JP2006011214A - Development device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a development device capable of storing spare toner inside the device, using a simple constitution. <P>SOLUTION: The development device 40 includes a first toner storage chamber 64 and a magnet storage chamber 68, separated from the first storage chamber 64 by a partition wall 66. A magnet support 72 is disposed in the magnet storage chamber 68. The magnet support 72 has a body 74 whose shape is, for example, cylindrical, and a support shaft 76 disposed in the center of the body 74 and supported by a cartridge case 62 so as to freely rotate. In addition, a magnet 78 is disposed in the circumferential edge of the body 74 of the magnet support 72. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a developing device provided with a preliminary toner accommodating mechanism and an image forming apparatus having the developing device.

  As this type of developing device, there is known a developing device having a detachable toner cartridge separately from the developing portion, and having two large and small tanks having different toner storage amounts in the toner cartridge. For example, Patent Document 1 discloses that switching is performed so that toner is supplied from a small tank as soon as the toner in the large tank runs out. Further, it is disclosed that there is a display unit for displaying that the small tank has been switched and a unit for prohibiting printing when the toner in the small tank runs out.

Japanese Patent Laid-Open No. 11-65250

  However, in the conventional developing device, since the inside of the toner cartridge is divided into two chambers, it is necessary to fill the toner twice, which increases the number of steps. Further, since the toner supply switching and conveying mechanism is complicated, the cost may increase.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing device that can store spare toner in the apparatus with a simple configuration.

  In order to achieve the above object, the first feature of the present invention is that a toner storage chamber in which toner is stored and a part of the toner stored in the toner storage chamber are used as spare toner in the toner storage chamber. The developing device includes a holding unit for holding, and a releasing unit for releasing the holding of the preliminary toner by the holding unit.

  Preferably, the toner accommodated in the toner accommodating chamber has magnetism, and the holding means is composed of a magnet.

  Preferably, the magnet is housed in a magnet housing chamber separated from the toner housing chamber by a partition wall.

  Preferably, the magnet is an electromagnetic magnet.

  Furthermore, it preferably further includes a detecting means for detecting the remaining amount of toner in the toner containing chamber.

  Furthermore, the present invention includes an image forming apparatus having a developing device having the above-described characteristics.

  The second feature of the present invention is that a toner storage chamber that stores toner, and a holding unit that holds a part of the toner stored in the toner storage chamber as a spare toner in the toner storage chamber. A developing device having a releasing means for releasing the holding of the preliminary toner by the holding means, a detecting means for detecting the remaining amount of toner in the toner storage chamber, and the holding means according to a detection result detected by the detecting means. And an image forming apparatus having control means for controlling the releasing means.

  According to the present invention, it is possible to store spare toner in the developing device with a simple configuration.

Next, a first embodiment of the present invention will be described.
FIG. 1 shows a side surface of an image forming apparatus 10 according to the first embodiment of the present invention. The image forming apparatus 10 according to the present exemplary embodiment includes an image forming apparatus main body 12, and includes, for example, a one-stage sheet feeding tray 14 below the image forming apparatus main body 12. Further, the image forming apparatus 10 includes a paper discharge tray 16 formed integrally with the upper surface of the image forming apparatus main body 12. A feed roll 18 that supplies recording paper from the paper feed tray 14 and a retard roll 20 that sprinkles the supplied paper one by one are arranged at the upper part near the rear end of the paper feed tray 14.

  The paper transport path 22 is a paper path from the feed roll 18 to the discharge roll 24, and this paper transport path 22 is in the vicinity of the back surface (right side surface in FIG. 1) of the image forming apparatus main body 12. To a heating roll 26 and a pressure roll 28 which will be described later. A transfer roll 30, which will be described later, is disposed on the upstream side of the heating roll 26 and the pressure roll 28 in the paper conveyance path 22, and a registration roll 32 is disposed on the upstream side of the transfer roll 30.

  Accordingly, the recording paper fed from the paper feed tray 14 by the feed roll 18 is rolled by the retard roll 20 and only the uppermost recording paper is guided to the paper transport path 22 and is temporarily stopped by the registration roll 32 to take timing. Then, a toner image is transferred between a photoconductor 34 and a transfer roll 30, which will be described later, and the transferred toner image is fixed by a heating roll 26 and a pressure roll 28, and an image is formed from a discharge port by a discharge roll 24. The paper is discharged to a paper discharge tray 16 provided at the top of the apparatus main body 12. The paper discharge tray 16 has a low discharge port portion (near the discharge roll 24) and is inclined so as to gradually increase toward the front surface direction (left direction in FIG. 1).

  In the image forming apparatus main body 12, for example, a process cartridge 36 (exchange unit) is detachably provided at a substantially central portion. The process cartridge 36 includes a photosensitive member 34, a charging roll 38 that uniformly charges the photosensitive member 34, a toner cartridge 42 that contains magnetic toner, and a development that develops the electrostatic latent image formed on the photosensitive member 34 with magnetic toner. A developing device 40 having an apparatus main body 44 is integrated. Further, the process cartridge 36 has a cleaning blade 52 that scrapes the magnetic toner remaining on the photosensitive member 34 upstream of the charging roller 38 in the rotation direction of the photosensitive member 34 and a toner recovery bottle that collects the scraped magnetic toner. 54 is disposed.

  Above the process cartridge 36, an exposure device 46 for writing a latent image on the charged photosensitive member 34 with a laser beam is arranged. The exposure device 46 is provided with a laser emitter 48 that blinks laser light according to input image data, and a folding mirror 50 that guides the laser light emitted from the laser emitter 48 in the direction of the photosensitive member 34. Has been.

  A small cover 58 that is rotatably supported by the image forming apparatus main body 12 by a small cover hinge 56 is provided on the front surface of the image forming apparatus main body 12. In addition, an opening / closing cover 60 is provided that can freely open and close the area opened and closed by the small cover 58. The user can replace the replacement unit and perform jam processing by opening the open / close cover 60 and the small cover 58 together to ensure a large opening on the front surface of the image forming apparatus main body 12.

  A transfer roll 30 is opposed to the photosensitive member 34 of the process cartridge 36 with the paper transport path 22 interposed therebetween. That is, the transfer position of the toner image is between the transfer roll 30 and the photoconductor 34, and the transfer roll 30 transfers the toner image formed on the photoconductor 34 to the recording paper at this transfer position.

  Above the transfer position, fixing means comprising a heating roll 26 and a pressure roll 28 is disposed. The heating roll 26 and the pressure roll 28 fix the toner image transferred onto the recording paper by the transfer roll 30 and convey it toward the discharge roll 24.

2 and 3, details of the developing device 40 are shown. 2 is a cross-sectional view of the developing device 40, and FIG. 3 is an enlarged cross-sectional view of a portion A in FIG.
The developing device 40 includes a developing device main body 44 and a toner cartridge 42 that is detachably attached to the developing device main body 44.
The toner cartridge 42 includes a first toner storage chamber 64 that is surrounded by a cartridge case 62 and a magnet 66 that is separated from the first toner storage chamber 64 by a partition 66 that is formed integrally with the cartridge case 62. Chamber 68. The first toner storage chamber 64 stores magnetic toner, and is provided with a first stirring / conveying member 70 for stirring and transporting the magnetic toner. The first stirring / conveying member 70 is rotated in the first toner storage chamber 64 by receiving a driving force from a driving source (not shown), for example.

  A magnet support portion 72 is provided in the magnet storage chamber 68. The magnet support portion 72 includes, for example, a cylindrical main body portion 74 and a support shaft 76 provided at the center of the main body portion 74, and the support shaft 76 is supported so as to be rotatable on the cartridge case 62. Has been. Further, a magnet 78 is provided on the circular edge of the main body 74 of the magnet support 72. The magnet 78 constitutes a holding unit that holds a part of the magnetic toner stored in the first toner storage chamber 64 as a spare toner. The magnet support portion 72 rotates about the support shaft 76 in the direction of the arrow in FIG.

  The magnet housing chamber 68 is provided with a recess 80 for rotating the magnet support portion 72. By operating, for example, the main body 74 of the magnet support 72 via the recess 80, the magnet support 72 can be rotated, and the preliminary toner can be held or released.

  A toner supply path 82 is formed at the left and right ends of the first toner storage chamber 64 so as to protrude downward. The toner supply path 82 communicates with a second toner storage chamber 84 provided in the developing device main body 44, and the magnetic toner conveyed by the first agitating / conveying member 70 passes through the toner supply path 82. The second toner storage chamber 84 is supplied.

The developing device main body 44 includes a second toner storage chamber 84, a second stirring transport member 86 that stirs and transports the magnetic toner supplied to the second toner storage chamber 84, and the second stirring transport member 86. A third agitating and conveying member 88 for agitating and conveying the toner to be conveyed, a developing roller 90 that faces the photosensitive member 34 and supplies magnetic toner to the photosensitive member 34, and a magnetic toner adhering to the surface of the developing roller 90 And a layer thickness regulating member 92 that regulates the layer thickness. The second agitating / conveying member 86 and the third agitating / conveying member 88 are configured to rotate within the second toner storage chamber 84 by receiving a driving force from a driving source (not shown), for example. As is well known, the developing roll 90 is obtained by winding a sleeve around a magnet roll. The layer thickness regulating member 92 is made of, for example, resin and is provided so as to contact the developing roll 90.
Further, the developing device 40 is provided with a later-described toner remaining amount sensor 94 that constitutes a detecting unit that detects the remaining amount of toner in the first toner storage chamber 64.

FIG. 4 shows display means for displaying the remaining amount of toner detected by the detection means.
The remaining toner sensor 94 causes an electrical change when the remaining amount of toner in the first toner storage chamber 64 reaches a predetermined value. The toner remaining amount detection unit 96 detects an electrical change by the toner remaining amount sensor 94 and outputs a toner empty signal indicating that the remaining amount of toner in the first toner storage chamber 64 is less than a predetermined value. Output for. The control unit 98 displays, for example, on the display device 100 provided on the upper surface of the image forming apparatus main body 12 that the remaining amount of toner in the first toner storage chamber 64 is less than a predetermined value.

Next, the operation of the above embodiment will be described.
Sufficient magnetic toner is stored in the first toner storage chamber 64 of the developing device 40, and as shown in FIG. 3A, the magnet 78 is in a position near the partition wall 66 (hereinafter referred to as a close state). Therefore, the magnet 78 attracts a part of the magnetic toner stored in the first toner storage chamber 64 by a magnetic force and holds it as a spare toner. The magnetic toner that is stored in the first toner storage chamber 64 and is not held as spare toner is supplied to the second toner storage chamber 84 via the toner supply path 82 and is conveyed toward the developing roll 90.

  When the image forming signal is sent, the photosensitive member 34 is uniformly charged by the charging roll 38, and light is emitted from the exposure device 46 to the charged photosensitive member 34 based on the image signal. The light beam from the exposure device 46 exposes the surface of the photoconductor 34 to form a latent image. The latent image of the photoreceptor 34 formed by the exposure device 46 is developed with magnetic toner by the developing roll 90.

  On the other hand, the recording paper stored in the paper feed tray 14 by the paper feed signal or the like is sent out by the feed roll 18, is turned by the retard roll 20, is guided to the paper transport path 22, and is temporarily stopped by the registration roll 32, It is guided between the photoconductor 34 and the transfer roll 30 with timing. When the recording sheet is guided between the photoreceptor 34 and the transfer roll 30, the toner image formed on the surface of the photoreceptor 34 is transferred to the recording sheet by the transfer roll 30. After the transfer, residual toner remaining on the photoreceptor 34 is scraped off and collected by the cleaning blade 52.

  The recording paper to which the toner image has been transferred is guided between the heating roll 26 and the pressure roll 28, and the toner image is fixed by thermal pressure. The recording sheet on which the toner image is fixed is discharged from the discharge port to the discharge tray 16 by the discharge roll 24.

  In this way, the amount of magnetic toner in the first toner storage chamber 64 is reduced. When the toner remaining amount in the first toner storage chamber 64 reaches a predetermined value, the toner remaining amount sensor 94 causes an electrical change. This electrical change is detected by the toner remaining amount detecting unit 96, and a toner empty signal is output from the toner remaining amount detecting unit 96 to the control unit 98. When the control unit 98 inputs a toner empty signal, the display device 100 displays that the toner amount in the toner cartridge 42 is small.

  When the magnet support 72 is rotated through the recess 80 provided in the magnet housing chamber 68, the magnet 78 moves to a position away from the partition wall 66 (hereinafter referred to as a non-proximity state) as shown in FIG. Is done. In this state, the magnet 78 cannot adsorb the magnetic toner accommodated in the first toner accommodating chamber 64, and the spare toner adsorbed by the magnet 78 is placed on the bottom of the first toner accommodating chamber 64. Will fall. In this way, the holding of the spare toner is released.

  The magnetic toner that has been released from the holding state and is dropped is agitated and conveyed by the first agitating and conveying member 70, and is supplied from the first toner accommodating chamber 64 to the second toner accommodating chamber 84 via the toner supply path 82. Further, the toner remaining amount sensor 94 causes an electrical change again due to the released magnetic toner, and the toner remaining amount detecting unit 96 indicates that the amount of remaining toner in the first toner storage chamber 64 is greater than a predetermined value. Detect and output a signal to that effect to the control unit 98. The fact that the amount of remaining toner in the first toner storage chamber 64 is less than a predetermined value is displayed on the display device 100 by the control unit 98.

In this way, the spare toner is held in the first toner storage chamber 64 provided in the developing device 40, and when the remaining amount of toner in the first toner storage chamber 64 reaches a predetermined value, the spare toner is stored. Is released, the image forming apparatus 10 can print even after displaying a warning.
Further, since the toner is filled into the first toner storage chamber 64 only once at one place, the processing man-hours and costs can be reduced. Further, since the magnetic toner and the spare toner to be supplied to the developing device main body 44 are accommodated in the same toner accommodating chamber, no toner leakage or the like occurs even when the driven gear 102 of the spare toner is started.
When the toner empty signal is input, the control unit 98 may control the image forming apparatus 10 to stop the printing operation after printing a predetermined number of sheets after inputting the toner empty signal.

Next, an image forming apparatus 10 according to the second exemplary embodiment of the present invention will be described.
In FIG. 5, a control means for controlling the magnet support 72 is shown. In FIG. 5, the same reference numerals are assigned to substantially the same control means as shown in FIG.
In the first embodiment, the magnet support 72 is manually rotated through the recess 80, but in the second embodiment, the magnet support 72 is automatically rotated under the control of the control unit 98.

  A driven gear 102 is provided at one end of the magnet support portion 72, and a drive gear 104 is engaged with the driven gear 102, and the drive gear 104 is connected to the motor 106. The control unit 98 controls the drive of the motor 106 based on the information detected by the toner remaining amount detection unit 96, rotates the magnet support unit 72 via the drive gear 104, and controls the position of the magnet 78.

Therefore, when the magnetic toner is consumed, the magnetic toner in the first toner storage chamber 64 is reduced, and the remaining amount of toner in the first toner storage chamber 64 reaches a predetermined value, the toner remaining amount sensor 94 is electrically changed. Produce. This electrical change is detected by the toner remaining amount detecting unit 96, and a toner empty signal is output from the toner remaining amount detecting unit 96 to the control unit 98. When the control unit 98 inputs a toner empty signal, the magnet support unit 72 is automatically rotated via the drive gear 104 by the motor 106 controlled by the control unit 98. At this time, the magnet 78 provided on the magnet support portion 72 is moved from the close position to the non-close position. When the magnet 78 is moved to the non-adjacent position, the spare toner that has been held so far by the magnetic force of the magnet 78 is released and falls to the bottom of the first toner storage chamber 64. The released magnetic toner is agitated and conveyed by the first agitating and conveying member 70 and supplied from the first toner accommodating chamber 64 to the second toner accommodating chamber 84 via the toner supply path 82.
In this way, the spare toner is held in the first toner storage chamber 64 provided in the developing device 40, and when the remaining amount of toner in the first toner storage chamber 64 reaches a predetermined value, the spare toner is stored. Can be automatically released.

Next, a modification of the image forming apparatus 10 according to the second embodiment of the present invention will be described.
In FIG. 6, the holding of the spare toner and a control circuit for releasing the holding are shown. In FIG. 6, the same reference numerals are given to substantially the same control means as shown in FIG.
In the second embodiment, the holding of the preliminary toner and the release of the held toner are controlled by rotating the magnet support 72 by the motor 106. In the present modification, the magnet support 72 is provided on the magnet support 72. The magnet is an electromagnetic magnet 110, and by controlling the current flowing through the electromagnetic magnet 110, the holding of the spare toner and the release of the held toner are controlled.

  The control circuit includes a toner remaining amount detection unit 96 that detects an electrical change of the toner remaining amount sensor 94, and an electrical change that occurs when the circuit is closed by the toner remaining amount detection unit 96, for example, a transistor 108. And an electromagnetic magnet 110 for holding spare toner. The toner remaining amount detection unit 96 serves as a switch in this control circuit. The transistor 108 changes the current flowing through the electromagnetic magnet 110 when detecting an electrical change on the emitter side. The electromagnetic magnet 110, for example, attracts the magnetic toner in the first toner storage chamber 64 and holds it as a spare toner when current is flowing, and releases the holding of the spare toner when no current flows. To do.

  Accordingly, when the amount of toner in the first toner storage chamber 64 falls below a predetermined value, the toner remaining amount sensor 94 undergoes an electrical change, the toner remaining amount detecting unit 96 opens the control circuit switch, and the transistor 108 The current flowing through the electromagnetic magnet 110 is stopped. The reserve toner that has been attracted and held until now by the magnetic force of the electromagnetic magnet 110 is released and falls to the bottom of the first toner storage chamber 64, and the released magnetic toner is stored in the first toner storage. The toner is supplied from the chamber 64 to the second toner storage chamber 84 via the toner supply path 82.

As described above, also in the present modification, the reserve toner is held in the first toner storage chamber 64 provided in the developing device 40, and the remaining amount of toner in the first toner storage chamber 64 becomes a predetermined value. In this case, it is possible to release the holding of the spare toner.
Note that a warning displayed on the display device 100 when the toner remaining amount reaches a predetermined value is confirmed, and an external terminal device such as a PC (not shown) connected to the image forming apparatus 10 is operated via a network, for example. Thus, the current flowing through the electromagnetic magnet 110 may be stopped.

Next, a third embodiment of the present invention will be described.
FIG. 7 shows a cross-sectional view of a developing device 40 according to the third embodiment of the present invention. In FIG. 7, the same reference numerals are assigned to substantially the same components as those of the developing device 40 shown in FIG.
In the first embodiment, a part of the magnetic toner accommodated in the first toner accommodating chamber 64 of the developing device 40 is retained in the first toner accommodating chamber 64 as a spare toner. In the embodiment, a part of the magnetic toner stored in the second toner storage chamber 84 of the developing device 40 is held in the second toner storage chamber 84 as a spare toner. In addition, the remaining toner sensor 94 constitutes a detection unit that detects the remaining amount of toner in the second toner storage chamber 84.

  The developing device 40 includes a developing device main body 44 and a toner cartridge 42 that is detachably attached to the developing device main body 44. The toner cartridge 42 has a first toner storage chamber 64. The first toner storage chamber 64 stores magnetic toner, and is provided with a first stirring / conveying member 70 for stirring and transporting the magnetic toner. Yes.

The developing device main body 44 includes a second toner storage chamber 84, a magnet storage chamber 68 separated from the second toner storage chamber 84 by a partition wall 66, and a magnet support portion 72 provided in the magnet storage chamber 68. A second agitating and conveying member 86 for agitating and conveying the magnetic toner; a third agitating and conveying member 88 for agitating and conveying the toner conveyed by the second agitating and conveying member 86; and supplying the magnetic toner to the photosensitive member 34. And a layer thickness regulating member 92 that regulates the layer thickness of the magnetic toner attached to the surface of the developing roll 90. The remaining toner sensor 94 is disposed in the developing device main body 44 of the developing device 40.
As shown in FIG. 5, the magnet support portion 72 is provided with a magnet 78 that constitutes a holding unit that holds the preliminary toner. The magnet support part 72 is rotated by being controlled by the control part 96.

  Accordingly, when the magnetic toner is consumed, the magnetic toner in the second toner storage chamber 84 is reduced, and the remaining amount of toner in the second toner storage chamber 84 reaches a predetermined value, the toner remaining amount sensor 94 is electrically changed. Produce. This electrical change is detected by the toner remaining amount detecting unit 96, and a toner empty signal is output from the toner remaining amount detecting unit 96 to the control unit 98. When the control unit 98 inputs a toner empty signal, the display device 100 displays that the amount of toner in the developing device 40 is small. Further, when the magnet support portion 72 is rotated and the magnet 78 is moved from the proximity position to the non-proximity position, the reserve toner that has been held so far by the magnetic force of the magnet 78 is released and the first toner is released. 2 falls to the bottom of the toner storage chamber 84. The magnetic toner that has fallen after being released is conveyed in the direction of the developing roll 90 by the second agitating and conveying member 86 and the third agitating and conveying member 88.

In this way, when the spare toner is held in the second toner storage chamber 84 provided in the developing device 40 and the remaining amount of toner in the second toner storage chamber 84 reaches a predetermined value, the reserve toner is stored. Can be released.
The toner cartridge 42 and the developing device main body 44 do not have to be detachable, and may be configured integrally.
Moreover, the magnet support part 72 is not restricted to what is rotated automatically, You may rotate manually as FIG. 3 shows. Further, the magnet provided in the magnet support portion 72 may be an electromagnetic magnet 110 as shown in FIG. 6, and when a current flows through the electromagnetic magnet 110, the electromagnetic magnet 110 is in the second toner storage chamber 84. When the magnetic toner is adsorbed and held as a spare toner and no current flows, the holding of the spare toner may be released.

1 is a side view of an image forming apparatus 10 according to a first embodiment of the present invention. 1 is a cross-sectional view of a developing device 40 according to a first embodiment of the present invention. FIGS. 3A and 3B are enlarged cross-sectional views of a portion A in FIG. 2, in which FIG. 2A is a diagram illustrating that the magnet 78 is in proximity to the partition wall 66, and FIG. It is a figure which illustrates being in a proximity state. FIG. 4 is a diagram illustrating a display unit that displays a toner remaining amount detected by a detection unit. 7 is a diagram illustrating a control device for controlling rotation of a magnet support portion 72 in the image forming apparatus 10 according to the second embodiment of the present invention. FIG. FIG. 10 is a diagram exemplifying holding of preliminary toner by an electromagnetic magnet and a control circuit for releasing this holding in a modification of the image forming apparatus 10 according to the second exemplary embodiment of the present invention. It is sectional drawing of the developing device 40 which concerns on the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 34 Photoconductor 36 Process cartridge 38 Charging roll 40 Developing apparatus 42 Toner cartridge 44 Developing apparatus main body 62 Cartridge case 64 First toner storage chamber 66 Separator 68 Magnet storage chamber 70 First stirring and conveying Member 72 Magnet support portion 74 Main body portion 76 Support shaft 78 Magnet 80 Recess 82 Toner supply path 84 Second toner storage chamber 86 Second agitating and conveying member 88 Third agitating and conveying member 90 Developing roller 94 Toner remaining amount sensor 96 Toner Remaining amount detection unit 98 Control unit 100 Display device 102 Driven gear 104 Drive gear 106 Motor 108 Transistor 110 Electromagnetic magnet

Claims (7)

A toner storage chamber for storing toner;
Holding means for holding a part of the toner stored in the toner storage chamber as a spare toner in the toner storage chamber;
Release means for releasing the holding of the preliminary toner by the holding means;
A developing device. The toner stored in the toner storage chamber has magnetism,
The developing device according to claim 1, wherein the holding unit includes a magnet. The developing device according to claim 2, wherein the magnet is housed in a magnet housing chamber separated from the toner housing chamber by a partition wall. The developing device according to claim 2, wherein the magnet is an electromagnetic magnet. The developing device according to claim 1, further comprising a detection unit configured to detect a remaining amount of toner in the toner storage chamber. An image forming apparatus comprising the developing device according to claim 1. A toner storage chamber for storing toner, a holding unit for holding a part of the toner stored in the toner storage chamber in the toner storage chamber as a backup toner, and a release unit for releasing the holding of the backup toner by the holding unit And a developing unit that detects the remaining amount of toner in the toner storage chamber;
Control means for controlling the holding means and the releasing means according to the detection result detected by the detection means;
An image forming apparatus.

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