JP2022126022A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can prevent leakage of developer when a large amount of developer is supplied from a developer storage container at a time.SOLUTION: An image forming apparatus comprises: an image carrier; a developing device; a developer storage container; and a shield sheet. The developing device has a developer container that stores one-component developer and a developer carrier that carries the developer, and develops an electrostatic latent image formed on the image carrier into a toner image. The developer storage container has a cylindrical container body that has a developer supply port for discharging the developer formed in its outer peripheral surface, and a shutter that is movably mounted on the container body and is movable to a plurality of positions including an opening position for opening the developer supply port and a closing position for closing the developer supply port. The shield sheet is selectively arranged, with the movement of the shutter, to a shield position for partitioning the inside of the developer container into a first area close to the image carrier and a second area distant from the image carrier and a retracted position retracted from the shield position.SELECTED DRAWING: Figure 5

Description

The present invention relates to image forming apparatuses such as copiers, facsimiles, and printers, and more particularly to a developer supply mechanism for supplying developer from a developer container to a developing device.

2. Description of the Related Art Conventionally, in a one-component developing device using a one-component developer consisting of only magnetic or non-magnetic toner, which is mounted in an image forming apparatus, a certain amount of one-component developer is stored in the developing device for ease of maintenance. (hereinafter simply referred to as toner) is filled, and when the developer runs out, the entire developing device is replaced. However, from an economical point of view, the developing device cannot be replaced frequently, and in order to form a certain number of images, the capacity of the developer must be increased. . Therefore, in order to reduce the size of the developing device, there has been proposed a developing device that replenishes the developer using a developer storage container such as a toner container or toner cartridge provided separately from the developing device.

In the replenishment method as described above, the developer in the developing device and the developer in the developer storage container are different in condition, which may cause charging failure, resulting in a so-called fogging phenomenon. Therefore, in order to stir the new developer replenished from the developer storage container and the old developer remaining in the developing device, a screw and a stirring paddle are arranged in the developer storage container and drive control is performed. often In that case, a screw, agitating paddle, etc. are required in the developer container, and a motor for driving them is also required. Furthermore, there is a problem that control for driving them is required, leading to an increase in cost of the image forming apparatus and complication of control.

Therefore, after the toner in the developing device is used up, a method of replenishing the developing device with new toner from the developer storage container at once is conceivable. In this replenishing method, the new developer replenished from the developer storage container and the old developer remaining in the developing device are not mixed, and problems such as fogging are less likely to occur. On the other hand, since it is necessary to replenish a large amount of developer at one time, there is a problem that the replenished developer scatters in the developing device and leaks out from the gaps of the developing device to contaminate the inside of the image forming apparatus.

As a method for preventing the scattering of the developer when replenishing the developer, for example, Japanese Patent Laid-Open No. 2002-100001 discloses a developer containing portion having an opening for replenishing the developer, and a developer contained in the developer containing portion. developer conveying means for conveying; a lid body provided movably between a first position covering the opening of the developer containing portion and a second position opening the opening; and a lid body positioned at the second position. With the operation of arranging the developer accommodating portion and the developer conveying means at the first position, the developer accommodating portion and the developer conveying means are shielded from each other, and with the operation of arranging the lid body at the first position, the developer accommodating portion and the developer conveying means are separated from each other. A developing device having a partition wall member communicating therebetween is disclosed.

Further, in Patent Document 2, a layer thickness regulating member is provided for an upstream gap, which is located on the upstream side in the rotation direction of the developer holder, among the gaps formed between the developer holder and the developing housing. , and is provided for the downstream gap located on the downstream side. a sealing member whose widthwise upstream side is fixed to the developing housing, and whose widthwise downstream side contacts the developer on the developer holding member to seal the gap on the downstream side. is disclosed.

Japanese Utility Model Laid-Open No. 5-15059 JP 2016-180829 A

In the configuration of Patent Document 1, since the partition member moves along with the movement of the cover of the developing device, it is impossible to shield the developer according to the replenishment timing of the developer from the developer container. Further, in the configuration of Patent Document 2, the layer thickness regulating member and the sealing member regulate the leakage of the developer from the gap between the developer holder and the developing housing. When replenishing, the developer may leak out.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus capable of suppressing developer leakage when a large amount of developer is replenished from a developer container at once.

A first configuration of the present invention to achieve the above object is an image forming apparatus including an image carrier, a developing device, a developer container, and a shielding sheet. An electrostatic latent image is formed on the surface of the image carrier. The developing device includes a developing container that stores a one-component developer consisting of only toner to be supplied to the image carrier, and a developer carrier that is rotatably supported by the developing container so as to face the image carrier and carries the developer. and for developing an electrostatic latent image formed on the image carrier into a toner image. The developer containing container is detachable from the developing device, and contains a developer to be supplied to the developing device. , is mounted movably in the circumferential direction along the inner peripheral surface of the container body, and is movable to a plurality of positions including an open position for opening the developer supply port and a closed position for closing the developer supply port. and a shutter. The shielding sheet is selected between a shielding position that divides the inside of the developer container into a first area close to the image carrier and a second area far from the image carrier, and a retraction position retracted from the shielding position as the shutter moves. placed. By moving the shutter to the open position to open the developer supply port, the shielding sheet is arranged at the shielding position, and the entire amount of the developer contained in the container main body is transferred to the second area of the developer container at once. By replenishing and moving the shutter from the open position, the shielding sheet moves from the shielding position to the retracted position.

According to the first configuration of the present invention, when replenishing the developer from the developer container to the developing device, the developer in the developing device is used up, and then the entire amount of developer in the developer container is replenished at once. . Therefore, the developer remaining in the developing device and the new developer in the developer storage container do not have charging failure due to different conditions, and the fogging phenomenon can be suppressed. In addition, since the shielding sheet is arranged at the shielding position by moving the shutter to the open position, the scattering path of the developer in the developing container can be shielded when replenishing the developer. scattering of the developer can be suppressed. Furthermore, since the shielding sheet moves from the shielding position to the retracted position by moving the shutter from the open position, there is no fear that the shielding sheet will interfere with the printing operation.

Schematic cross-sectional view of an image forming apparatus 100 according to an embodiment of the present invention FIG. 2 is a block diagram showing an example of a control path of the image forming apparatus 100; FIG. 4 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 according to the first embodiment of the present invention, and showing the state immediately after the toner container 5 is replaced; 3 is a perspective view of the toner container 5 in the state of FIG. FIG. 4 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the first embodiment, showing a state in which the shutter 53 of the toner container 5 is opened; 5 is a perspective view of the toner container 5 in the state of FIG. FIG. 4 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the first embodiment, showing a state during a printing operation; FIG. 4 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the first embodiment, showing a state in which the toner in the developing device 4 is empty; FIG. 10 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 according to the second embodiment of the present invention, showing the state immediately after the toner container 5 is replaced; FIG. 10 is a view of the rear side of the developing device 4 and the toner container 5 shown in FIG. 9 as seen from the inside of the developing device 4; FIG. 4 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the second embodiment, showing a state in which the shutter 53 of the toner container 5 is opened; FIG. 11 is a view of the rear side of the developing device 4 and the toner container 5 shown in FIG. 11 as seen from the inside of the developing device 4; FIG. 10 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the second embodiment, showing a state during a printing operation; FIG. 10 is a side cross-sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 of the second embodiment, showing a state in which the toner in the developing device 4 is empty;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 according to one embodiment of the invention. An image forming unit P that forms a monochrome image through each process of charging, exposing, developing, and transferring is arranged in the main body of the image forming apparatus (eg, monochrome printer) 100 .

The image forming section P includes a charging section 2, an exposure unit 3, a developing device 4, a transfer roller 7, a cleaning device 8, and a static elimination device along the rotation direction of the photosensitive drum 1 (counterclockwise direction in FIG. 1). (not shown) are provided. In the image forming section P, the image forming process for the photosensitive drum 1 is executed while rotating the photosensitive drum 1 counterclockwise in FIG.

The photosensitive drum 1 is, for example, an aluminum drum on which a photosensitive layer is laminated. Then, an electrostatic latent image is formed on the surface receiving the laser beam from the exposure unit 3, which will be described later, with the charge attenuated. The above-mentioned photosensitive layer is not particularly limited, but for example, amorphous silicon (a-Si) having excellent durability, or an organic photosensitive layer ( OPC) and the like are preferable.

The charging section 2 uniformly charges the surface of the photosensitive drum 1 . For example, as the charging unit 2, a corona discharge device that discharges by applying a high voltage to thin wires or the like as electrodes is used. Instead of the corona discharge device, a contact type charging device that applies a voltage while a charging member such as a charging roller is in contact with the surface of the photoreceptor may be used. The exposure unit 3 irradiates the photosensitive drum 1 with a light beam (for example, a laser beam) based on the image data received by the image input unit 70 (see FIG. 2) to form an electrostatic latent image on the surface of the photosensitive drum 1. Form.

The developing device 4 adheres toner to the electrostatic latent image on the photosensitive drum 1 to form a toner image. Toner is supplied to the developing device 4 from a toner container 5 . Here, the developing device 4 contains a magnetic one-component developer (toner) composed only of toner components having magnetism. Further, detailed configurations of the developing device 4 and the toner container 5 will be described later.

The transfer roller 7 transfers the toner image formed on the surface of the photosensitive drum 1 onto a sheet conveyed along the sheet conveying path 11 without disturbing the toner image. The cleaning device 8 includes a cleaning roller, a cleaning blade, etc., which make linear contact with the photosensitive drum 1 in the longitudinal direction, and removes residual toner on the surface of the photosensitive drum 1 after the toner image is transferred to the paper.

When performing a printing operation, image data transmitted from a host device such as a personal computer to the image input unit 70 (see FIG. 2) is converted into an image signal. On the other hand, in the image forming section P, the charging section 2 uniformly charges the surface of the photosensitive drum 1 rotating counterclockwise in the figure. Then, the exposure unit 3 emits a laser beam (light beam) onto the photosensitive drum 1 based on the image data, thereby forming an electrostatic latent image on the surface of the photosensitive drum 1 based on the image data. Thereafter, the developing device 4 adheres toner to the electrostatic latent image to form a toner image.

A sheet of paper is conveyed at a predetermined timing from the sheet containing section 10 through the sheet conveying path 11 and the pair of registration rollers 13 toward the image forming section P on which the toner image is formed as described above. The toner image on the surface of the photosensitive drum 1 is transferred to the paper by the transfer roller 7 . Then, the paper having the toner image transferred thereon is separated from the photosensitive drum 1, conveyed to the fixing section 9, and heated and pressurized to fix the toner image on the paper.

The paper that has passed through the fixing section 9 is sorted in the direction of conveyance by a switching guide 16 arranged at a branch of the paper conveyance path 11, and is sent to the reverse conveyance path 17 as it is (or after being sent to the reverse conveyance path 17 and subjected to double-sided printing). , and the pair of discharge rollers 14 to the paper discharge section 15 .

FIG. 2 is a block diagram showing an example of control paths used in the image forming apparatus 100. As shown in FIG. Since various parts of the apparatus are controlled when the image forming apparatus 100 is used, the overall control path of the image forming apparatus 100 is complicated. Therefore, here, the portion of the control path that is necessary for implementing the present invention will be mainly described.

The control unit 90 includes a CPU (Central Processing Unit) 91 as a central processing unit, a read-only memory (ROM) 92, a readable/writable memory (RAM) (Random Access Memory) 93, a temporary a temporary storage unit 94 for temporarily storing image data, etc.; At least an F (interface) 96 is provided.

The ROM 92 stores a program for controlling the image forming apparatus 100 and data such as numerical values necessary for control that are not changed while the image forming apparatus 100 is in use. The RAM 93 stores necessary data generated during control of the image forming apparatus 100, data temporarily necessary for controlling the image forming apparatus 100, and the like. The RAM 93 also stores the initial toner storage amount of the toner container 5, the printing rate P for each image from the start of use of the toner container 5, and the like, which are used to detect the remaining amount of toner in the developing device 4, which will be described later. ing.

Further, the control unit 90 transmits a control signal from the CPU 91 to each part and device in the image forming apparatus 100 through the I/F 96 . Signals and input signals indicating the state of each part and device are transmitted to the CPU 91 through the I/F 96 . The parts and devices controlled by the control section 90 include, for example, the image forming section P, the fixing section 9, the voltage control circuit 61, the image input section 70, the operation section 80, and the like.

The calculation unit 97 calculates the printing rate P for each image based on the digital signal (image data) in the temporary storage unit 94 . The calculated print rate P is stored in the RAM 93 . Then, the toner consumption amount is calculated based on the cumulative printing rate ΣP obtained by accumulating the printing rates P. Further, the toner remaining amount in the developing device 4 is detected by subtracting the calculated toner consumption amount from the initial value of the toner replenishment amount replenished in the developing device 4 . The detected remaining amount of toner is used to detect replacement timing of the toner container 5, which will be described later.

The voltage control circuit 61 is connected to a charging voltage power source 62, a developing voltage power source 63, and a transfer voltage power source 64, and operates these power sources according to output signals from the control section 90. These power sources are voltage controlled. The control signal from the circuit 61 causes the charging voltage power source 62 to the charging section 2, the developing voltage power source 63 to the developing roller 43 (see FIG. 3) in the developing device 4, and the transfer voltage power source 64 to transfer roller 7, respectively. voltage is applied.

The image input unit 70 is a receiving unit that receives image data transmitted from a personal computer or the like. The image signal input from the image input section 70 is converted into a digital signal and sent to the temporary storage section 94 .

The operation unit 80 is provided with a liquid crystal display unit 81 and LEDs 82 indicating various states, and is designed to indicate the state of the image forming apparatus 100, the state of image formation, and the number of copies to be printed. Various settings of the image forming apparatus 100 are performed from the printer driver of the personal computer.

In addition, the operation unit 80 includes a start button for instructing the user to start image formation, a stop/clear button for use when stopping image formation, and a button for setting various settings of the image forming apparatus 100 to the default state. A reset button, etc., used for

FIG. 3 is a side sectional view schematically showing the developing device 4 and the toner container 5 mounted in the image forming apparatus 100 according to the first embodiment of the invention. 4 is a perspective view of the toner container 5. FIG. As shown in FIG. 3 , the developing device 4 has a developer container 41 , a developing roller 43 , a regulating blade 45 and a stirring paddle 47 . Toner supplied from the toner container 5 is stored in the developer container 41 . A container mounting portion 41 a to which the toner container 5 is mounted is formed on the upper portion of the developing container 41 .

The developing roller 43 is rotatably supported by the developer container 41 . A permanent magnet (not shown) having a plurality of N and S magnetic poles is fixed inside the developing roller 43 . The magnetic force of the magnet causes the toner to adhere (carry) on the surface of the developing roller 43 to form a thin toner layer. A part of the outer peripheral surface of the developing roller 43 is exposed from the developer container 41, and the exposed part is arranged so as to face the photosensitive drum 1 (see FIG. 1). Developing roller 43 on which a thin toner layer is formed rotates according to the rotation of photoreceptor drum 1 , thereby supplying toner to photoreceptor drum 1 .

The regulating blade 45 is formed so that its longitudinal direction (the direction perpendicular to the paper surface of FIG. 3) is larger than the maximum developing width of the developing roller 43, and is arranged at a predetermined distance from the developing roller 43. The amount of toner supplied to the photosensitive drum 1 is regulated. The gap (layer thickness regulating portion) between the developing roller 43 and the regulating blade 45 is set to approximately 0.2 mm to 0.4 mm. As the material of the regulating blade 45, magnetic or non-magnetic SUS (stainless steel) or the like is used.

The stirring paddle 47 is rotatably supported by the developer container 41 about a support shaft 47a. By rotating the stirring paddle 47 counterclockwise in FIG. 3, the toner in the developer container 41 is stirred and supplied to the developing roller 43 .

The toner container 5 has a cylindrical container body 51 , a shutter 53 and a shielding sheet 55 . The container main body 51 stores the toner T to be supplied to the developing device 4 . A toner replenishing port 51 a is opened on the bottom surface of the container body 51 . The toner supply port 51a is formed over substantially the entire area in the axial direction (longitudinal direction) of the container main body 51, and is formed in a range that can be accommodated inside the container mounting portion 41a of the developer container 41 in the circumferential direction of the container main body 51. It is

The shutter 53 is slidably provided along the inner peripheral surface of the container body 51, and an operation lever 53a is provided at a position facing one side (the left side in FIG. 4) of the container body 51. . An end portion of the operating lever 53 a protrudes outside the container body 51 through an annular guide groove 51 b formed in the side surface of the container body 51 . By gripping the operation lever 53a and moving it along the guide groove 51b, the shutter 53 is moved in the circumferential direction to open and close the toner supply port 51a.

The guide groove 51b is formed with engagement portions 57a and 57b protruding inward from the outer peripheral edge. The engaging portions 57a and 57b provide a click feeling (operation feeling) by engaging with the operating lever 53a. This click feeling makes it possible to easily recognize that the operating lever 53a has been positioned at the desired position.

The shielding sheet 55 is connected to the upstream end of the shutter 53 in the movement direction (counterclockwise direction in FIG. 3). A polyethylene terephthalate (PET) film or the like is used as the material of the shielding sheet 55 .

Next, a procedure for supplying toner from the toner container 5 to the developing device 4 in the image forming apparatus 100 of the first embodiment will be described. FIG. 3 shows the state immediately after the body cover (not shown) of the image forming apparatus 100 is opened and the toner container 5 is replaced with a new one. FIG. 4 shows the toner container 5 in the state of FIG. 3, and the shutter 53 is arranged at the closing position for closing the toner supply port 51a.

FIG. 5 shows a state in which the shutter of the toner container 5 is opened from the state shown in FIG. 6 is a perspective view of the toner container 5 in the state of FIG. 5. FIG. After the toner container 5 is attached to the container attachment portion 41a of the developing device 4, as shown in FIG. 5, the operation lever 53a is moved counterclockwise to the position of the engagement portion 57a (see FIG. 3), thereby opening the shutter. 53 moves to the open position to open the toner supply port 51a. Further, as the shutter 53 moves, the shielding sheet 55 moves to a position overlapping the toner supply port 51a.

As a result, the shielding sheet 55 is pushed by the toner T in the toner container 5 and hangs down inside the developer container 41 , and the shielding sheet 55 causes the inside of the developer container 41 to move toward the side of the developer container 41 closer to the photosensitive drum 1 ( It is divided into a first region R1 on the side where the developing roller 43 and the regulating blade 45 are arranged, and a second region R2 on the side far from the photosensitive drum 1 (on the side of the container mounting portion 41a). Further, the toner supply port 51a is opened, and the entire amount of the toner T in the toner container 5 is supplied to the second area R2 in the developer container 41 at once. As a result, scattering of toner from the gap between the developing container 41 and the developing roller 43 or the regulating blade 45 can be suppressed.

FIG. 7 is a side sectional view schematically showing the developing device 4 and the toner container 5 during printing operation. In the state of FIG. 5, the inside of the developing container 41 is divided into the first region R1 and the second region R2 by the shielding sheet 55, so that the toner T supplied to the second region R2 is transferred to the developing roller in the first region R1. 43, and the developing device 4 cannot be used. Therefore, as shown in FIG. 7, by moving the operating lever 53a counterclockwise from the engaging portion 57a to the position (recovery position) of the engaging portion 57b (see FIG. 3), the shutter 53 is further rotated counterclockwise. move to

As a result, the shielding sheet 55 connected to the shutter 53 is pulled into the container main body 51 from the toner supply port 51 a and accommodated along the inner peripheral surface of the container main body 51 . In this state, the developing device 4 can be used by rotating the developing roller 43 clockwise and rotating the stirring paddle 47 counterclockwise.

FIG. 8 is a diagram showing a state in which the toner in the developing device 4 has been emptied. When it is detected that the toner in the developing device 4 is empty (toner empty state), a display prompting replacement of the toner container 5 is displayed on the liquid crystal display section 81, and the toner container 5 is replaced. At this time, if the toner container 5 is removed while the toner supply port 51a is open, the toner remaining inside the toner container 5 falls from the toner supply port 51a and contaminates the inside and the periphery of the image forming apparatus 100. There is a risk of

Therefore, as shown in FIG. 8, before removing the toner container 5, the operation lever 53a is moved from the engaging portion 57b to the initial position (position shown in FIG. 3), thereby moving the shutter 53 to a position overlapping the toner supply port 51a. (closed position). As a method for detecting the toner empty state of the developing device 4, the toner consumption amount is calculated based on the cumulative printing rate ΣP in the calculation unit 97, and the calculated toner consumption amount is used as the toner replenishment amount supplied to the developing device 4. When the remaining amount of toner, which is subtracted from the initial value of , becomes 0, the toner empty state is detected.

According to this embodiment, when replenishing the toner from the toner container 5 to the developing device 4, the toner in the toner container 5 is replenished all at once after the toner in the developing device 4 is used up. Therefore, the toner remaining in the developing device 4 and the new toner in the toner container 5 do not cause charging failure due to the difference in condition between the toner and the new toner in the toner container 5, and the fogging phenomenon can be suppressed.

Further, the scattering path of the toner in the developer container 41 can be shielded by the shielding sheet 55 that hangs down from the toner container 5 into the developing device 4 when the toner is replenished. Therefore, scattering of toner to the outside of the developing device 4 can be suppressed. Furthermore, since the shielding sheet 55 is stored in the toner container 5 by moving the shutter 53 from the open position during the printing operation, there is no fear of interfering with the printing operation.

FIG. 9 is a side sectional view schematically showing the developing device 4 and the toner container 5 mounted on the image forming apparatus 100 according to the second embodiment of the invention. FIG. 10 is a view of the rear side (back side of the paper surface of FIG. 9) of the developing device 4 and the toner container 5 shown in FIG. In this embodiment, the shielding sheet 55 and the connecting member 60 are provided inside the developing device 4 . The connecting member 60 connects the shutter 53 and the shielding sheet 55 when the toner container 5 is mounted on the container mounting portion 41a of the developer container.

Further, in the toner container 5, the operation lever 53a is provided substantially at the center of the shutter 53 in the circumferential direction, and the guide groove 51b of the container body 51 is formed in an arc shape. Other configurations of the developing device 4 and the toner container 5 are the same as those of the first embodiment.

A procedure for supplying toner from the toner container 5 to the developing device 4 in the image forming apparatus 100 of the second embodiment will be described with reference to FIGS. 9 and 10 and FIGS. 11 to 14 described later. FIG. 9 shows the state immediately after the body cover (not shown) of the image forming apparatus 100 is opened and the toner container 5 is replaced with a new one. In this state, the shutter 53 is arranged at the closed position for closing the toner supply port 51a. The shielding sheet 55 is arranged along the bottom surface of the developer container 41 .

As shown in FIG. 10, the operating lever 53a protrudes to the back side of the toner container 5, and when the toner container 5 is attached to the container attachment portion 41a, the operating lever 53a is connected to the developing device 4 on the back side. It engages the upper end of member 60 . Also, the lower end of the connecting member 60 is connected to the shielding sheet 55 . As a result, the connecting member 60 and the shielding sheet 55 are moved in conjunction with the opening/closing operation of the shutter 53 while the toner container 5 is attached to the container attachment portion 41a.

FIG. 11 shows a state in which the shutter of the toner container 5 is opened from the state shown in FIG. FIG. 12 is a diagram of the rear side of the developing device 4 and the toner container 5 shown in FIG. After the toner container 5 is attached to the container attachment portion 41a of the developing device 4, as shown in FIG. 11, the operation lever 53a is moved counterclockwise to the other end of the guide groove 51b, thereby closing the shutter 53. , to the open position where the toner supply port 51a is opened.

As a result, the connecting member 60 moves upward as the shutter 53 moves, and the shielding sheet 55 connected to the connecting member 60 rises from the bottom surface of the developer container 41 . The shielding sheet 55 allows the inside of the developer container 41 to be separated from the first region R1 on the side of the developer container 41 near the photosensitive drum 1 (the side on which the developing roller 43 and the regulating blade 45 are arranged) and the photosensitive drum 1. It is divided into a second region R2 on the far side (container mounting portion 41a side). Further, the toner replenishing port 51a is opened and the entire amount of the toner T in the toner container 5 is replenished to the second area R2 in the developing container 41 at once. As a result, scattering of toner from the gap between the developing container 41 and the developing roller 43 or the regulating blade 45 can be suppressed.

FIG. 13 is a side sectional view schematically showing the developing device 4 and the toner container 5 during printing operation. In the state of FIG. 11, the inside of the developing container 41 is divided into the first region R1 and the second region R2 by the shielding sheet 55, so that the toner T supplied to the second region R2 is transferred to the developing roller in the first region R1. 43, and the developing device 4 cannot be used. Therefore, as shown in FIG. 13, the operation lever 53a is moved clockwise and returned to the initial position (see FIG. 9), thereby moving the shutter 53 to the closed position.

As a result, the connecting member 60 moves downward along with the movement of the shutter 53 , so that the shielding sheet 55 is accommodated again along the bottom surface of the developing container 41 . In this state, the developing device 4 can be used by rotating the developing roller 43 clockwise and rotating the stirring paddle 47 counterclockwise.

FIG. 14 is a diagram showing a state in which the developing device 4 is empty of toner. When it is detected that the toner in the developing device 4 is empty (toner empty state), a display prompting replacement of the toner container 5 is displayed on the liquid crystal display section 81, and the toner container 5 is replaced. The method of detecting the toner empty state of the developing device 4 is the same as in the first embodiment. At this time, since the toner supply port 51a is closed by the shutter 53 as shown in FIG. There is no possibility that the inside and the periphery of the image forming apparatus 100 will be contaminated by falling.

According to the present embodiment, as in the first embodiment, when replenishing toner from the toner container 5 to the developing device 4, after the toner in the developing device 4 is used up, the entire amount of toner in the toner container 5 is replenished at once. do. Therefore, the toner remaining in the developing device 4 and the new toner in the toner container 5 do not cause charging failure due to the difference in condition between the toner and the new toner in the toner container 5, and the fogging phenomenon can be suppressed.

Further, the scattering path of the toner in the developer container 41 can be shielded by the shielding sheet 55 rising from the bottom surface of the developing device 4 as the shutter 53 moves during toner replenishment. Therefore, as in the first embodiment, scattering of toner to the outside of the developing device 4 can be suppressed. Furthermore, since the shielding sheet 55 is retracted along the bottom surface of the developer container 41 by moving the shutter 53 to the closed position during the printing operation, there is no fear of hindering the printing operation.

In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the configuration using the developing device 4 using the magnetic one-component developer as shown in FIG. 2 has been described, but the present invention is not limited to this, and the non-magnetic one-component developer consisting only of non-magnetic toner is used. It may be a developing device 4 that uses a developer.

Further, in each of the above-described embodiments, the toner consumption amount is calculated based on the cumulative print rate ΣP, and the toner remaining amount obtained by subtracting the calculated toner consumption amount from the initial value of the toner replenishment amount replenished in the developing device 4 is calculated. Although the toner empty state of the developing device 4 is detected, the developing device 4 may be provided with a toner detection sensor for detecting the remaining amount of toner. In the case of a magnetic one-component developer, a magnetic permeability sensor can be used as the toner detection sensor. In the case of a non-magnetic one-component developer, a piezoelectric sensor or a PI (photo interrupter) sensor can be used as the toner detection sensor.

In addition, the present invention is not limited to the monochrome printer as shown in FIG. It can be applied to various image forming apparatuses equipped with an agent container.

INDUSTRIAL APPLICABILITY The present invention is applicable to an image forming apparatus having a detachable developer storage container for supplying developer to a developing device. By using the present invention, it is possible to provide an image forming apparatus capable of suppressing developer leakage when a large amount of developer is replenished from a developer container at once.

1 photoreceptor drum 4 developing device 5 toner container (developer container)
41 developer container 41a container mounting portion 43 developer roller (developer carrier)
45 Regulation blade 47 Stirring paddle 51 Container main body (container main body)
51a toner supply port (developer supply port)
51b guide groove 53 shutter 53a operation lever 55 shielding sheet 57a, 57b engagement portion 60 connecting member 90 control portion 97 calculation portion (developer amount detection portion)
100 image forming apparatus R1 first area R2 second area

Claims (7)

an image carrier on which an electrostatic latent image is formed;
a developing container storing a one-component developer consisting of only toner to be supplied to the image carrier;
a developer carrier that is rotatably supported by the developer container so as to face the image carrier and that carries the developer;
a developing device for developing the electrostatic latent image formed on the image carrier into a toner image;
a cylindrical container body containing the developer to be replenished to the developing device and having a developer replenishing port formed on an outer peripheral surface thereof for discharging the developer;
It is mounted movably in the circumferential direction along the inner peripheral surface of the container body, and moves to a plurality of positions including an open position for opening the developer supply port and a closed position for closing the developer supply port. possible shutter and
a developer storage container that is detachable from the developing device;
In an image forming apparatus comprising
Along with the movement of the shutter, a shielding position that divides the inside of the developing container into a first area close to the image carrier and a second area far from the image carrier, and a retraction position retracted from the shielding position. Equipped with selectively arranged shielding sheets,
By moving the shutter to the open position to open the developer supply port, the shielding sheet is arranged at the shielding position, and the entire amount of the developer contained in the container main body is released to the developer supply port. refilling the second region of the container at once;
An image forming apparatus, wherein the shielding sheet moves from the shielding position to the retracted position by moving the shutter from the open position. The shielding sheet is connected to an upstream end of the shutter in the moving direction,
By moving the shutter from the closed position to the open position, the shielding sheet is pressed by the developer passing through the developer supply port and arranged at the shielding position,
2. The shielding sheet is drawn into the container main body and placed at the retracted position by moving the shutter from the open position to the collection position on the downstream side in the moving direction. image forming device. The shielding sheet is arranged in the developer container, and includes a connecting member that connects the shutter and the shielding sheet when the developer container is attached,
By moving the shutter from the closed position to the open position, the shielding sheet is arranged at the shielding position by the connecting member,
2. The method according to claim 1, wherein the shielding sheet is arranged at the retracted position along the bottom surface of the developer container by the connecting member by moving the shutter from the open position to the closed position. Image forming device. The shutter has an operation lever that protrudes outside through an arc-shaped guide groove formed in the end surface of the container body,
4. The shutter is moved to a plurality of positions including the open position and the closed position by moving the operating lever along the guide groove. The described image forming apparatus. 5. The image forming apparatus according to claim 4, wherein the guide groove has an engaging portion with which the operation lever is engaged when the shutter is at a predetermined position including the open position and the closed position. . a developer amount detection unit that detects the amount of the developer stored in the developing device;
a display unit for displaying that the developer in the developing device is empty based on the detection result of the developer amount detection mechanism;
6. The image forming apparatus according to claim 1, further comprising: The developer amount detection unit calculates a developer consumption amount based on a cumulative printing rate obtained by accumulating a printing rate for each image, and transfers the calculated developer consumption amount from the developer storage container to the developing apparatus. 7. The image forming apparatus according to claim 6, wherein the developer amount is detected by subtracting it from an initial value of the developer replenishment amount replenished in the apparatus.

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