member (first electrode) used for detection of a toner amount in the toner chamber 227 and a portion of the antenna member 225 arranged in the toner chamber 228 becomes an electrode member (third electrode) used for detection of a toner amount in the toner chamber 228. Due to such a configuration of the antenna member 225, the number of electrode members can be reduced. The antenna members 224 and 225 and a gap therebetween are arranged in an order of the antenna member 225, the gap, and the antenna member 224 in a rotating direction of the toner stirrer 222 which is a direction of movement of the toner stirrer 222 when a stirring portion is positioned below a stirring shaft (rotary shaft). The stirring portion of the toner stirrer 222 is configured so that a tip side thereof slides against at least the bottom surface (first bottom surface) of the toner chamber 227 and also comes into sliding contact with the antenna members 224 and 225 installed on the bottom surface. In addition, the antenna members 224 and 225 and a gap therebetween are arranged in an order of the antenna member 226, the gap, and the antenna member 225 in a rotating direction of the toner stirrer 223 which is a direction of movement of the toner stirrer 223 when a stirring portion is positioned below a stirring shaft (rotary shaft). The stirring portion of the toner stirrer 223 is configured so that a tip side thereof slides against at least the bottom surface (second bottom surface) of the toner chamber 228 and also comes into sliding contact with the antenna members 225 and 225 installed on the bottom surface. The antenna members 224, 225, and 226 have conductive properties and when the cartridge is mounted to the apparatus main body, the antenna members become electrically conductive with the apparatus main body and are used to detect a developer amount. The contact 2104 that provides electrical continuity with the antenna member 224, the contact 2105 that provides electrical continuity with the antenna member 225, and the contact 2106 that provides electrical continuity with the antenna member 226 are provided on the apparatus main body 2100. In a state where the cartridge B2 is mounted to the apparatus main body 2100, voltage is input to the antenna member 225 from the apparatus main body 2100 through the contact 2105. The antenna member 224 outputs voltage in accordance with capacitance between the antenna member 224 and the antenna member 225 to the apparatus main body 2100 through the contact 2104. The capacitance (first capacitance) is correlated with an amount of developer between the antenna member 224 and (a toner chamber 227 side portion of) the antenna member 225. In a similar manner, the antenna member 226 outputs voltage in accordance with capacitance between the antenna member 226 and the antenna member 225 to the apparatus main body 2100 through the contact 2106. The capacitance (second capacitance) is correlated with an amount of developer between the antenna member 226 and (a toner chamber 228 side portion of) the antenna member 225.
As described above the cartridges A2 (
As described above, the apparatus main body 2100 of the image forming apparatus according to the present embodiment is configured such that a plurality of types of cartridges A2 (
A configuration to which the present invention can be applied is not limited to the configuration according to the present embodiment and the present invention can be applied to configurations in which any of the number or shape of the developer amount detecting portion, the number of voltage input, the number of voltage output, and the like or a combination thereof is different. For example, the present invention can even be applied to a configuration in which the developing sleeve 204 functions as an electrode for detecting a developer amount in a housing chamber.
<Cartridge Identifying Member>
As described above, when the cartridges A2 (
A control member (controller) provided on the apparatus main body 2100 of the image forming apparatus is constituted by a microcomputer (control means 255) made up of a memory (storage member) such as a ROM or a RAM and a CPU, various input/output control circuits, and the like.
In this case, information that identifies a cartridge type is respectively stored in storage media 219 and 229 that are microchips or the like provided in the cartridges A2 and B2. The control member of the apparatus main body 2100 provides electrical continuity with the storage medium 219 or the storage medium 229, acquires information related to a developer housing amount stored in the storage medium 219 or the storage medium 229, and distinguishes between the cartridge A2 and the cartridge B2 (distinguishing portion). A distinguished result is stored in a memory and used in a developer amount detection system 250 when calculating a remaining developer amount according to the type of the cartridge.
As described above, in the present embodiment, a type of a cartridge is distinguished based on information related to a developer housing amount stored in a storage medium attached to the cartridge. However, other configurations may be adopted as long as a type of a cartridge can be distinguished at the apparatus main body. Examples include any of a distinguishing method based on a difference in container shapes, a distinguishing method based on a difference in configurations of or numbers of a developer amount detecting portions (for example, a distinguishing method based on a difference in capacitance or whether or not electrical continuity is provided), and the like or a combination of these methods.
<Developer Amount Detection System>
The apparatus main body 2100 determines a type of a mounted cartridge using a cartridge identifying member and, as a result, changes the number of output values, a threshold, and a computing method of the developer amount detecting portion.
<Developer Amount Detecting Method>
In the present embodiment, the cartridge A2 and the cartridge B2 can be mounted to the apparatus main body 2100. Cartridge identifying members are respectively annexed to the cartridges A2 and B2, and when the cartridge A2 or the cartridge B2 is mounted, the apparatus main body 2100 provides electrical continuity with the cartridge identifying members to distinguish between the cartridges A2 and B2. In addition, the cartridge A2 and the cartridge B2 differ from each other in configurations of developer amount detecting portions and when mounted to the apparatus main body 2100, the cartridges A2 and B2 have different circuit configurations as developer amount detection systems as shown in
S701: Mount a cartridge to the apparatus main body.
S702: Determine the type of the cartridge using the cartridge identifying member, and advance to S703 when the cartridge is determined to be the cartridge A2 and advance to S708 when the cartridge is determined to be the cartridge B2.
(When Determined to be Cartridge A2 (First Cartridge))
S703: Measure detection voltage V24 through the detection circuit 253.
S704: Compute and digitally-convert V24 using the A/D conversion member 254 to generate V24A. At this point, a method of computing V24 by the A/D conversion member 254 differs between the cartridges A2 and B2.
S705: Collate a value of V24A with a remaining developer amount table TA (a table including a correspondence relationship between detected voltage values and developer amounts) stored in advance in a memory and convert the value of V24A into a remaining developer amount Y2 [%]. In this case, the remaining developer amount table TA refers to a table for the cartridge A2 which provides V24A with a threshold and associates the remaining developer amount Y2 [%] and V24A with each other so that Y2 [%] is converted in 1% increments. This threshold differs between the cartridge A2 and the cartridge B2.
S706: Display Y2 [%] on the display means 256.
S707: Check whether or not remaining developer amount Y2 [%] has reached 0%. Advance to S703 when a determination of “NO” is made and advance to S713 when a determination of “YES” is made.
(When determined to be cartridge B2 (second cartridge))
S708: Measure detection voltage V24 through the detection circuit 253.
S709: Compute and digitally-convert V24 using the A/D conversion member 254 to generate V24B. At this point, a method of computing V24 by the A/D conversion member 254 differs between the cartridges A2 and B2.
S710: Collate a value of V24B with a remaining developer amount table TB stored in advance in a memory and convert the value of V24B into a remaining developer amount Y2 [%]. In this case, the remaining developer amount table TB refers to a table for the cartridge B2 which provides V24B with a threshold and associates the remaining developer amount Y2 [%] and V24B with each other so that Y2 [%] is converted in 1% increments. This threshold differs between the cartridge A2 and the cartridge B2.
S711: Display Y2 [%] on the display means 256.
S712: Check whether or not remaining developer amount Y2 [%] has reached 0%. Advance to S708 when a determination of “NO” is made and advance to S713 when a determination of “YES” is made.
S713: End developer amount detection.
As described above, while both a computing method and a threshold in a developer amount detecting operation are changed depending on the type of cartridge in the present embodiment, the present invention is not limited thereto and other configurations which change either the computing method or the threshold or a combination thereof may be adopted.
In the third embodiment, in a developer amount detection system, developer amount detection is performed by inputting a voltage V23 that combines a voltage V21 generated at the antenna member 224 and a voltage V21 generated at the antenna member 226 in the cartridge B2 to the detection circuit 253.
A fourth embodiment of the present invention is configured to perform developer amount detection without combining voltages V21 and V22 respectively generated at the antenna members 224 and 225. Specifically, in accordance with a remaining developer amount, any of the voltages V21 and V22 to be input to the detection circuit 253 is selected and used to detect a remaining developer amount.
Hereinafter, descriptions of sections that overlap with the third embodiment will be omitted and feature portions of the fourth embodiment will be mainly described. It is to be understood that matters not described here are similar to those described in the third embodiment.
<Developer Amount Detection System of Configuration (a) According to Present Embodiment>
<Developer Amount Detecting Method>
S1301: Mount a cartridge to the apparatus main body.
S1302: Determine the type of the cartridge using the cartridge identifying member, and advance to S1303 when the cartridge is determined to be the cartridge A2 and advance to S1308 when the cartridge is determined to be the cartridge B2.
(When Determined to be Cartridge A2)
S1303: Measure detection voltage V25 through the detection circuit 253.
S1304: Compute and digitally-convert V25 using the A/D conversion member 254 to generate V25A. At this point, a method of computing V25 by the A/D conversion member 254 differs between the cartridges A2 and B2.
S1305: Collate a value of V25A with a remaining developer amount table TA1 stored in advance in a memory and convert the value of V25A into a remaining developer amount Y2 [%]. In this case, the remaining developer amount table TA1 refers to a table for the cartridge A2 which provides V25A with a threshold and associates the remaining developer amount Y2 [%] and V25A with each other so that Y2 [%] is converted in 1% increments. This threshold differs between the cartridge A2 and the cartridge B2.
S1306: Display Y2 [%] on the display means 256.
S1307: Check whether or not remaining developer amount Y2 [%] has reached 0%. Advance to S1303 when a determination of “NO” is made and advance to S1318 when a determination of “YES” is made.
(When Determined to be Cartridge B2)
S1308: Measure detection voltage V26 through the detection circuit 253.
S1309: Compute and digitally-convert V26 using the A/D conversion member 254 to generate V26B.
S1310: Collate a value of V26B with a remaining developer amount table TB1 (second table) stored in advance in a memory and convert the value of V26B into a remaining developer amount Y2 [%]. In this case, the remaining developer amount table TB1 refers to a table for the cartridge B2 (for detection of a remaining developer amount in the toner chamber 228) which provides V26B with a threshold and associates the remaining developer amount Y2 [%] and V26B with each other so that Y2 [%] is converted in 1% increments. This threshold differs between the cartridge A2 and the cartridge B2.
S1311: Display Y2 [%] on the display means 256.
S1312: Check whether or not the remaining developer amount Y2 [%] has reached a value corresponding to 200 g (whether or not an amount of the developer has equaled or fallen below a predetermined threshold). Advance to S1308 when a determination of “NO” is made and advance to S1313 when a determination of “YES” is made.
S1313: Measure detection voltage V25 through the detection circuit 253.
S1314: Compute and digitally-convert V25 using the A/D conversion member 254 to generate V25B. At this point, a method of computing V25 by the A/D conversion member 254 differs between the cartridges A2 and B2.
S1315: Collate a value of V25B with a remaining developer amount table TB2 (first table) stored in advance in a memory and convert the value of V25B into a remaining developer amount Y2 [%]. In this case, the remaining developer amount table TB2 refers to a table for the cartridge B2 (for detection of a remaining developer amount in the toner chamber 227) which provides V25B with a threshold and associates the remaining developer amount Y2 [%] and V25B with each other so that Y2 [%] is converted in 1% increments. Moreover, the same threshold may be used for the cartridge A2 and the cartridge B2 and the remaining developer amount table TA1 may be used as the remaining developer amount table TB2.
S1316: Display Y2 [%] on the display means 256.
S1317: Check whether or not remaining developer amount Y2 [%] has reached 0%. Advance to S1313 when a determination of “NO” is made and advance to S1318 when a determination of “YES” is made.
S1318: End developer amount detection.
As described above, while both a computing method and a threshold in a developer amount detecting operation are changed depending on the type of cartridge in the present embodiment, the present invention is not limited thereto and other configurations which change either the computing method or the threshold or a combination thereof may be adopted.
The fifth embodiment according to the present invention will now be described.
Developer amount detecting means according to the fifth embodiment will be described with reference to
As shown in
In this case, using an area S of the antenna member 371 (the antenna member 372), a distance d3 between the antenna member 371 and the antenna member 372, and specific dielectric constant K∈, capacitance C3 between the antenna member 371 and the antenna member 372 may be expressed as follows.
C3=K∈×S/d3 (2)
The specific dielectric constant K∈ in Expression (2) changes depending on the developer amount between the antenna member 371 and the antenna member 372. When the developer amount between the antenna member 371 and the antenna member 372 is large, the specific dielectric constant K∈ increases and the capacitance C3 also increases. In addition, when the developer amount between the antenna member 371 and the antenna member 372 is small, the specific dielectric constant K∈ decreases and the capacitance C3 also decreases. Using this relationship, a developer amount in the developer container 311A can be detected based on a change in combined capacitance that combines capacitance between the antenna member 371 and the antenna member 372 and capacitance between the developing roller 302 and the antenna member 371.
Next, a configuration for extending a period of time during which developer is positioned between the antenna member 371 and the antenna member 372 will be described with reference to
In this case, a part of the ceiling surface 311C of the developer container 311A in the housing chamber 311S constitutes the contact portion 313 which is capable of coming into contact with a stirring portion 160b of the rotating stirring member 160. When the stirring member 160 rotates, the stirring portion 160b comes into contact with the contact portion 313 and the contact portion 313 pushes off the developer on the stirring portion 160b so that the developer drops to the bottom surface 311B at a faster rate than when dropping from the stirring portion 160b by its own weight. In other words, the contact portion 313 comes into contact with the stirring member 160 so as to gradually narrow a space on the stirring member 160 on which the developer can be loaded. As shown in
As described earlier, the antenna member 371 and the antenna member 372 are provided on the bottom surface 311B. In the fifth embodiment, the bottom surface 311B constitutes a depressed port ion and the interval D provided between the antenna member 371 and the antenna member 372 is positioned at a lowermost portion of the depressed portion or in a vicinity thereof. Accordingly, the developer having dropped from the stirring portion 160b gathers in the interval D provided between the antenna member 371 and the antenna member 372. Moreover, while apart of the ceiling surface 311C of the developer container 311A constitutes the contact portion 313 in the present embodiment, the contact portion 313 may be provided as a separate member from the ceiling surface 311C. However, the contact portion 313 is not limited to the ceiling surface and may have a shape of a convex portion that protrudes toward a bottom portion. The contact portion is provided for causing developer to efficiently drop to the gap in the bottom portion. A relationship between a length of the contact portion and the interval D is favorably expressed as 2×interval D≦contact portion≦4×interval D and more favorably expressed as 2×interval D≦contact portion≦3×interval D.
Next, a positional relationship among the stirring member 160, the bottom surface 311B, and the contact portion 313 will be described. In
In the present embodiment, a position where contact between the stirring portion 160b of the stirring member 160 and the contact portion 313 starts is above the antenna member 371 and the antenna member 372 in a vertical direction. In addition, as shown in
Next, a relationship between a rotational movement of the stirring member 160 and a detected developer amount will be described. Since the developing apparatus according to the present embodiment is similar to that of the first embodiment,
A change in combined capacitance caused by rotation of the stirring member 160 will be described with reference to
First, at a timing where the stirring portion 160b passes position T11 in
At a timing where the stirring portion 160b passes position T12 in
At a timing where the stirring portion 160b passes position T13 in
At a timing where the stirring portion 160b passes position T14 in
At this point, in the developing apparatus 140 according to the embodiment, as shown in
On the other hand, in the developing apparatus 3111 according to the comparative example, as shown in
At a timing where the stirring portion 160b passes position T15 in
Next, an improvement in detection accuracy of a developer amount by increasing the period of time over which developer is positioned in the interval D between the antenna member 371 and the antenna member 372 in the present embodiment will be described.
As described above, in the fifth embodiment, the contact portion pushes the developer on the stirring member so that the developer drops at a faster rate than when dropping from the stirring member by its own weight. Accordingly, the developer on the stirring member drops to the bottom surface of the housing chamber at a faster rate than when dropping by its own weight. In addition, a detecting portion for detecting an amount of developer is provided on the bottom surface of the housing chamber and, by increasing a period of time in which the developer is loaded on the bottom surface, a developer amount can be accurately detected even when the amount of the developer becomes small.
In addition, in the fifth embodiment, the contact portion comes into contact with the stirring member so as to gradually narrow a space on the stirring member where the developer can be loaded. Accordingly, as described earlier, the period of time in which the developer is loaded on the bottom surface can be increased and a developer amount can be accurately detected even when the amount of the developer becomes small.
Furthermore, in the fifth embodiment, the contact portion comes into contact with the developer on the stirring member at a position above the stirring shaft of the stirring member. Accordingly, the developer on the stirring member drops from above a rotary shaft of the stirring member and the developer in the housing chamber is sufficiently stirred.
In addition, in the fifth embodiment, when a length from a rotational axis of the stirring member to a tip of the stirring member is denoted by A, a vertically downward distance between the rotational axis to the bottom surface of the housing chamber is denoted by B, and a shortest distance between the rotational axis to the contact portion is denoted by C, A≧B and A>C are satisfied. Accordingly, the developer loaded on the bottom surface can be sufficiently stirred and, at the same time, a developer amount can be detected with accuracy even when the amount of the developer is small.
Next, a sixth embodiment of the present invention will be described with reference to
A housing chamber inside the developer container 3211A includes the first housing chamber 3212S and a second housing chamber 3213S. In addition, the first stirring member 3410 is configured by attaching a stirring portion 3412 to a rotary shaft 3411 and rotates around the rotary shaft 3411. The second stirring member 3420 is configured by attaching a stirring portion 3422 to a rotary shaft 3421. Furthermore, the antenna member 373 and the antenna member 374 are used to detect an amount of developer housed in the developer container 3211A. The antenna member 373 is provided on a bottom surface 3212B of the developer container 3211A in the first housing chamber 3212S, and the antenna member 374 is provided on the bottom surface 3212B at an interval from the antenna member 373.
The bottom surface in the developer container 3211A according to the present embodiment is configured to have two depressed portions that are depressed downward in a vertical direction. A space in the developer container 3211A is divided into a space on a near side of the developing roller 302 (the first housing chamber 3212S) and a space on a far side of the developing roller 302 (the second housing chamber 3213S) by a convex portion that protrudes upward in a vertical direction between the two depressed portions on the bottom surface.
The first stirring member 3410 is arranged in the first housing chamber 3212S in the developer container 3211A and stirs toner inside the first housing chamber 3212S so that the toner inside the first housing chamber 3212S is supplied to the developing roller 302. In addition, the second stirring member 3420 is arranged in the second housing chamber 3213S in the developer container 3211A and stirs toner in the second housing chamber 3213S so that the toner in the second housing chamber 3213S moves over the convex portion and into the first housing chamber 3212S.
Furthermore, the antenna member 375 and the antenna member 376 are used to detect an amount of developer housed in the developer container 3211A. The antenna member 375 is provided on a bottom surface 3212B of the developer container 3211A in the second housing chamber 3213S, and the antenna member 376 is provided on the bottom surface 3213B at an interval from the antenna member 375. Moreover, in the sixth embodiment, an amount of developer housed in the developing apparatus 3211 is set to 400 g when the developing apparatus 3211 is not in use. In addition, in the sixth embodiment, the antenna member 373 and the antenna member 374 are provided on the bottom surface 3212B so as to oppose each other, and the antenna member 375 and the antenna member 376 are provided on the bottom surface 3213B so as to oppose each other.
Next, a method of obtaining an amount of developer housed in the housing chamber 3211A based on a change in capacitance between the antenna member 373 and the antenna member 374 and a change in capacitance between the antenna member 375 and the antenna member 376 will be described with reference to
Next, a reason of an improvement of detection accuracy of a developer amount in the developing apparatus according to the sixth embodiment will be described. In the sixth embodiment, a part of a ceiling surface 3213C of the developer container 3211A in the developer container 3211A constitutes a contact portion 3214. In a similar manner to the fifth embodiment, the contact portion 3214 pushes off the developer on the stirring member 3420 so that the developer drops at a faster rate than when dropping from the stirring member 3420 by its own weight.
In
In addition, a length A11 represents a length from a rotational axis of the stirring member 3410 to a tip 3412A of the stirring portion 3412 and a distance B11 represents a distance in a vertical direction between the rotational axis of the stirring member 3410 to the bottom surface 3212B of the housing chamber 3212S. In addition, a distance C11 represents a shortest distance from the rotational axis of the stirring member 3410 to the ceiling surface 3213C. In the stirring member 3410, the length A11 is equal to or longer than the distance B11 and shorter than the distance C11.
In the sixth embodiment, an interval of the antenna member 373 and the antenna member 374 is shorter than an interval of the antenna member 375 and the antenna member 376. Therefore, a change in capacitance between the antenna member 373 and the antenna member 374 is larger than a change in capacitance between the antenna member 375 and the antenna member 376. In the sixth embodiment, in order to suppress a decline in detection accuracy of a developer amount due to the interval of the antenna member 375 and the antenna member 376 being large, a configuration is adopted in which the rotating second stirring member 3420 abuts the contact portion 3214 that is a part of the ceiling surface 3213C. Moreover, the sixth embodiment adopts such a configuration in order to suppress a decline in developer detection accuracy when a developer amount in the developer container 3211A is around 100 to 200 g.
As described above, the sixth embodiment is capable of producing a similar effect to the fifth embodiment. In addition, in the sixth embodiment, developer detection accuracy when a developer amount in the developer container is around 100 to 200 g can be improved as described earlier.
Moreover, while a developer amount in a developer container is detected based on a change in capacitance in the respective embodiments, a method of detecting a developer amount is not limited thereto. For example, a developer amount in a housing chamber may be acquired by irradiating the inside of a developer container with detection light. In this case, the first electrode is replaced with a first light guiding member that guides detection light into the housing chamber and the second electrode is replaced with a second light guiding member that guides the detection light guided into the housing chamber by the first light guiding member to a light receiving member outside of the housing chamber. In addition, an amount of developer housed in the housing chamber is acquired by measuring a time at which the detection light reaches the light receiving member.
Alternatively, a developer amount in the developer container may be obtained by measuring duty of a capacitance profile while the stirring member makes one round. In this case, a determination that a toner amount in the developer container is large is made when the period of time at which capacitance is on a + signal side is long while the stirring member makes one round. Since the period of time at which combined capacitance exceeds a threshold differs depending on a toner amount in the developer container, a toner amount can be obtained by measuring the period of time at which combined capacitance exceeds a threshold.
<Initial Capacitance Detecting Method>
In the configuration described so far, due to a stirring operation of developer, a state where developer in an area of the gap X1 (
Specifically, tapping occurs during transportation of a developer container, a developing apparatus, a process cartridge, or an image forming apparatus when vibration due to distribution coincides with long-term standing to cause air inside the developer escape s significantly prior to installation by a user.
When the user performs image formation in this state as shown in
Consequently, a difference between a highest capacitance value (a capacitance value influenced by tapping) obtained in a detection area in an initial stage of a durability test and capacitance detected at a predetermined durability test timing ends up being detected. Accordingly, when calculating a developer amount based on the detected value and a threshold of a remaining amount %, an abnormally large capacitance value is detected.
In addition, since a greater-than-expected difference is created when detecting a remaining amount in a later stage of a durability test, a notification is made that the remaining developer amount is smaller than normal or, in other words, that the remaining amount is decreasing at a faster rate.
In consideration thereof, in the present embodiment, as shown in
Unlike the capacitance value when subjected to tapping, the capacitance value at this point is a highest value among normal initial values of capacitance in a state of normal use by the user after installation of the main body (state immediately after the start of use of the image forming apparatus). The present embodiment adopts a configuration in which this value is detected as a representative value for calculating a remaining toner amount. In other words, the effect of vibration during distribution is not resolved unless a T stirring operation is performed. Therefore, by monitoring an initial change in capacitance and calculating a remaining toner amount by comparing a capacitance value having temporarily decreased and subsequently increased as a representative value with a capacitance value at a predetermined timing, a remaining toner amount can be detected on toner freed from tapping.
Moreover, since a state freed from tapping as described above occurs after the main body is installed and is no longer affected by distribution, when the amount of toner in the detection area is largest even during a durability test, a normal capacitance value as though obtained during normal use can be detected.
In consideration thereof, as a specific control method according to the present embodiment, detection of capacitance is started at the gap X1 from an initial stage and a decline in the capacitance value as passage of paper advances is monitored. Subsequently, remaining amount detection can be performed more accurately by determining a representative value of the capacitance value when capacitance increases, detecting a difference between the representative value and capacitance detected at a predetermined durability test timing, and calculating a developer amount based on the detected value and a threshold of remaining amount %.
The seventh embodiment and a comparative example 2 that is a conventional configuration will now be compared and described with reference to Table 1. Comparative example 2 is a conventional configuration in which an electrode member is provided in a stirred container. Since the state of developer does not stabilize (toner in a capacitance detection area is affected by stirring) in this configuration, it is difficult to detect a developer amount with high accuracy. However, with the present configuration, by providing the gap X1 using a plurality of electrodes on a bottom portion of a stirred area, a change in capacitance when a toner amount is small can be increased, and an advantage is gained in that accuracy of developer amount detection can be improved when the toner amount is small.
In addition, regarding the effect of tapping, since comparative example 2 is less likely to detect a degree of mixing of developer and air due to stirring, it is difficult to accurately detect a developer amount. In contrast, in the present embodiment, electrodes are provided below stirring where a change in capacitance becomes prominent and states where air is included and air is not included due to the developer's own weight can be determined more accurately and in a shorter amount of time. Furthermore, since a point where capacitance increases after a capacitance value declines in an initial state of a durability test is detected as a representative value of the capacitance value, an accuracy of remaining amount detection can be improved regardless of a durability test timing.
Moreover, while vertical axes in
According to the present invention, a developer container, a developing apparatus, a process cartridge, and an image forming apparatus which enable a developer amount to be detected at high accuracy can be provided.
The present eighth embodiment differs from the seventh embodiment in the method of calculating a representative value of initially detected capacitance. Hereinafter, differences from the seventh embodiment will be described and matters that are similar to those of the seventh embodiment will not be described.
The present embodiment differs from the seventh present embodiment in the method of calculating a maximum value of capacitance values. Hereinafter, differences from the seventh embodiment will be described and matters that are similar to those of the seventh embodiment will not be described.
Moreover, in the embodiment described above, the contact portion 313 according to the fifth embodiment can be provided in the toner chamber 147 according to the first embodiment. In addition, in the embodiment described above, the method of acquiring a toner amount according to the seventh to ninth embodiments can be adopted for the toner chamber 147 according to the first embodiment. Furthermore, in other embodiments, configurations of the respective embodiments can also be combined with configurations of other embodiments.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2015-017025, filed on Jan. 30, 2015, Japanese Patent Application No. 2015-017226, filed on Jan. 30, 2015, Japanese Patent Application No. 2015-016253, filed on Jan. 30, 2015 and Japanese Patent Application No. 2015-243270, filed on Dec. 14, 2015, which are hereby incorporated by reference herein in its entirety.
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