Patent Description:
Typically, an image forming apparatus of an electrophotographic system forms an image by transferring a toner image formed on the surface of a photosensitive drum onto a transfer material serving as a transfer medium. In addition, as a replenishment system of developer, for example, a process cartridge system and a toner replenishment system are known. The process cartridge system is a system in which a photosensitive drum and a developer container are integrated as a process cartridge and the process cartridge is replaced by a new one when the developer is run out.

In contrast, the toner replenishment system is a system in which the developer container is replenished with new toner when the toner is run out. Conventionally, a one-component developing apparatus of a toner replenishment system in which a toner supply box capable of replenishing toner is connected to a toner conveyance path in which toner is conveyed is proposed (see <CIT>). Toner reserved in the toner supply box is conveyed to the toner conveyance path by a conveyance screw.

<CIT> shows a generic image forming apparatus according to the preamble of claim <NUM>, to and from which a replenishment container accommodating developer is attachable and detachable and which is configured to execute an image formation in which a developer image is formed on a recording material, the image forming apparatus comprising: an image bearing member configured to rotate while bearing the developer image; a developer bearing member configured to bear the developer and supply the developer to the image bearing member; a developer container including: an accommodating portion configured to accommodate the developer to be borne on the developer bearing member, and a replenishment port to and from which the replenishment container is attachable and detachable and through which the accommodating portion is replenished with the developer from the replenishment container; an agitation member configured to agitate the developer accommodated in the accommodating portion; an opening/closing member configured to be movable between a closed position where the opening/closing member closes the replenishment port such that the replenishment container is not attachable to the developer container, and an open position where the opening/closing member opens the replenishment port such that the replenishment container is attachable to the developer container; an opening/closing sensor configured to detect whether the opening/closing member is at the open position or at the closed position; and a control means configured to control driving of the agitation member.

Further image forming apparatuses according to the prior art are shown in <CIT> and <CIT>.

In recent years, for an image forming apparatus, users have desired various systems such as the process cartridge system and the toner replenishment system described above.

It is the object of the present invention to further develop an image forming apparatus according to the preamble of claim <NUM> such that an improved usability/operability of the image forming apparatus during and after a developer replenishment process can be provided.

The object of the present invention is achieved by an image forming apparatus having the features of claim <NUM>.

According to the present invention, a mode of an image forming apparatus can be provided.

The above and other features, effects and advantages of the present invention will be revealed by the following description with reference to attached drawings. To be noted, in the attached drawings, the same or similar elements are denoted by the same reference numerals.

Exemplary embodiments of the present invention will be described below with reference to drawings.

<FIG> is a schematic diagram illustrating a configuration of an image forming apparatus <NUM> according to a first embodiment. The image forming apparatus <NUM> is a monochromatic printer that forms an image on a recording material on the basis of image information input from an external device. Examples of the recording material include various sheet materials of different materials like paper sheets such as plain paper sheets and cardboards, plastic films such as sheets for overhead projectors, sheets of irregular shapes such as envelops and index paper sheets, and cloths.

As illustrated in <FIG>, the image forming apparatus <NUM> includes a printer body <NUM> serving as an apparatus body, a reading apparatus <NUM> openably and closably supported by the printer body <NUM>, and an operation portion <NUM> attached to an exterior surface of the printer body <NUM>. The printer body <NUM> includes an image forming portion <NUM> that forms a toner image on a recording material, a feeding portion <NUM> that feeds the recording material to the image forming portion <NUM>, a fixing portion <NUM> that fixes the toner image formed by the image forming portion <NUM> to the recording material, and a discharge roller pair <NUM>.

The image forming portion <NUM> includes a scanner unit <NUM>, a process cartridge <NUM> of an electrophotographic system, and a transfer roller <NUM> that transfers a toner image serving as a developer image formed on a photosensitive drum <NUM> of the process cartridge <NUM> onto the recording material. As illustrated in <FIG>, the process cartridge <NUM> includes the photosensitive drum <NUM>, a charging roller <NUM> disposed in the vicinity of the photosensitive drum <NUM>, and a developing apparatus <NUM> including a pre-exposing apparatus <NUM> and a developing roller <NUM>.

The photosensitive drum <NUM> is a photoconductor formed in a cylindrical shape. The photosensitive drum <NUM> of the present embodiment includes a drum-shaped base body formed from aluminum, and a photosensitive layer formed from a negatively-chargeable organic photoconductor thereon. In addition, the photosensitive drum <NUM> serving as an image bearing member is rotationally driven by a motor in a predetermined direction (clockwise direction in the figure) at a predetermined process speed.

The charging roller <NUM> comes into contact with the photosensitive drum <NUM> at a predetermined pressure contact force to form a charging portion. In addition, a desired charging voltage is applied thereto by a charging high-voltage power source, and thus the surface of the photosensitive drum <NUM> is uniformly charged to a predetermined potential. In the present embodiment, the photosensitive drum <NUM> is charged to a negative polarity by the charging roller <NUM>. The pre-exposing apparatus <NUM> de-electrify the surface potential of the photosensitive drum <NUM> before entering the charging portion so as to cause stable electrical discharge in the charging portion.

The scanner unit <NUM> serving as an exposing means exposes the surface of the photosensitive drum <NUM> in a scanning manner by radiating laser light corresponding to the image information input from the external device or the reading apparatus <NUM> onto the photosensitive drum <NUM> by using a polygon mirror. As a result of this exposure, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum <NUM>. To be noted, the scanner unit <NUM> is not limited to a laser scanner apparatus, and for example, an LED exposing apparatus including an LED array in which a plurality of LEDs are arranged in the longitudinal direction of the photosensitive drum <NUM> may be employed.

The developing apparatus <NUM> includes a developing roller <NUM> serving as a developer bearing member that bears developer, a developer container <NUM> serving as a frame member of the developing apparatus <NUM>, and a supply roller <NUM> that supplies developer to the developing roller <NUM>. The developing roller <NUM> and the supply roller <NUM> are rotatably supported by the developer container <NUM>. In addition, the developing roller <NUM> is disposed at an opening portion of the developer container <NUM> so as to oppose the photosensitive drum <NUM>. The supply roller <NUM> is rotatably in contact with the developing roller <NUM>, and toner serving as developer accommodated in the developer container <NUM> is applied on the surface of the developing roller <NUM> by the supply roller <NUM>. To be noted, the supply roller <NUM> is not necessary if a configuration in which enough toner can be supplied to the developing roller <NUM> is employed.

For the developing apparatus <NUM> of the present embodiment, a contact developing system is used as the development system. That is, a toner layer borne on the developing roller <NUM> comes into contact with the photosensitive drum <NUM> in a developing portion (developing region) where the photosensitive drum <NUM> and the developing roller <NUM> oppose each other. A developing voltage is applied to the developing roller <NUM> by a developing high-voltage power source. Under the developing voltage, toner borne on the developing roller <NUM> transfers from the developing roller <NUM> onto the drum surface in accordance with the potential distribution of the surface of the photosensitive drum <NUM>, and thus the electrostatic latent image is developed as a toner image. To be noted, in the present embodiment, a reverse development system is employed. That is, toner attaches to a surface region of the photosensitive drum <NUM>. which is charged in a charging step, exposed in an exposing step, and thus has a reduced charge amount, and thus a toner image is formed.

In addition, in the present embodiment, toner having a particle diameter of <NUM> and a normal charging polarity of a negative polarity is used. For example, as the toner of the present embodiment, polymer toner produced by a polymerization method is employed. In addition, the toner of the present embodiment is so-called nonmagnetic one-component developer that does not contain a magnetic component, and is borne on the developing roller <NUM> mainly by intermolecular force or electrostatic force (image force). However, one-component developer containing a magnetic component may be used. In addition, in some cases, the one-component developer contains additives (for example, wax and silica fine particles) for adjusting the fluidity and charging performance of toner in addition to toner particles. In addition, two-component developer constituted by nonmagnetic toner and magnetic carrier may be used as the developer. In the case of using magnetic developer, for example, a cylindrical developing sleeve on the inner circumferential surface of which a magnet is disposed is used as the developer bearing member.

An agitation member <NUM> serving as an agitation means is provided inside the developer container <NUM>. The agitation member <NUM> is driven to pivot by a motor M1 (see <FIG>), thus agitates the toner in the developer container <NUM>, and delivers (conveys) the toner to the developing roller <NUM> and the supply roller <NUM>. In addition, the agitation member <NUM> has a function of circulating toner not used for development and peeled off from the developing roller <NUM> in the developer container to uniformize toner in the developer container. To be noted, the agitation member <NUM> is not limited to a pivoting type. For example, an agitation member of a swinging type may be employed. In addition, another agitation member may be further provided in addition to the agitation member <NUM>.

In addition, a developing blade <NUM> that regulates the amount of toner borne on the developing roller <NUM> is disposed at the opening portion of the developer container <NUM> where the developing roller <NUM> is disposed. The toner supplied to the surface of the developing roller <NUM> passes through the opposing portion between the developing roller <NUM> and the developing blade <NUM> in accordance with the rotation of the developing roller <NUM>, thus forms a uniform thin layer, and is negatively charged by frictional electrification.

As illustrated in <FIG>, the feeding portion <NUM> includes a front door <NUM> openably and closably supported by the printer body <NUM>, a tray portion <NUM>, an inner plate <NUM>, a tray spring <NUM>, and a pickup roller <NUM>. The tray portion <NUM> constitutes a bottom surface of a recording material accommodation space that is exposed by opening the front door <NUM>, and the inner plate <NUM> is supported by the tray portion <NUM> so as to be capable of ascending and descending. The tray spring <NUM> urges the inner plate <NUM> upward, and presses a recording material P supported by the inner plate <NUM> against the pickup roller <NUM>. To be noted, the front door <NUM> closes the recording material accommodation space in the state of being closed with respect to the printer body <NUM>, and supports the recording material P together with the tray portion <NUM> and the inner plate <NUM> in the state of being open with respect to the printer body <NUM>.

The fixing portion <NUM> is of a thermal fixation system that performs an image fixing process by heating and melting toner on a recording material. The fixing portion <NUM> includes a fixing film <NUM>, a fixing heater such as a ceramic heater that heats the fixing film <NUM>, a thermistor that measures the temperature of the fixing heater, and a pressurizing roller <NUM> that is in pressure contact with the fixing film <NUM>.

Next, an image forming operation of the image forming apparatus <NUM> will be described. When a command of image formation is input to the image forming apparatus <NUM>, an image forming process by the image forming portion <NUM> is started on the basis of image information input from an external computer connected to the image forming apparatus <NUM> or from the reading apparatus <NUM>. The scanner unit <NUM> radiates laser light toward the photosensitive drum <NUM> on the basis of the input image information. At this time, the photosensitive drum <NUM> has been already charged by the charging roller <NUM>, and an electrostatic latent image is formed on the photosensitive drum <NUM> as a result of the laser light irradiation. Then, this electrostatic latent image is developed by the developing roller <NUM>, and thus a toner image is formed on the photosensitive drum <NUM>.

In parallel with the image forming process described above, the pickup roller <NUM> of the feeding portion <NUM> delivers out the recording material P supported by the front door <NUM>, the tray portion <NUM>, and the inner plate <NUM>. The recording material P is fed to a registration roller pair <NUM> by the pickup roller <NUM>, and the skew thereof is corrected by abutting a nip of the registration roller pair <NUM>. Then, the registration roller pair <NUM> is driven to match a transfer timing of the toner image, and conveys the recording material P to a transfer nip formed by the transfer roller <NUM> and the photosensitive drum <NUM>.

A transfer voltage is applied to the transfer roller <NUM> serving as a transfer means from a transfer high-voltage power source, and the toner image borne on the photosensitive drum <NUM> is transferred onto the recording material P conveyed by the registration roller pair <NUM>. The recording material P onto which the toner image has been transferred is conveyed to the fixing portion <NUM>, and the toner image is heated and pressurized when passing through a nip portion between the fixing film <NUM> and the pressurizing roller <NUM> of the fixing portion <NUM>. As a result of this, toner particles melt and then adhere, and thus the toner image is fixed to the recording material P. The recording material P having passed through the fixing portion <NUM> is discharged to the outside of the image forming apparatus <NUM> (outside of the apparatus) by the discharge roller pair <NUM> serving as a discharge means, and is supported on a discharge tray <NUM> serving as a supporting portion formed in an upper portion of the printer body <NUM>.

The discharge tray <NUM> is inclined upward toward the downstream side in a discharge direction of the recording material, the recording material discharged onto the discharge tray <NUM> slides down the discharge tray <NUM>, and thus the trailing end thereof is aligned by a regulating surface <NUM>.

As illustrated in <FIG>, the reading apparatus <NUM> includes a reading unit <NUM> including an unillustrated reading portion therein, and a pressure plate <NUM> openably and closably supported by the reading unit <NUM>. A platen glass <NUM> which transmits light emitted from the reading portion and on which a document is to be placed is provided on the upper surface of the reading unit <NUM>.

In the case where an image of a document is to be read by the reading apparatus <NUM>, a user places the document on the platen glass <NUM> in a state in which the pressure plate <NUM> is open. Then, the pressure plate <NUM> is closed to prevent displacement of the document on the platen glass <NUM>, and for example, the operation portion <NUM> is operated to output a reading command to the image forming apparatus <NUM>. When a reading operation is started, the reading portion in the reading unit <NUM> reciprocates in a sub-scanning direction, that is, a left-right direction as viewed from the front of the operation portion <NUM> of the image forming apparatus <NUM>. The reading portion receives light reflected on the document by a light receiving portion while emitting light to the document from a light emitting portion, and performs photoelectric conversion to read the image of the document. To be noted, a front-rear direction, a left-right direction, and an up-down direction are defined on the basis of a state as viewed from the front of the operation portion <NUM>.

As illustrated in <FIG> and <FIG>, a first opening portion <NUM> opening upward is defined in an upper portion of the printer body <NUM>, and the first opening portion <NUM> is covered by a top cover <NUM>. The top cover <NUM> serving as a supporting tray is supported so as to be openable and closable about a pivot shaft 82c extending in the left-right direction with respect to the printer body <NUM>, and the discharge tray <NUM> serving as a supporting surface is formed on the upper surface thereof. The top cover <NUM> is opened from the front side to the rear side in a state in which the reading apparatus <NUM> is open with respect to the printer body <NUM>. To be noted, the reading apparatus <NUM> and the top cover <NUM> may be configured to be held in an open state and a closed state by a holding mechanism such as a hinge mechanism.

For example, in the case where a jam of the recording material occurs due to paper jam or the like in a conveyance path CP which the recording material fed by the pickup roller <NUM> passes through, the user opens the top cover <NUM> together with the reading apparatus <NUM>. Then, the user accesses the process cartridge <NUM> through the first opening portion <NUM> exposed by opening the top cover <NUM>, and draws out the process cartridge <NUM> along cartridge guides <NUM>. The cartridge guides <NUM> slide on and guide projection portions 21a (see <FIG>) provided at end portions of the photosensitive drum <NUM> of the process cartridge <NUM> in the axial direction.

Then, as a result of drawing out the process cartridge <NUM> to the outside through the first opening portion <NUM>, a space through which a hand can access the conveyance path CP is generated. The user can put their hand in the printer body <NUM> through the first opening portion <NUM>, and thus can access the recording material jamming the conveyance path CP to remove the jammed recording material.

In addition, in the present embodiment, as illustrated in <FIG> and <FIG>, an opening/closing member <NUM> is openably and closably provided on the top cover <NUM>. A second opening portion 82a serving as an opening portion opening upward is defined in the discharge tray <NUM> of the top cover <NUM>. The opening/closing member <NUM> is configured to be movable between a closed position where the opening/closing member <NUM> covers the replenishment port 32a such that the toner pack <NUM> cannot be attached to the developer container <NUM>, and an open position where the opening/closing member <NUM> exposes the replenishment port 32a such that the toner pack <NUM> can be attached to the developer container <NUM>. The opening/closing member <NUM> functions as a part of the discharge tray <NUM> in the closed position. The opening/closing member <NUM> and the second opening portion 82a are formed on the left side of the discharge tray <NUM>. In addition, the opening/closing member <NUM> is supported by the top cover <NUM> so as to be openable and closable about a pivot shaft 83a extending in the front-rear direction, and is opened to the left by hooking a finger thereon through a groove portion 82b provided on the top cover <NUM>. The opening/closing member <NUM> is formed in an approximate L shape in accordance with the shape of the top cover <NUM>.

The second opening portion 82a of the discharge tray <NUM> is open such that the replenishment port 32a for toner replenishment defined in an upper portion of the developer container <NUM> is exposed, and the user can access the replenishment port 32a by opening the opening/closing member <NUM> without opening the top cover <NUM>. To be noted, in the present embodiment, a system (direct replenishment system) in which the user replenishes the developing apparatus <NUM> with toner from the toner pack <NUM> (see <FIG>) filled with toner for replenishment in a state in which the developing apparatus <NUM> is still attached to the image forming apparatus <NUM> is employed. Therefore, in the case where the toner remainder amount of the process cartridge <NUM> is small, an operation of taking out the process cartridge <NUM> from the printer body <NUM> and replacing the process cartridge <NUM> with a brand-new process cartridge is no longer necessary, and thus the usability can be improved. In addition, the developer container <NUM> can be replenished with toner at lower cost than replacing the whole process cartridge <NUM>. To be noted, the direct replenishment system can reduce the cost also as compared with the case where only the developing apparatus <NUM> of the process cartridge <NUM> is replaced because there is no need to replace various rollers and gears. To be noted, the image forming apparatus <NUM> and the toner pack <NUM> constitute an image forming system.

In the present embodiment, a cleanerless configuration in which transfer residual toner remaining on the photosensitive drum <NUM> without being transferred onto the recording material P is collected into the developing apparatus <NUM> and reused is employed. The transfer residual toner is removed by the following process. The transfer residual toner includes, in mixture, toner charged to a positive polarity and toner that is charged to a negative polarity but does not have enough charges. The photosensitive drum <NUM> after transfer is de-electrified by the pre-exposing apparatus <NUM>, the charging roller <NUM> is caused to generate uniform electrical discharge, and thus the transfer residual toner is charged to a negative polarity again. The transfer residual toner charged to a negative polarity again in the charging portion reaches the developing portion in accordance with the rotation of the photosensitive drum <NUM>. Then, the surface region of the photosensitive drum <NUM> having passed the charging portion is exposed by the scanner unit <NUM> in a state in which the transfer residual toner is still attached to the surface thereof, and thus an electrostatic latent image is drawn thereon.

Here, the behavior of the transfer residual toner having reached the developing portion will be described separately for an exposed portion and a non-exposed portion of the photosensitive drum <NUM>. In the developing portion, the transfer residual toner attached to the non-exposed portion of the photosensitive drum <NUM> is transferred onto the developing roller <NUM> due to a potential difference between the potential (dark potential) of the non-exposed portion of the photosensitive drum <NUM> and the developing voltage, and is collected into the developer container <NUM>. This is because the developing voltage applied to the developing roller <NUM> is relatively positively polarized with respect to the potential of the non-exposed portion on the premise that the normal charging polarity of the toner is a negative polarity. To be noted, the toner collected into the developer container <NUM> is dispersed by being agitated by the agitation member <NUM> with toner in the developer container, and is borne on the developing roller <NUM> to be used in a developing process again.

In contrast, transfer residual toner attached to the exposed portion of the photosensitive drum <NUM> remains on the drum surface without being transferred from the photosensitive drum <NUM> to the developing roller <NUM> in the developing portion. This is because the potential of the developing voltage applied to the developing roller <NUM> is further on the negative polarity side than the potential (light potential) of the exposed portion on the premise that the normal charging polarity of toner is a negative polarity. The transfer residual toner remaining on the drum surface moves to the transfer portion while being borne on the photosensitive drum <NUM> together with other toner to be transferred from the developing roller <NUM> to the exposed portion, and is transferred onto the recording material P in the transfer portion.

Although a cleanerless configuration in which transfer residual toner is collected into the developing apparatus <NUM> and reused is employed in the present embodiment as described above, a conventionally known configuration in which transfer residual toner is collected by a cleaning blade that abuts the photosensitive drum <NUM> may be employed. In this case, the transfer residual toner collected by the cleaning blade is collected into a collection container provided separately from the developing apparatus <NUM>. However, employing the cleanerless configuration eliminates the necessity to install a collection container for collecting transfer residual toner and the like and thus enables further miniaturization of the image forming apparatus <NUM>, and reuse of transfer residual toner can reduce the printing cost.

Next, the configuration of the developer container <NUM> and the toner pack <NUM> will be described. <FIG> is a perspective view of the developer container <NUM> and the toner pack <NUM>, and <FIG> is a front view of the developer container <NUM> and the toner pack <NUM>. <FIG> is a section view taken along 6A-6A of <FIG>, and <FIG> is a section view taken along 6B-6B of <FIG>.

As illustrated in <FIG>, the developer container <NUM> includes a conveyance chamber <NUM> that accommodates the agitation member <NUM>, and the conveyance chamber <NUM> serving as an accommodation chamber that accommodates toner extends over the entirety of the developer container <NUM> in the longitudinal direction (left-right direction). In addition, the conveyance chamber <NUM> is integrally formed with a frame member rotatably supporting the developing roller <NUM> and the supply roller <NUM>, and accommodates developer to be borne on the developing roller <NUM>. In addition, the developer container <NUM> includes a first projection portion <NUM> serving as a projection portion that projects upward from one end portion of the conveyance chamber <NUM> in the longitudinal direction and communicates with the conveyance chamber <NUM>, and a second projection portion <NUM> that projects upward from the other end portion of the conveyance chamber <NUM> in the longitudinal direction. That is, the first projection portion <NUM> is provided at one end portion of the developer container <NUM> in the rotation axis direction of the developing roller <NUM>, and projects toward the discharge tray <NUM> in a crossing direction crossing the rotation axis direction described above more than the center portion of the developer container <NUM>. The second projection portion <NUM> is provided at the other end portion of the developer container <NUM> in the rotation axis direction of the developing roller <NUM>, and projects toward the discharge tray <NUM> in the crossing direction more than the center portion of the developer container <NUM>. In the present embodiment, the first projection portion <NUM> is formed on the left side of the developer container <NUM>, and the second projection portion <NUM> is formed on the right side of the developer container <NUM>. An attachment portion <NUM> to which the toner pack <NUM> can be attached is provided at an upper end portion (distal end portion) of the first projection portion <NUM>, and a replenishment port 32a for replenishing the conveyance chamber <NUM> with toner from the toner pack <NUM> is defined in the attachment portion <NUM>. The toner pack <NUM> can be attached to the attachment portion <NUM> in the state of being exposed to the outside of the apparatus.

The developer container <NUM> is configured such that toner supplied through the replenishment port 32a reaches the agitation member <NUM> by only its own weight. Here, "its own weight" means that it is configured that the toner reaches the agitation member <NUM> by its own weight even though an agitation member (conveyance member) that rotates or swings for conveying toner is not provided between the replenishment port 32a of the developer container <NUM> and the agitation member <NUM>. In addition, in the developer container <NUM>, the agitation member <NUM> is disposed such that the agitation member <NUM> is the rotary member closest to the replenishment port 32a and the rotation thereof causes the toner in the conveyance chamber <NUM> to reach the developing roller <NUM> or the supply roller <NUM>.

The first projection portion <NUM> and the second projection portion <NUM> extend obliquely upward from the conveyance chamber <NUM> from the front side of the apparatus. That is, the first projection portion <NUM> and the second projection portion <NUM> project downstream and upward in the discharge direction of the discharge roller pair <NUM>. Therefore, the replenishment port 32a formed in the first projection portion <NUM> is disposed on the front side of the image forming apparatus <NUM>, and thus toner replenishment operation for the developer container <NUM> can be performed easily.

Particularly, in the present embodiment, since the reading apparatus <NUM> openable and closable about the rear side of the apparatus is disposed above the opening/closing member <NUM>, the space between the replenishment port 32a and the reading apparatus <NUM> can be used more efficiently by disposing the replenishment port 32a on the front side of the apparatus. Therefore, the operability for replenishing toner from the replenishment port 32a can be improved.

The upper portion of the first projection portion <NUM> and the upper portion of the second projection portion <NUM> are connected to each other by a grip portion <NUM> serving as a connection portion. A laser passage space SP through which laser light L (see <FIG>) emitted from the scanner unit <NUM> (see <FIG>) toward the photosensitive drum <NUM> passes is defined between the grip portion <NUM> and the conveyance chamber <NUM>.

The grip portion <NUM> includes a pinching portion 39a that the user can grip by hooking a finger thereon, and the pinching portion 39a is formed to project upward from the top plate of the grip portion <NUM>. The first projection portion <NUM> is formed to has a hollow shape, and the replenishment port 32a is defined in the upper surface thereof. The replenishment port 32a is configured to be connectable to the toner pack <NUM>.

By providing the first projection portion <NUM>, on a distal end portion of which the replenishment port 32a is defined, on one side of the developer container <NUM> in the longitudinal direction, the laser passage space SP that the laser light L emitted from the scanner unit <NUM> can pass through can be secured, and the image forming apparatus <NUM> can be miniaturized. In addition, since the second projection portion <NUM> is provided on the other side of the developer container <NUM> in the longitudinal direction, and the grip portion <NUM> that connects the first projection portion <NUM> and the second projection portion <NUM> to each other is formed, the usability for taking out the process cartridge <NUM> from the printer body <NUM> can be improved. To be noted, the second projection portion <NUM> may be formed in a hollow shape similarly to the first projection portion <NUM>, or may be formed in a solid shape.

<FIG> is a perspective view of a developer container <NUM> according to a modification example of the first embodiment. The developer container <NUM> includes a projection portion <NUM> disposed at an end portion in the longitudinal direction, and the projection portion <NUM> projects higher than a center portion of the developer container <NUM> in the longitudinal direction. An attachment portion <NUM> for attaching the toner pack <NUM> is provided on the projection portion <NUM>, and a replenishment port 320a is provided in the attachment portion <NUM>.

The projection portion <NUM> is different from the first projection portion <NUM> illustrated in <FIG> in that a recess portion 370a is provided thereon. The recess portion 370a is provided on a side surface of the projection portion <NUM>, and is recessed in a direction from the center portion to an end portion of the developer container <NUM> in the longitudinal direction. Further, the recess amount of the recess portion 370a is larger at a position closer to the photosensitive drum <NUM>. Here, it can be considered that in the case where the distance between the scanner unit <NUM> and the developer container <NUM> is increased, the irradiation region of the laser light L overlaps with the attachment portion <NUM> (replenishment port 320a) as viewed in the attachment direction of the toner pack <NUM>. By providing the attachment portion <NUM> above the laser light L in the vertical direction such that the laser light L passes through the recess portion 370a, interference between the laser light L and the developer container <NUM> can be avoided. As a result of this, it is not necessary to move the projection portion <NUM> further toward the end portion in the longitudinal direction to avoid the interference with the laser light L, and thus the miniaturization of the apparatus can be realized.

As illustrated in <FIG>, the toner pack <NUM> is configured to be attachable to and detachable from the attachment portion <NUM> of the first projection portion <NUM>. In addition, the toner pack <NUM> includes a shutter member <NUM> provided at an opening portion and openable and closable, and a plurality of (in the present embodiment, three) protrusions <NUM> formed in correspondence with a plurality of (in the present embodiment, three) groove portions 32b defined in the attachment portion <NUM>. In the case where the user replenishes the developer container <NUM> with toner, the user positions the toner pack <NUM> such that the protrusions <NUM> pass through the groove portions 32b of the attachment portion <NUM>, and thus connects the toner pack <NUM> to the attachment portion <NUM>. Further, when the toner pack <NUM> is rotated by <NUM>° in this state, the shutter member <NUM> of the toner pack <NUM> abuts an unillustrated abutting portion of the attachment portion <NUM> to rotate with respect to the body of the toner pack <NUM>, and thus the shutter member <NUM> is opened. As a result of this, toner accommodated in the toner pack <NUM> drops from the toner pack <NUM>, and the dropped toner enters the first projection portion <NUM> having a hollow shape through the replenishment port 32a. To be noted, the shutter member <NUM> may be provided on the replenishment port 32a.

The first projection portion <NUM> includes an inclined surface 37a at a position opposing to the opening of the replenishment port 32a, and the inclined surface 37a is inclined downward toward the conveyance chamber <NUM>. Therefore, the toner supplied through the replenishment port 32a is guided to the conveyance chamber <NUM> by the inclined surface 37a. <FIG> is a perspective view of the agitation member <NUM>. As illustrated in <FIG> and <FIG>, the agitation member <NUM> includes an agitation shaft 34a extending in the longitudinal direction, and a blade portion 34b fixed to the agitation shaft 34a and extends radially outward from the agitation shaft 34a. The blade portion 34b is a sheet having flexibility. The agitation member <NUM> rotates about a shaft portion 34c of the agitation shaft 34a.

The toner replenished through the replenishment port 32a disposed upstream of the agitation member <NUM> in the conveyance direction is delivered to the developing roller <NUM> and the supply roller <NUM> in accordance with the rotation of the agitation member <NUM>. The conveyance direction of the agitation member <NUM> is parallel to the longitudinal direction of the developer container <NUM>. Although the replenishment port 32a and the first projection portion <NUM> are disposed at one end portion of the developer container <NUM> in the longitudinal direction, the toner spreads to the whole developer container <NUM> by repetitive rotation of the agitation member <NUM>. To be noted, although the agitation member <NUM> is constituted by the agitation shaft 34a and the blade portion 34b in the present embodiment, an agitation shaft of a spiral shape may be used as an element for spreading the toner to the whole developer container <NUM>.

Although the toner pack <NUM> is constituted by an easily deformable plastic bag as illustrated in <FIG> and <FIG> in the present embodiment, this is not limiting. For example, the toner pack may be constituted by a bottle container 40b having an approximately cone shape as illustrated in <FIG>, or may be formed from a paper container 40C formed from paper as illustrated in <FIG>. In either case, the material and shape of the toner pack may be of any kind. In addition, as a method for discharging toner from the toner pack, it is preferable that the user squeeze the toner pack in the case of the toner pack <NUM> or the paper container 40C, and it is preferable that the user causes the toner to drop while vibrating the container by hitting the container or the like in the case of the bottle container 40B. In addition, a discharge mechanism may be provided in the bottle container 40B to discharge toner from the bottle container 40B. Further, the discharge mechanism may be configured to engage with the printer body <NUM> and receive a driving force from the printer body <NUM>.

In addition, the shutter member <NUM> may be omitted from any of the toner packs, and a shutter member of a sliding type may be used instead of the shutter member <NUM> of a rotary type. In addition, the shutter member <NUM> may be configured to be broken when attaching the toner pack to the replenishment port 32a or rotating the toner pack in the attached state, or may be a detachable lid structure such as a sticker.

Next, a method for detecting the toner remainder amount of the developer container <NUM> will be described with reference to <FIG>. A first toner remainder amount sensor <NUM> and a second toner remainder amount sensor <NUM> that detect a state corresponding to the toner remainder amount in the developer container <NUM> are provided in the developing apparatus <NUM> of the present embodiment.

The first toner remainder amount sensor <NUM> includes a light emitting portion 51a and a light receiving portion 51b, and the second toner remainder amount sensor <NUM> includes a light emitting portion 52a and a light receiving portion 52b. <FIG> is a circuit diagram illustrating an example of a circuit configuration of the toner remainder amount sensors <NUM> and <NUM>. To be noted, the circuit configuration of the first toner remainder amount sensor <NUM> will be described below, and description of the circuit configuration of the second toner remainder amount sensor <NUM> will be omitted.

Although an LED is used as the light emitting portion 51a, and a phototransistor that is switched to an ON state by light from the LED is used as the light receiving portion 51b in <FIG>, this is not limiting. For example, a halogen lamp or fluorescent light may be used as the light emitting portion 51a, and a photodiode or an avalanche photodiode may be used as the light receiving portion 51b. To be noted, an unillustrated switch is provided between the light emitting portion 51a and a power source voltage Vcc, and by switching the switch on, the voltage from the power source voltage Vcc is applied to the light emitting portion 51a, and the light emitting portion 51a takes a power-supplied state. Meanwhile, an unillustrated switch is also provided between the light receiving portion 51b and the power source voltage Vcc, and by switching the switch on, the light receiving portion 51b takes a power-supplied state in accordance with a current corresponding to the amount of detected light.

The light emitting portion 51a is connected to the power source voltage Vcc and a current-limiting resistor R1, and the light emitting portion 51a emits light in accordance with a current determined by the current-limiting resistor R1. As illustrated in <FIG>, the light emitted from the light emitting portion 51a passes through an optical path Q1, and is received by the light receiving portion 51b. A collector terminal of the light receiving portion 51b is connected to the power source voltage Vcc, and an emitter terminal thereof is connected to a detection resistor R2. The light receiving portion 51b that is a phototransistor receives light emitted from the light emitting portion 51a, and outputs a signal (current) corresponding to the amount of received light. This signal is converted into a voltage V1 by the detection resistor R2, and is input to an A/D conversion portion <NUM> of a control portion <NUM> (see <FIG>). To be noted, the light receiving portion 52b of the second toner remainder amount sensor <NUM> receives light emitted from the light emitting portion 52a and having passed through an optical path Q2, and a voltage V2 corresponding to the amount of received light is output and input to the A/D conversion portion <NUM> of the control portion <NUM>.

The control portion <NUM> (CPU <NUM>) determines, on the basis of the input voltage level, whether or not the light receiving portions 51b and 52b have received light from the light emitting portions 51a and 51b. The control portion <NUM> (CPU <NUM>) calculates the toner amount in the developer container <NUM> on the basis of the length of time in which each light is detected by the light receiving portion 51b and 52b and the light intensity of the received light when the toner in the developer container <NUM> is agitated for a certain time by the agitation member <NUM>. That is, the ROM <NUM> stores in advance a table that can output a toner remainder amount in accordance with the light reception time and the light intensity of the time when the toner is conveyed by the agitation member <NUM>, and the control portion <NUM> estimates/calculates the toner remainder amount on the basis of the input to the A/D conversion portion <NUM> and the table.

More specifically, the optical path Q1 of the first toner remainder amount sensor <NUM> is set to cross a rotation trajectory T of the agitation member <NUM>. In addition, time in which light in the optical path Q1 is blocked by toner hit up by the agitation member <NUM>, that is, time in which the light receiving portion 51b does not detect the light from the light emitting portion 51a in each rotation of the agitation member <NUM> changes depending on the toner remainder amount. In addition, the received light intensity of the light receiving portion 51b also changes depending on the toner remainder amount.

That is, when the toner remainder amount is large, the optical path Q1 is more likely to be blocked by toner, thus the time in which the light receiving portion 51b receives light becomes shorter, and the received light intensity of the light received by the light receiving portion 51b becomes lower. In contrast, conversely in the case where the toner remainder amount is small, the time in which the light receiving portion <NUM>1b receives light becomes longer, and the received light intensity of the light received by the light receiving portion 51b becomes higher. Therefore, the control portion <NUM> can determine whether the toner remainder amount is at the Low level or the Mid level on the basis of the light receiving time and the received light intensity of the light receiving portion 51b as will be described later. For example, as illustrated in <FIG>, in the case where the amount of toner in the conveyance chamber <NUM> of the developer container <NUM> is small, it is determined that the toner remainder amount is at the Low level. To be noted, although the second toner remainder amount sensor <NUM> is disposed not to cross the rotation trajectory T of the agitation member <NUM> in the description above, the second toner remainder amount sensor <NUM> may be disposed to cross the rotation trajectory T of the agitation member <NUM> similarly to the first toner remainder amount sensor <NUM> described above.

In addition, the optical path Q2 of the second toner remainder amount sensor <NUM> is set to be above the rotation trajectory T so as not to cross the rotation trajectory T of the agitation member <NUM>. Further, the light receiving portion 52b of the second toner remainder amount sensor <NUM> does not detect the light from the light emitting portion 52a in the case where light in the optical path Q2 is blocked by toner, and detects the light from the light emitting portion 52a in the case where light in the optical path Q2 is not blocked by toner. Therefore, regardless of the rotation operation of the agitation member <NUM>, the control portion <NUM> determines whether or not the toner remainder amount is at a Full level on the basis of whether or not the light receiving portion 52b has received light as will be described later. For example, as illustrated in <FIG>, in the case where the amount of toner in the conveyance chamber <NUM> of the developer container <NUM> is large, it is determined that the toner remainder amount is at the Full level. To be noted, although the second toner remainder amount sensor <NUM> is disposed not to cross the rotation trajectory T of the agitation member <NUM> in the description above, the second toner remainder amount sensor <NUM> may be disposed to cross the rotation trajectory T of the agitation member <NUM> similarly to the first toner remainder amount sensor <NUM> described above.

To be noted, the detection/estimation method for the toner remainder amount is not limited to the method of optical toner remainder amount detection described with reference to <FIG>, and various known types of detection/estimation methods for toner remainder amount can be employed. For example, the toner remainder amount may be detected/estimated by disposing two or more metal plates or conductive resin sheets extending in the longitudinal direction of the developing roller on the inner wall of the developer container <NUM> serving as a frame member and measuring the electrostatic capacity between two metal plates or conductive resin sheets. Alternatively, a load cell supporting the developing apparatus <NUM> from below may be provided and the CPU <NUM> may calculate the toner remainder amount by subtracting the weight of the developing apparatus <NUM> of the case where there is no toner therein from the weight measured by the load cell. In addition, the first toner remainder amount sensor <NUM> may be omitted, and the control portion <NUM> (CPU <NUM>) may calculate the toner remainder amount from the detection result of the second toner remainder amount sensor <NUM> and the emission status of the laser light.

<FIG> is a block diagram illustrating a control system of the image forming apparatus <NUM>. The control portion <NUM> serving as a control means of the image forming apparatus <NUM> includes a CPU <NUM> serving as a calculation device, a RAM <NUM> used as a work area of the CPU <NUM>, and a ROM <NUM> storing various programs. In addition, the control portion <NUM> includes an I/O interface <NUM> serving as an input/output port connected to an external device, and the A/D conversion portion <NUM> that converts an analog signal into a digital signal.

The first toner remainder amount sensor <NUM>, the second toner remainder amount sensor <NUM>, an attachment sensor <NUM>, and an opening/closing sensor <NUM> are connected to the input side of the control portion <NUM>, and the attachment sensor <NUM> detects attachment of the toner pack <NUM> to the replenishment port 32a of the developer container <NUM>. For example, the attachment sensor <NUM> is constituted by a pressure sensor that is provided at the replenishment port 32a and outputs a detection signal by being pressed by the protrusions <NUM> of the toner pack <NUM>. In addition, the opening/closing sensor <NUM> detects whether or not the opening/closing member <NUM> has been opened with respect to the top cover <NUM>. The opening/closing sensor <NUM> is constituted by, for example, a pressure sensor or a magnetic sensor.

In addition, the control portion <NUM> is connected to the operation portion <NUM>, the image forming portion <NUM>, and a toner remainder amount panel <NUM> serving as a notification means capable of notifying information about the toner remainder amount. The operation portion <NUM> includes a display portion <NUM> capable of displaying various setting screens, physical keys, and so forth. The display portion <NUM> is constituted by, for example, a liquid crystal panel. The image forming portion <NUM> includes a motor M1 serving as a drive source that drives the photosensitive drum <NUM>, the developing roller <NUM>, the supply roller <NUM>, the agitation member <NUM>, and so forth. To be noted, the photosensitive drum <NUM>, the developing roller <NUM>, the supply roller <NUM>, and the agitation member <NUM> may be configured to be each driven by a different motor.

The toner remainder amount panel <NUM> is provided on the right side of the front surface of the casing of the printer body <NUM>, that is, on the opposite side to the operation portion <NUM> disposed on the left side as illustrated in <FIG> and <FIG>, and displays information about the toner remainder amount in the developer container <NUM>. In the present embodiment, the toner remainder amount panel <NUM> is a panel member constituted by a plurality of (in the present embodiment, three) indicators arranged in the up-down direction, and the indicators respectively correspond to the Low level, the Mid level, and the Full level.

That is, as illustrated in <FIG>, in the case where only the bottom indicator is on, it is indicated that the toner remainder amount of the developer container <NUM> is at the Low level serving as a third state. As illustrated in <FIG>, in the case where the bottom and middle indicators are on and the top indicator is off, it is indicated that the toner remainder amount of the developer container <NUM> is at the Mid level serving as a second state. In the case where all the three indicators are on as illustrated in <FIG>, it is indicated that the toner remainder amount of the developer container <NUM> is at the Full level serving as a first state. To be noted, the toner remainder amount panel <NUM> is not limited to a liquid crystal panel and may be constituted by a light source such as an LED or an incandescent lamp and a diffusing lens. To be noted, although description has been given as a notification means indicating the toner remainder amount in the example illustrated in <FIG>, this is not limiting. For example, the indication of <FIG> may indicate that toner replenishment is needed, the indication of <FIG> may indicate that toner replenishment is not needed, and the indication of <FIG> may indicate that toner has been sufficiently replenished.

Next, a toner replenishment process of replenishing the developer container <NUM> with toner in the toner pack <NUM> will be described. As illustrated in <FIG>, when the toner replenishment process is started, the control portion <NUM> determines whether or not a replenishment operation starting command has been issued (step S1). In the present embodiment, the replenishment operation starting command is a user operation through the operation portion <NUM> as illustrated in <FIG>. Specifically, the replenishment operation starting command is output by the user operating the operation portion <NUM> and thus pushing a button <NUM> in a state in which the display portion <NUM> is displaying a message prompting operation of the button <NUM>.

To be noted, at this time, since the toner pack <NUM> is attached to the replenishment port 32a of the developer container <NUM>, the opening/closing member <NUM> is open. Since the operation portion <NUM> and the replenishment port 32a are both disposed on the left side of the apparatus, the toner replenishment operation using the toner pack <NUM> can be easily performed while operating the operation portion <NUM>. In addition, when the opening/closing sensor <NUM> detects that the opening/closing member <NUM> has been opened, the control portion <NUM> prohibits and stops the image forming operation by the image forming apparatus <NUM>. Therefore, in the state in which the opening/closing member <NUM> is open, the conveyance rollers, the photosensitive drum <NUM>, the scanner unit <NUM>, and so forth of the image forming apparatus <NUM> are stopped.

To be noted, the replenishment operation starting command is not limited to the pushing operation on the button <NUM>, and the replenishment operation starting command may be a touch operation on the display portion <NUM>, or the operation starting command may be output in response to detection of the attachment of the toner pack <NUM> to the replenishment port 32a by the attachment sensor <NUM>. In addition, a sensor that detects that the shutter member <NUM> of the toner pack <NUM> has been opened may be provided, and the replenishment operation starting command may be output on the basis of the detection result of this sensor. In addition, the replenishment operation starting command may be output on the basis of detection of an opening operation on the opening/closing member <NUM> by the opening/closing sensor <NUM>. In addition, a configuration in which when the opening/closing member <NUM> is opened, the high-voltage power source applied to the process cartridge <NUM> is switched off such that only the motor M1 that drives the agitation member <NUM> can be driven may be employed.

In the case where it has been determined that the replenishment operation starting command has been issued (step S1: Yes), the control portion <NUM> initializes parameters of timers T1 and T2 that will be described later to initial values (for example, zero), and starts the timers T1 and T2 (step S2). Then, the control portion <NUM> drives the motor M1 (step S3), and the agitation member <NUM> rotates.

Next, the control portion <NUM> performs the toner remainder amount detection process (step S4). When the toner remainder amount detection process is performed, as illustrated in <FIG>, the control portion <NUM> causes the light emitting portions 51a and 52a of the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM> to emit light (step S41). Then, the control portion <NUM> converts voltages V1 and V2 respectively output from the light receiving portions 51b and 52b of the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM> into digital signals (hereinafter referred to as A/D converted values) by the A/D conversion portion <NUM> (step S42).

Next, the control portion <NUM> determines whether or not the A/D converted value of the voltage V2 indicates that light in the optical path Q2 is blocked (step S43). In the case where it is indicated that light in the optical path Q2 is blocked (step S43: Yes), the control portion <NUM> causes the toner remainder amount panel <NUM> to indicate that the toner remainder amount is at the Full level (step S44). That is, as illustrated in <FIG>, all the three indicators of the toner remainder amount panel <NUM> become on.

In the case where the A/D converted value of the voltage V2 does not indicate that light in the optical path Q2 is blocked (step S43: No), the control portion <NUM> calculates the toner remainder amount information in the developer container <NUM> on the basis of the A/D converted value of the voltage V1 (step S45). Then, the control portion <NUM> causes the toner remainder amount panel <NUM> to indicate that the toner remainder amount is at the Low level or the Mid level on the basis of the calculated toner remainder amount information (step S46). When step S44 or step S46 is completed, the toner remainder amount detection process is finished. That is, the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM> serving as detection means output remainder amount information corresponding to the amount of developer accommodated in the developer container <NUM> while the agitation member <NUM> is operating.

Next, the control portion <NUM> determines whether or not the timer T2 is at a threshold value β or more as illustrated in <FIG> (step S5). The threshold value β is a value that is set in advance, and corresponds to an interval at which the toner remainder amount detection process is repeatedly performed. To be noted, α > β holds. In the case where the timer T2 is at the threshold value β or more, (step S5: Yes), the control portion <NUM> initializes and restarts the timer T2 (step S6), and returns to step S4. That is, each time the timer T2 reaches the threshold value β, the toner remainder amount detection process (step S4) is repeatedly performed. For example, in the case where the threshold value β is set to <NUM> second, the toner remainder amount detection process is repeatedly performed every <NUM> second in steps S4, S5, and S6.

In addition, in the case where the timer T2 is less than the threshold value β (step S5: No), the control portion <NUM> determines whether or not the timer T1 is at a threshold value α or more (step S7). The threshold value α is a value that is set in advance, and corresponds to the driving time of the motor M1 and the agitation member <NUM> in the toner replenishment process. In the case where the timer T1 is less than the threshold value α (step S7: No), the process returns to step S5. In the case where the timer T1 is at the threshold value α or more (step S7: Yes), the control portion <NUM> stops the driving of the motor M1 (step S8), and finishes the toner replenishment process. For example, in the case where the threshold value α is set to <NUM> seconds, the time from when the motor M1 starts driving in step S3 to when the motor M1 is stopped in step S8 is <NUM> seconds.

In the case where toner drops from the toner pack <NUM> into the developer container <NUM> in the toner replenishment process described above as illustrated in <FIG>, the toner enters the conveyance chamber <NUM> through the first projection portion <NUM>. Since the replenishment port 32a and the first projection portion <NUM> are disposed at one end portion of the developer container <NUM> in the longitudinal direction, toner is collectively supplied to the one end portion side of the conveyance chamber <NUM>.

Here, a case where the agitation member <NUM> is not rotating when toner is supplied to the conveyance chamber <NUM> will be considered. In the case where toner is caused to drop from the toner pack <NUM> into the developer container <NUM>, if the agitation member <NUM> is not rotated in the conveyance chamber <NUM> accommodating toner, it takes time for the dropped toner to spread to the entirety of the photosensitive drum <NUM> in the longitudinal direction. If this time is long, it takes time for the user performing the toner replenishment operation to confirm that the conveyance chamber <NUM> has been replenished with toner, which degrades the usability.

Therefore, in the present embodiment, the agitation member <NUM> is driven for a predetermined time (threshold value α) since the start of replenishment in the toner replenishment process. As a result of this, as illustrated in <FIG>, toner supplied from the toner pack <NUM> to one end portion of the developer container <NUM> is quickly flattened by the agitation member <NUM> in the entirety of the conveyance chamber <NUM> of the developer container <NUM> in the longitudinal direction. Therefore, the time the user takes to confirm that toner replenishment has been performed can be shortened, and the usability can be improved. In addition, since toner accommodated in the developer container <NUM> is flattened, the precision of the toner remainder amount information from the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM> can be improved.

Then, during the toner replenishment process, the toner remainder amount information in the developer container <NUM> is detected by the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM> every predetermined time (threshold value β). For example, as illustrated in <FIG>, the user replenishes the developer container <NUM> with toner from the toner pack <NUM> in a state in which the toner remainder amount panel <NUM> indicates that the toner remainder amount is at the Low level.

Then, after the toner remainder amount panel <NUM> indicates that the toner remainder amount is at the Mid level as illustrated in <FIG>, the toner remainder amount panel <NUM> indicates that the toner remainder amount is at the Full level as illustrated in <FIG>. As a result of this, the user can reliably recognize that the developer container <NUM> has been replenished with toner from the toner pack <NUM>, and the usability can be improved.

Here, section views of <FIG> indicates 16A-16A section of <FIG>. <FIG> illustrate that the light emitting portion 52a is disposed at the right end of the photosensitive drum <NUM> in the longitudinal direction. In addition, the light emitting portion 51a and the light receiving portions 51b and 52b are disposed at the same/approximately the same position in the longitudinal direction of the photosensitive drum <NUM>. Due to sensor arrangement restriction in the apparatus body, the sensors might be arranged as illustrated in <FIG> in some cases. Also in such cases, the usability can be improved as described above by the rotation of the agitation member <NUM> in the toner replenishment.

In addition, in some cases, a sensor might be disposed approximately right under the replenishment port 32a. In such a case, as illustrated in <FIG>, more of the replenished toner might be distributed on the left side and it might take more time to flatten the toner surface in the entirety of the photosensitive drum <NUM> in the longitudinal direction. To detect the toner replenishment state accurately, the toner surface needs to be flattened in the entire region in the longitudinal direction of the photosensitive drum <NUM>. However, even in such a case, in the present embodiment, the rotation of the agitation member <NUM> in toner replenishment flattens the toner surface in the entire region in the longitudinal direction of the photosensitive drum <NUM>, and the usability can be improved.

Next, the relationship between the amount of toner charged into the toner pack <NUM> and the capacity of the developer container <NUM> will be described. The developer container <NUM> is capable of accommodating toner of Z [g] as illustrated in <FIG>. To be noted, although illustration is given in terms of grams (g) in <FIG>, the unit may be converted into a unit indicating capacity such as milliliters (ml).

In the case where the developer container <NUM> accommodates toner of <NUM> [g] to X [g], the toner remainder amount panel <NUM> indicates the Low level on the basis of the detection results of the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM>. X [g] corresponds to a second amount, and the toner amount of <NUM> [g] to X [g] corresponds to a toner amount smaller than the second amount.

In the case where the developer container <NUM> accommodates toner of X [g] to Y [g], the toner remainder amount panel <NUM> indicates the Mid level on the basis of the detection result of the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM>. Y [g] corresponds to a first amount, and a toner amount of X [g] to Y [g] corresponds to a toner amount smaller than the first amount.

In the case where the developer container <NUM> accommodates toner of Y [g] or more, the toner remainder amount panel <NUM> indicates the Full level on the basis of the detection result of the first toner remainder amount sensor <NUM> and the second toner remainder amount sensor <NUM>. The toner amount of Y [g] or more corresponds to a toner amount of first amount or more.

<FIG> is a graph indicating the toner amount in the case where the developer container <NUM> is replenished with toner by using the toner pack <NUM> filled with toner of A [g]. <FIG> is a graph indicating the toner amount in the case where the developer container <NUM> is replenished with toner by using the toner pack <NUM> filled with toner of B [g] (> A). To be noted, the product lineup of the toner pack <NUM> may include either one or both of a toner pack of a small capacity filled with toner of only A [g] and a toner pack of a large capacity filled with toner of B [g]. In addition, the product lineup of the toner pack <NUM> is not limited to <NUM>, and <NUM> or more kinds may be prepared.

In the present embodiment, the amount of toner (A, B) charged into the toner pack <NUM> serving as a replenishment container satisfies the following formulae (<NUM>) and (<NUM>). <MAT> <MAT>.

As illustrated in <FIG>, if the developer container <NUM> is replenished with toner of just A [g] by the toner pack <NUM> in the case where toner remaining in the developer container <NUM> is R [g] in the range of <NUM> [g] to X [g], the developer container <NUM> accommodates toner of (R + A) [g]. Since Y < (R + A) is satisfied according to the formula (<NUM>) described above, the toner remainder amount panel <NUM> after the toner replenishment indicates the Full level. That is, the threshold value Y [g] of the Full level is smaller than the replenishment amount A [g] supplied from the toner pack <NUM>.

In addition, as illustrated in <FIG>, if the developer container <NUM> is replenished with toner of B [g] by the toner pack <NUM> in the case where toner remaining in the developer container <NUM> is R [g], the developer container <NUM> accommodates toner of (R + B) [g]. Since Y < (R + B) is satisfied according to the formula (<NUM>) described above, the toner remainder amount panel <NUM> after the toner replenishment indicates the Full level.

As described above, the capacity of the developer container <NUM> is set such that the toner remainder amount panel <NUM> always indicates the Full level in the case where toner replenishment is performed when the toner remainder amount panel <NUM> indicates the Mid level or the Low level. To be noted, the capacity of the developer container <NUM> does not have to be set such that the single toner pack <NUM> achieves the Full level, and for example, the Full level may be achieved by replenishment using a plurality of toner packs <NUM> each accommodating a small amount of toner.

In addition, the capacity of the developer container <NUM> is, according to the formulae (<NUM>) and (<NUM>) described above, set such that all toner charged into the toner pack <NUM> can move to the developer container <NUM> when the toner remainder amount panel <NUM> indicates the Mid level or the Low level. That is, the maximum amount Z [g] of the developer that can be accommodated in the developer container <NUM> is larger than a value obtained by adding the amount (A [g] or B [g]) of developer accommodated in the toner pack <NUM> to Y [g], which is the boundary between the Full level and the Mid level. In other words, the amount of toner charged into the toner pack <NUM> is smaller than the difference between the maximum amount of toner (Z [g]) that can be accommodated in the developer container <NUM> and the toner remainder amount (Y [g]) that is the boundary between the Mid level and the Full level.

As a result of this, the developer container <NUM> does not become full of toner while replenishing the developer container <NUM> with toner by using the toner pack <NUM>, and leakage of toner from the replenishment port 32a during toner replenishment can be suppressed.

As described above, in the present embodiment, the second opening portion 82a is defined in the discharge tray <NUM> of the top cover <NUM>, and the opening/closing member <NUM> openably and closably provided on the top cover <NUM>. The opening/closing member <NUM> covers the second opening portion 82a in a closed state, and exposes the replenishment port 32a of the developer container <NUM> in an open state. Therefore, the user can access the replenishment port 32a by just opening the opening/closing member <NUM>.

In the present embodiment, since the system (direct replenishment system) in which the developer container <NUM> is replenished with toner directly from the toner pack <NUM> through the replenishment port 32a is employed, the process cartridge <NUM> does not have to be taken out when replenishing the developer container <NUM> with toner. In addition, the replenishment port 32a of the developer container <NUM> is defined in the upper surface of the first projection portion <NUM> projecting upward from one end portion of the conveyance chamber <NUM> in the longitudinal direction, and is thus disposed in the vicinity of the second opening portion 82a. Therefore, the user can easily perform the toner replenishment operation on the developer container <NUM> through the replenishment port 32a. In addition, parts such as the developing roller <NUM> and the supply roller <NUM> are not replaced when replenishing the developer container <NUM> with toner, and thus the cost can be reduced.

In addition, since the laser passage space SP is formed to be surrounded by the first projection portion <NUM>, the second projection portion <NUM>, the grip portion <NUM>, and the conveyance chamber <NUM>, the developer container <NUM> and the scanner unit <NUM> can be disposed in the vicinity of each other, and thus the image forming apparatus <NUM> can be miniaturized.

Further, when attaching the toner pack <NUM> to the replenishment port 32a and performing the toner replenishment operation, since the agitation member <NUM> is driven, the packing phenomenon can be suppressed even if the replenishment port 32a is disposed on the one end side of the developer container <NUM> in the longitudinal direction. As a result of this, image defects can be reduced, and the detection precision of the toner remainder amount information can be improved.

In addition, the maximum amount Z [g] of the developer that can be accommodated by the developer container <NUM> is set to be larger than a value obtained by adding the amount (A [g] or B [g]) of developer accommodated by the toner pack <NUM> to Y [g], which is the boundary between the Full level and the Mid level. Therefore, the developer container <NUM> does not become full of toner while replenishing the developer container <NUM> with toner by using the toner pack <NUM>, and leakage of toner from the replenishment port 32a during toner replenishment can be suppressed. By configuring the image forming apparatus <NUM> in this manner, a mode of an image forming apparatus that can satisfy the needs of the user can be provided.

To be noted, although the agitation member <NUM> is driven for a predetermined time (threshold value α) on the basis of operation of the button <NUM> of the operation portion <NUM> by the user in the toner replenishment process in the present embodiment, this is not limiting. For example, the driving of the agitation member <NUM> may be started by pushing the button <NUM> once, and the driving of the agitation member <NUM> may be stopped by pushing the button <NUM> again. Alternatively, the agitation member <NUM> may be driven only while the button <NUM> is pushed.

In addition, the display portion <NUM> may display a replenishment notification for prompting toner replenishment when the toner remainder amount of the developer container <NUM> reaches the Low level. In addition, a replenishment notification for prompting toner replenishment may be displayed on the display portion <NUM> when the toner is run out.

In addition, although the toner remainder amount of the developer container <NUM> is notified to the user by the toner remainder amount panel <NUM>, the three-indicator configuration like the present embodiment does not have to be employed. For example, the toner remainder amount panel <NUM> may be constituted by one indicator, two indicators, four indicators, or more indicators. In addition, a configuration in which the toner remainder amount is continuously indicated by percentage presentation or gauge presentation. In addition, the notification of the toner remainder amount to the user may be performed by sound by using a loudspeaker.

<FIG> illustrates a first modification example of the first embodiment. As illustrated in <FIG>, in an image forming apparatus 1B, a replenishment port 132a of a developer container is disposed on the right side of the apparatus, and an opening/closing member 83B is disposed on the right side of the apparatus. The opening/closing member 83B exposes the replenishment port 132a in an open state, and covers the replenishment port 132a in a closed state. By disposing the replenishment port 132a on the right side of the apparatus as described above, the replenishment port 132a is positioned in the vicinity of the toner remainder amount panel <NUM>. Therefore, the toner remainder amount panel <NUM> can be easily checked when replenishing the developer container with toner using the toner pack <NUM>.

In addition, the configuration is not limited to the embodiment illustrated in <FIG>, and as illustrated in <FIG>, the present invention may be applied to an image forming apparatus 1C configured such that an opening/closing member 83C is opened to the front.

In addition, as illustrated in <FIG>, the present invention may be applied to an image forming apparatus 1D configured such that an opening/closing member 83D is opened to the rear side.

In addition, as illustrated in <FIG>, an operation portion 300E may be disposed in the reading apparatus <NUM> instead of in the printer body <NUM>, or may be disposed on the right side of the apparatus together with the toner remainder amount panel <NUM>. To be noted, as a matter of course, the operation portion 300E and the toner remainder amount panel <NUM> may be both disposed on the right side of the apparatus.

In addition, as illustrated in <FIG>, a toner remainder amount panel 400F may be disposed on the left side of the apparatus, and an operation portion 300F may be disposed on the right side of the apparatus.

In the second embodiment, the configuration of the replenishment port 32a is changed from the first embodiment. Therefore, elements substantially the same as in the first embodiment will be denoted by the same reference signs in the drawings, or the illustration thereof will be omitted.

As illustrated in <FIG>, in an image forming apparatus <NUM>, an opening/closing member <NUM> is openably and closably supported by the top cover <NUM>, and the opening/closing member <NUM> is configured to be opened to the rear side of the apparatus. By opening the opening/closing member <NUM>, a replenishment port 232a of a developer container <NUM> is exposed. Further, the replenishment port 232a opens downstream and upward in the discharge direction of the discharge roller pair <NUM> so as to be inclined with respect to the vertical direction. In other words, the replenishment port 232a opens obliquely toward the upper front side.

By configuring the replenishment port 232a in this manner, the toner pack <NUM> becomes inclined toward the front side in the state of being attached to the replenishment port 232a. Therefore, the space between the replenishment port 232a and the reading apparatus <NUM> can be utilized efficiently, and also a toner pack of a large capacity can be attached to the replenishment port 232a.

To be noted, as illustrated in <FIG>, an opening/closing member <NUM> and the reading apparatus <NUM> may be configured to be held at a less steep angle than in <FIG>. By employing such a configuration, the installation space for the image forming apparatus <NUM> can be reduced.

Next, a third embodiment of the present invention will be described. In the third embodiment, the configuration of the cartridge guides <NUM> is changed from the first embodiment. Therefore, elements substantially the same as in the first embodiment will be denoted by the same reference signs in the drawings, or the illustration thereof will be omitted.

As illustrated in <FIG>, an image forming apparatus 1J includes a printer body 100J and a reading apparatus <NUM>, and the printer body 100J includes cartridge guides 102J. The cartridge guides 102J slide on projection portions 21a (see <FIG>) provided at end portions of the photosensitive drum <NUM> in the axial direction, and thus guide the process cartridge <NUM> when drawing out the process cartridge <NUM>.

Draw-out stoppers 102Ja are formed at the downstream ends of the cartridge guides 102J in the draw-out direction. Therefore, when the user draws out the process cartridge <NUM> as illustrated in <FIG>, the projection portions 21a of the process cartridge <NUM> abut the draw-out stoppers 102Ja, and thus the process cartridge <NUM> is not detached from the printer body 100J. To be noted, unillustrated rotation stoppers are provided in the vicinity of the draw-out stoppers 102Ja, and the process cartridge <NUM> is held by the rotation stoppers so as not to rotate in the state of abutting the draw-out stoppers 102Ja.

As described above, in a state in which the process cartridge <NUM> is drawn out along the cartridge guides 102J, the replenishment port 32a is positioned on the front side of the image forming apparatus 1J as illustrated in <FIG>, <FIG>. Therefore, the toner replenishment operation of replenishing the developer container <NUM> with toner through the replenishment port 32a by using the toner pack <NUM> can be easily performed. In addition, since a large space is provided right above the replenishment port 32a, a toner pack of a large capacity can be attached to the replenishment port 32a. To be noted, all the embodiments and modification examples described above may be combined appropriately.

To be noted, although the reading apparatus <NUM> is provided above the printer body in all the embodiments described above, this is not limiting. That is, the image forming apparatus may be a printer that does not include a reading apparatus. In addition, the reading apparatus may be a reading apparatus that includes an auto document feeder (ADF) that feeds a document.

The present invention is applicable to, for example, image forming apparatuses such as printers, copiers, facsimile machines, and multifunctional apparatuses including functions of these. Particularly, the present invention is applicable to an image forming apparatus including a developer container to and from which a replenishment container accommodating developer for replenishment is attachable and detachable.

Claim 1:
An image forming apparatus (<NUM>) to and from which a replenishment container (<NUM>) accommodating developer is attachable and detachable and which is configured to execute an image formation in which a developer image is formed on a recording material, the image forming apparatus (<NUM>) comprising:
an image bearing member (<NUM>) configured to rotate while bearing the developer image;
a developer bearing member (<NUM>) configured to bear the developer and supply the developer to the image bearing member (<NUM>);
a developer container (<NUM>) including:
an accommodating portion (<NUM>) configured to accommodate the developer to be borne on the developer bearing member (<NUM>); and
a replenishment port (32a) to and from which the replenishment container (<NUM>) is attachable and detachable and through which the accommodating portion (<NUM>) is replenished with the developer from the replenishment container (<NUM>);
an agitation member (<NUM>) configured to agitate the developer accommodated in the accommodating portion (<NUM>);
an opening/closing member (<NUM>) configured to be movable between a closed position where the opening/closing member (<NUM>) closes the replenishment port (32a) such that the replenishment container (<NUM>) is not attachable to the developer container (<NUM>), and an open position where the opening/closing member (<NUM>) opens the replenishment port (32a) such that the replenishment container (<NUM>) is attachable to the developer container (<NUM>) ;
an opening/closing sensor (<NUM>) configured to detect whether the opening/closing member (<NUM>) is at the open position or at the closed position; and
a control means (<NUM>) configured to control driving of the agitation member (<NUM>),
characterized in that
an execution of the image formation is possible when the opening/closing sensor (<NUM>) detects that the opening/closing member (<NUM>) is at the closed position, and the execution of the image formation is not possible and the driving of the agitation member (<NUM>) is possible when the opening/closing sensor (<NUM>) detects that the opening/closing member (<NUM>) is at the open position.