JP4872936B2 - Image forming apparatus and developing cartridge - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus and a developing cartridge equipped in the image forming apparatus.

For example, as an electrophotographic image forming apparatus, the laser printer described in Patent Document 1 is equipped with a drum cartridge and a developing cartridge.
The drum cartridge includes a photosensitive drum on which an electrostatic latent image is formed. The developing cartridge includes, in its housing, a toner hopper, a developing roller that is driven to rotate, a supply roller, and an agitator. The toner hopper is filled with toner. The toner is agitated by a rotating agitator, supplied to the supply roller, and then supplied to the photosensitive drum via the developing roller. Thereby, the electrostatic latent image on the photosensitive drum is visualized.

Here, an input gear that receives a driving force from the motor of the image forming apparatus main body, an agitator gear that is coupled to the rotating shaft of the agitator, and an idle gear that meshes with these gears are provided on the side surface of the housing of the developing cartridge. It has been. The driving force received by the input gear from the motor of the image forming apparatus main body is transmitted to the agitator gear by the idle gear.
JP 2006-208941 A

  There are a plurality of developing cartridge models depending on the model of the image forming apparatus. Therefore, in order to reduce the manufacturing cost of the developing cartridge, it is desirable that a rotating body such as a gear can be used in common in a plurality of types of developing cartridges. However, since the shape of the developing cartridge differs depending on the model, it is difficult to use a rotating body in common among a plurality of types of developing cartridges.

  For example, when the driving force is transmitted from the input gear to the agitator gear via the idle gear as in the developing cartridge described in Patent Document 1, the shaft distance between the input gear and the agitator gear depends on the model of the developing cartridge. If the distance changes, the shapes of the input gear and the agitator gear must be changed. Therefore, it is difficult to use the input gear and the agitator gear of the developing cartridge described in Patent Document 1 with other types of developing cartridges.

  An object of the present invention is to provide a developing cartridge that can use a rotating member in common among developing cartridges of other models, and an image forming apparatus equipped with the developing cartridge.

In order to achieve the above object, the invention according to claim 1 is provided with a housing provided with a developer containing portion for containing a developer, and the housing provided with the housing to transmit a driving force. A stirring member that stirs the developer in the developer container, a first rotating body that is rotatably supported by the casing and to which a driving force is transmitted, and a rotating member that is rotatably supported by the casing. An endless shape that transmits driving force from the first rotating body to the second rotating body by being wound between the connected second rotating body and the first rotating body and the second rotating body. And a developing roller that carries the developer and rotates when the driving force is transmitted from the first rotating body, and a third roller rotatably supported by the housing and connected to the developing roller. The developer is supplied to the gear and the developing roller, and the driving force is transmitted from the first rotating body. And a fourth gear rotatably supported by the casing and connected to the supply roller. The first rotating body is wound around which the transmission body is wound. A rotating portion, and a meshing portion that is disposed away from the winding portion and meshes with the third gear and the fourth gear, and the housing includes the first rotating body, the second rotating body, and A side wall on which the transmission body is disposed, and a projecting member provided in a region surrounded by the first rotary body, the second rotary body, and the transmission body on the side wall, and protruding toward the outside of the housing The projecting member includes a reflecting member that reflects detection light for detecting the amount of developer in the developer accommodating portion, and a passage path through which the detection light reflected by the reflecting member passes. It is characterized by.

Further, the invention according to billed claim 2 is the invention according to claim 1, wherein the housing, the first rotary member, a side wall and the second rotary body and the transfer body is disposed, said side wall And a window that is provided in a region surrounded by the first rotating body, the second rotating body, and the transmission body and that allows detection light for detecting the amount of developer in the developer accommodating portion to pass therethrough. It is characterized by being.

According to a third aspect of the present invention, there is provided a housing provided with a developer containing portion for containing the developer, and the housing provided with the housing, wherein the driving force is transmitted to the developer containing portion. A stirring member that stirs the developer, a first rotating body that is rotatably supported by the casing and to which a driving force is transmitted, and a second rotor that is rotatably supported by the casing and connected to the stirring member. A rotating body, and an endless transmission body that transmits a driving force from the first rotating body to the second rotating body by being wound between the first rotating body and the second rotating body. An image forming apparatus to which a developing cartridge is detachably mounted, wherein the developer containing portion is detected by the detecting portion that detects that the amount of the developer in the developer containing portion has decreased to a predetermined amount, and the detecting portion contains the developer containing portion. When it is detected that the amount of developer in the portion has decreased to a predetermined amount, Provided from the by the body first rotor and eliminating mechanism for eliminating the driving force transmission state to the second rotary member, the developing cartridge, a developer carrying, driving force is transmitted from the first rotary member A developing roller that rotates, a third gear that is rotatably supported by the housing and connected to the developing roller, a developer is supplied to the developing roller, and a driving force is supplied from the first rotating body. A supply roller that rotates by being transmitted; and a fourth gear that is rotatably supported by the housing and connected to the supply roller. The first rotating body is wound around the transmission body It is characterized by comprising a winding portion and a meshing portion that is disposed away from the winding portion and meshes with the third gear and the fourth gear .

According to a fourth aspect of the present invention, in the third aspect of the present invention, the cancellation mechanism moves between a first position that contacts the transmission body and a second position that is separated from the transmission body. It is possible, and includes a cutting member that cuts the transmission body at the first position, and an actuator that moves the cutting member between the first position and the second position.
The invention according to claim 5 is characterized in that, in the invention according to claim 4, a storage portion for storing the cutting member at the second position is provided.

According to a sixth aspect of the present invention, in the third aspect of the present invention, the canceling mechanism moves between a first position that contacts the transmission body and a second position that is separated from the transmission body. And a detachable member for detaching the transmitting body from at least one of the first rotator and the second rotator at the first position, and the detachable member at the first position and the second position. And an actuator that moves between them.

  According to the first aspect of the present invention, in the developing cartridge, the first rotating body that is rotatably supported by the casing and to which the driving force is transmitted, and the casing is rotatably supported by the casing and the stirring member. An endless transmission body is wound between the connected second rotating bodies. When the transmission body transmits the driving force from the first rotating body to the second rotating body, the driving force for stirring the developer in the developer accommodating portion is transmitted to the stirring member.

And when transmitting a driving force from a 1st rotary body to a 2nd rotary body by winding a transmission body between a 1st rotary body and a 2nd rotary body in this way, Even if the inter-axis distance with the second rotating body is changed, the first rotating body and the second rotating body can continue to be used if only the transmission body is changed.
As a result, the first rotating body and the second rotating body can be used in common in other types of developing cartridges.

Further, according to the present invention, the first rotating body can transmit not only the driving force to the stirring member via the second rotating body but also the driving force to the developing roller and the supply roller.
Since the developing roller and the supply roller rotate by transmitting the driving force from the first rotating body, the developer can be supplied from the supply roller to the developing roller, and the developer can be carried on the developing roller. Thereby, the electrostatic latent image is visualized by the developer carried on the developing roller, and image formation can be achieved.
According to the present invention, when an endless transmission body is wound between the first rotating body and the second rotating body, a gear is disposed between the first rotating body and the second rotating body. As compared with the case where the driving force is transmitted from the first rotating body to the second rotating body, a relatively large free space is provided in the region surrounded by the first rotating body, the second rotating body, and the transmitting body on the side wall of the housing. Can be secured. Thereby, the protrusion member which protrudes toward the outer side of a housing | casing can be arrange | positioned in this area | region. That is, the degree of freedom in design can be increased with respect to the arrangement of the protruding members.
Further, according to the present invention, the region surrounded by the first rotating body, the second rotating body, and the transmission body on the side wall of the housing includes the reflecting member that reflects the detection light and the detection light reflected by the reflecting member. A projecting member including a plurality of parts such as a passing path to be passed can be arranged.

According to invention of Claim 2, when winding an endless transmission body between a 1st rotary body and a 2nd rotary body, between a 1st rotary body and a 2nd rotary body. Compared to the case where the gear is arranged to transmit the driving force from the first rotating body to the second rotating body, the region surrounded by the first rotating body, the second rotating body, and the transmitting body on the side wall of the housing is relatively large. Free space can be secured. Thereby, the window which allows detection light to pass through can be arranged in this region. That is, the degree of freedom in design can be increased with respect to the layout of the windows.

According to the third aspect of the present invention, in the image forming apparatus, when the detection unit detects that the amount of the developer in the developer storage unit has decreased to a predetermined amount, the canceling mechanism is based on the transmission body. The driving force transmission state from the first rotating body to the second rotating body is eliminated.

  Accordingly, the driving force for stirring the developer in the developer accommodating portion is not transmitted to the agitating member to which the second rotating body is connected, so the amount of developer in the developer accommodating portion is reduced to a predetermined amount. After that, the drive of the stirring member can be stopped. Here, when the amount of the developer in the developer container is reduced to a predetermined amount, the developer in the developer container may be deteriorated, but the drive of the stirring member is stopped, so the developer container It is possible to prevent the deteriorated developer in the portion from being stirred by the stirring member and used for image formation.

According to the fourth aspect of the present invention, in the canceling mechanism, the actuator moves the cutting member to the first position and contacts the transmission body, so that the cutting member cuts the transmission body at the first position. The state in which the driving force is transmitted from the first rotating body to the second rotating body by the body can be reliably eliminated.
According to the fifth aspect of the present invention, since the cutting member at the second position that is separated from the transmission body is stored in the storage unit, the cutting member at the second position interferes with surrounding components in the image forming apparatus. Can be prevented.

According to the sixth aspect of the present invention, in the canceling mechanism, the actuator moves the detaching member to the first position to contact the transmitting body, so that the detaching member moves the transmitting body to the first rotating body and the first position. Since it is made to detach | leave from at least any one of a 2nd rotary body, the driving force transmission state from the 1st rotary body by a transmission body to a 2nd rotary body can be eliminated reliably.

1. Configuration of Laser Printer FIG. 1 is a side sectional view schematically showing a configuration of a laser printer as an example of an image forming apparatus of the present invention.
In the laser printer 1, an image is formed in a main body casing 2, a paper feeding unit 4 for feeding paper 3, an image forming unit 5 for forming an image on the fed paper 3, and an image. A paper discharge unit 6 for discharging the paper 3 is provided.
(1) Main Body Casing A front cover 7 is provided on one side surface of the main body casing 2 so as to be freely opened and closed. By opening the front cover 7, a process cartridge 13 described later can be attached to and detached from the main body casing 2.

In the following description, the side where the front cover 7 is provided (the right side in FIG. 1) is the front side (front side), and the opposite side (the left side in FIG. 1) is the rear side (back side). Further, when the laser printer 1 is viewed from the front side, the left and right reference is used. The process cartridge 13 will be described with reference to the direction in the mounting state with respect to the main casing 2 unless otherwise specified.
(2) Paper Feed Unit The paper feed unit 4 includes a paper feed tray 8 for storing the paper 3 in a stacked state. The paper feed tray 8 is detachably attached to the bottom of the main casing 2. A paper feed roller 9 is disposed above the front end of the paper feed tray 8. By the rotation of the paper feed roller 9, the paper 3 stored in the paper feed tray 8 is sent out one by one to the paper transport path 10. The fed sheet 3 passes through the sheet conveyance path 10, is registered by the registration roller 11, and is conveyed toward the image forming unit 5 (between the photosensitive drum 18 and the transfer roller 20).
(3) Image Forming Unit The image forming unit 5 includes a scanner unit 12, a process cartridge 13, and a fixing unit 14.
(3-1) Scanner Unit The scanner unit 12 is arranged on the upper part of the main body casing 2. The scanner unit 12 includes optical members such as a laser light emitting unit, a mirror, and a lens, and emits a laser beam toward a photosensitive drum 18 described later.
(3-2) Process Cartridge The process cartridge 13 is detachably attached to the main body casing 2 below the scanner unit 12.

The process cartridge 13 includes a drum cartridge 15 and a developing cartridge 16 that is detachably attached to the drum cartridge 15.
The drum cartridge 15 includes a drum cartridge housing 17. The drum cartridge housing 17 is formed in a box shape in which the rear half of the upper surface is closed and the front half of the upper surface is opened. In the drum cartridge housing 17, a photosensitive drum 18, a scorotron charger 19, a transfer roller 20, and a cleaning brush 21 are held in a rear half portion whose upper surface is closed.

The photosensitive drum 18 and the transfer roller 20 are provided so as to be rotatable about axes extending in the left-right direction. The scorotron charger 19 is disposed on the upper rear side of the photosensitive drum 18. The transfer roller 20 is disposed below the photosensitive drum 18. The cleaning brush 21 is disposed on the rear side of the photosensitive drum 18.
The front half of the drum cartridge housing 17 whose upper surface is opened is a cartridge mounting portion 22 to which the developing cartridge 16 is detachably mounted.

  The developing cartridge 16 includes a developing cartridge housing 24 as an example of a housing. The developing cartridge housing 24 is formed in a box shape whose rear surface is opened. That is, the developing cartridge housing 24 includes a pair of side walls 25 that are opposed to each other at an interval in the left-right direction, an upper wall 26 that closes the side walls 25 from above, and a lower wall that closes the side walls 25 from below. 27 and a front wall 28 that connects the front end edges of the side walls 25, the upper wall 26, and the lower wall 27 are integrally provided.

In the developing cartridge housing 24, a toner storage chamber 29 as an example of a developer storage portion and a developing chamber 30 are formed side by side.
In the toner storage chamber 29, for example, a positively charged nonmagnetic one-component toner is stored as an example of a developer. In the toner storage chamber 29, an agitator 31 is provided as an example of a stirring member that stirs the toner by rotating. The agitator 31 includes an agitator shaft 31A that extends in the left-right direction and is rotatably supported on both side walls 25, and a blade 31B that is attached to the agitator shaft 31A. The blade 31B extends from the agitator shaft 31A in a direction intersecting with the left-right direction. In the agitator 31, the blade 31B rotates together with the agitator shaft 31A to agitate the toner in the toner storage chamber 29.

In the developing chamber 30, a supply roller 32, a developing roller 33, and a layer thickness regulating blade 34 are provided.
The supply roller 32 is disposed on the rear side of the boundary portion with the toner storage chamber 29 in the developing chamber 30. The supply roller 32 is rotatably provided around an axis extending in the left-right direction. The shaft of the supply roller 32 (supply roller shaft 32A) is rotatably supported by the side walls 25.

  The developing roller 33 has a configuration in which a metal developing roller shaft 33A is covered with a conductive rubber material. Both ends of the developing roller shaft 33A are rotatably supported by the side walls 25. The developing roller 33 is disposed behind the supply roller 32, and the front peripheral surface thereof is in contact with the peripheral surface of the supply roller 32. When the developing cartridge 16 is mounted on the drum cartridge 15, the rear peripheral surface of the developing roller 33 comes into contact with the peripheral surface of the photosensitive drum 18 through the rear surface opened in the developing cartridge housing 24. Yes. A predetermined developing bias is supplied to the developing roller 33.

The layer thickness regulating blade 34 includes a rubber member at one end of a thin sheet metal. The other end of the sheet metal is fixed to the developing cartridge housing 24, and is provided so that the rubber member presses the developing roller 33.
In the developing cartridge 16, the toner stored in the toner storage chamber 29 is fed into the developing chamber 30 while being stirred by the agitator 31. The toner fed into the developing chamber 30 is supplied to the supply roller 32 and is supplied from the supply roller 32 to the developing roller 33. At this time, the toner is triboelectrically charged between the supply roller 32 and the developing roller 33 to which a developing bias is applied. As the developing roller 33 rotates, excess toner is scraped off from the developing roller 33 by the layer thickness regulating blade 34, so that a thin layer of toner having a constant thickness is carried on the developing roller 33.

On the other hand, in the drum cartridge 15, the surface of the photosensitive drum 18 is uniformly positively charged by corona discharge of the scorotron charger 19. The surface of the positively charged photosensitive drum 18 is irradiated with a laser beam (see the dotted line in the figure) from the scanner unit 12, thereby forming an electrostatic latent image corresponding to the image to be formed on the paper 3. .
When the electrostatic latent image formed on the surface of the photosensitive drum 18 is opposed to the developing roller 33 by the rotation of the photosensitive drum 18, the positively charged toner carried on the surface of the developing roller 33 is changed to the electrostatic latent image. Supplied to the image. As a result, the electrostatic latent image is visualized and a toner image is carried on the surface of the photosensitive drum 18.

The toner image is transferred to the sheet 3 conveyed between the photosensitive drum 18 and the transfer roller 20 by a transfer bias applied to the transfer roller 20. The sheet 3 on which the toner image has been transferred in this way is conveyed toward the fixing unit 14.
The toner remaining on the photosensitive drum 18 after the transfer is collected by the developing roller 33. Further, paper dust from the paper 3 adhering to the photosensitive drum 18 after the transfer is collected by the cleaning brush 21.
(3-3) Fixing Unit The fixing unit 14 is provided behind the process cartridge 13. The fixing unit 14 includes a heating roller 36 and a pressure roller 37. The pressure roller 37 is pressed against the heating roller 36 from below. While the sheet 3 passes between the heating roller 36 and the pressure roller 37, the toner image transferred to the sheet 3 is fixed to the sheet 3 by heating and pressing.
(4) Paper Discharge Unit The paper discharge unit 6 includes a paper conveyance path 38 having a substantially C-shaped cross section that is open toward the front. The sheet 3 conveyed from the fixing unit 14 passes through the sheet conveying path 38 and is discharged by a sheet discharge roller 39 onto a sheet discharge tray 40 formed on the upper surface of the main casing 2.
2. Developing Cartridge FIG. 2 is a left side view of the developing cartridge. FIG. 3 is a plan view of the developing cartridge, and shows the periphery of the left side surface of the developing cartridge. FIG. 4 is a plan view of the laser printer, in which the periphery of the left side surface of the developing cartridge is extracted.

  As shown in FIG. 2, in the developing cartridge 16, an example of the first rotating body is provided on the left side surface of the left side wall 25 of the developing cartridge housing 24 (hereinafter referred to as the left side wall 25L as an example of the side wall). A first gear 42, a second gear 43 as an example of a second rotating body, a third gear 44, a fourth gear 45, and a belt 47 as an example of an endless transmission body are arranged. The first gear 42, the second gear 43, the third gear 44, and the fourth gear 45 are all cylindrical with a central axis extending in the left-right direction, and gear teeth are formed on the outer peripheral surface thereof (see FIG. (See dotted line part 3).

  With respect to the first gear 42, a first gear support shaft 46 that protrudes to the left side is provided on the left side wall 25L at a position corresponding to the upper side of the supply roller 32 (see FIG. 1). A first gear support shaft 46 is inserted through a circle center portion of the first gear 42. In this state, the first gear 42 can rotate relative to the first gear support shaft 46 around the first gear support shaft 46. That is, the first gear 42 is rotatably supported by the left side wall 25L (developing cartridge housing 24) via the first gear support shaft 46.

  Regarding the second gear 43, the left end portion of the agitator shaft 31A (see FIG. 1) is exposed to the left side from the left side wall 25L. The left end portion of the agitator shaft 31 </ b> A is inserted through the circular center portion of the second gear 43. In this state, the second gear 43 is fixed to the agitator shaft 31A and rotates together with the agitator shaft 31A. That is, the second gear 43 is connected to the agitator 31. The second gear 43 is rotatably supported by the left side wall 25L (developing cartridge housing 24) via the agitator shaft 31A.

Regarding the third gear 44, the left end portion of the developing roller shaft 33A (see FIG. 1) of the developing roller 33 is exposed to the left from the left side wall 25L. The left end portion of the developing roller shaft 33 </ b> A is inserted through the circular center portion of the third gear 44. In this state, the third gear 44 is fixed to the developing roller shaft 33A and rotates together with the developing roller shaft 33A (that is, the developing roller 33).
With respect to the fourth gear 45, the left end portion of the supply roller shaft 32A (see FIG. 1) of the supply roller 32 is exposed to the left from the left side wall 25L. The left end portion of the supply roller shaft 32 </ b> A is inserted into the circle center portion of the fourth gear 45. In this state, the fourth gear 45 is fixed to the supply roller shaft 32A and rotates together with the supply roller shaft 32A (that is, the supply roller 32).

The belt 47 described above is provided for the first gear 42 and the second gear 43. The belt 47 is a so-called toothed endless belt having irregularities (teeth) formed on the inner peripheral surface thereof. The belt 47 is made of a flexible material such as rubber. The belt 47 is wound between the left side portion (winding portion) of the first gear 42 and the second gear 43 (see also FIG. 3). In this state, the teeth of the belt 47 mesh with the gear teeth of the first gear 42 (specifically, the left side portion (winding portion) ) and the second gear 43.

The gear teeth of the third gear 44 mesh with the gear teeth of the first gear 42 (specifically, the right portion (meshing portion) away from the belt 47) from the rear side. The teeth mesh with the gear teeth of the first gear 42 (specifically, the right portion (meshing portion) away from the belt 47) from below (see also FIG. 3). The third gear 44 and the fourth gear 45 are not meshed.
Here, a motor casing (not shown) is provided in the main casing 2 (see FIG. 1). When the process cartridge 13 is mounted on the main casing 2, the motor output section is connected to the first gear 42. Connected to When a motor (not shown) is driven in this state, the driving force generated by the motor is transmitted from the output portion of the motor to the first gear 42, and the first gear 42 rotates clockwise as viewed from the left side. . Accordingly, the driving force is transmitted from the first gear 42 to the third gear 44 and the fourth gear 45 that mesh with the first gear 42, and the third gear 44 and the fourth gear 45 are counterclockwise as viewed from the left side. Rotate to. As a result, the driving force is transmitted from the third gear 44 and the developing roller 33 (see FIG. 1) rotates counterclockwise as viewed from the left side, and the driving force is transmitted from the fourth gear 45 to supply roller 32 (see FIG. 1). 1) rotates counterclockwise in the left side view.

  Further, the driving force transmitted from the motor output unit (not shown) to the first gear 42 is also transmitted to the second gear 43 by the belt 47, whereby the second gear 43 rotates. As a result, the driving force is transmitted from the second gear 43 and the agitator 31 rotates. At this time, the belt 47 rotates clockwise as viewed from the left side, and the second gear 43 and the agitator 31 also rotate clockwise as viewed from the left side.

  Further, in the left side wall 25L, a through hole 48 communicating with the toner storage chamber 29 is formed in a portion corresponding to the toner storage chamber 29 (see FIG. 1) (in other words, defining the toner storage chamber 29). The through hole 48 is closed without a gap by a substantially transparent window 49 provided in the left side wall 25L. Specifically, the through hole 48 and the window 49 are provided in a region 50 surrounded by the first gear 42, the second gear 43, and the belt 47 in the left side wall 25L. The inside of the toner storage chamber 29 can be grasped through the window 49. Although not shown, this window 49 is also provided on the right side wall 25 of the developing cartridge housing 24. These windows 49 are opposed in the left-right direction.

Here, regarding the window 49, the laser printer 1 is provided with a detection unit 51 and a light guide member 53 as an example of a protruding member, as shown in FIG. 4. In FIG. 4, members other than the developing cartridge 16 are omitted from the process cartridge 13 for convenience of explanation.
3. Detection Unit and Light Guide Member The detection unit 51 is provided in the main casing 2 and includes an optical sensor 52 and a CPU (not shown) electrically connected to the optical sensor 52.

  The optical sensor 52 includes a light emitting element 54 that emits detection light and a light receiving element 55 that receives the detection light emitted from the light emitting element 54. The light emitting element 54 and the light receiving element 55 are arranged in the main casing 2 so as to sandwich the developing cartridge 16 from the left and right directions. Specifically, the light emitting element 54 is provided on the wall (main body wall 2A) facing the left side wall 25L of the developing cartridge 16 in the main body casing 2, and the light receiving element 55 is provided on the right side wall 25 of the developing cartridge 16 in the main body casing 2. It is provided on the opposing wall (not shown).

  The light guide member 53 is provided in the developing cartridge housing 24. The light guide member 53 is not illustrated except for FIG. The light guide member 53 is disposed around the window 49 (specifically, the region 50 described above) in the left side wall 25L of the developing cartridge housing 24 and protrudes toward the outside (left side) of the developing cartridge housing 24, for example, substantially transparent. It is a hollow body. The light guide member 53 includes two thin plate-like reflecting members 58 in the hollow portion 53A. Of the two reflecting members 58, one reflecting member 58A is disposed so as to incline obliquely rearward on the front side of the hollow portion 53A, and the other reflecting member 58B is disposed obliquely on the right side on the rear side of the hollow portion 53A. It arrange | positions so that it may incline back. A mirror 59 is provided on the surfaces of the two reflecting members 58A and 58B that are close to each other. The mirror 59 of the other reflecting member 58B is shifted to the left with respect to the window 49 of the left side wall 25L of the developing cartridge 16.

In a state where the developing cartridge 16 is mounted on the main casing 2, the mirror 59 of the one reflecting member 58 </ b> A is in a position shifted to the right side with respect to the light emitting element 54 of the optical sensor 52.
Such a light guide member 53 may be provided on the right side wall 25 of the developing cartridge 16.

  Here, the detection light emitted from the light-emitting element 54 enters the hollow portion 53 </ b> A of the light guide member 53 after proceeding to the right side, as indicated by the one-dot chain line shown in the drawing. This detection light is reflected by the mirror 59 of the one reflecting member 58A in the hollow portion 53A, so that its traveling direction is directed to the mirror 59 (rear side in FIG. 4) of the other reflecting member 58B. Next, the detection light is reflected by the mirror 59 of the other reflecting member 58B, and the traveling direction thereof is directed to the window 49 (that is, the right side) of the left side wall 25L and goes out of the light guide member 53. Here, the hollow portion 53A is an example of a detection light passing path. Then, the detection light that has come out of the light guide member 53 passes through the window 49 of the left side wall 25 </ b> L and enters the toner storage chamber 29. The detection light incident on the toner storage chamber 29 travels to the right, passes through a window 49 (not shown) on the right side wall 25 of the developing cartridge 16, is emitted from the toner storage chamber 29, and is received by the light receiving element 55. .

  Specifically, in the toner storage chamber 29, when toner is stored above the window 49 on the left side wall 25 </ b> L, the detection light that has reached the window 49 on the left side wall 25 </ b> L is blocked in the window 49 by the toner. Then, it is not incident on the toner storage chamber 29. For this reason, the detection light is not received by the light receiving element 55, whereby the detection unit 51 (specifically, the CPU described above) detects that a predetermined amount of toner is stored in the toner storage chamber 29. On the other hand, if the amount of toner in the toner storage chamber 29 decreases to a predetermined amount and the toner does not exist in the vicinity of the window 49 on the left side wall 25L, the detection light that has reached the window 49 on the left side wall 25L enters the toner storage chamber 29. Since the light is incident and received by the light receiving element 55 as described above, the detection unit 51 detects that the amount of toner in the toner storage chamber 29 has decreased to a predetermined amount.

Thus, this detection light detects the amount of toner in the toner storage chamber 29. Note that, as described above, the amount of toner in the toner storage chamber 29 may be detected based on the amount of detection light received by the light receiving element 55, regardless of whether the detection light is received by the light receiving element 55.
4). Cutter FIG. 5 is a view of a vertical cross section of the laser printer as seen from the back, and shows the periphery of the left side surface of the developing cartridge.

In relation to the detection of the toner amount by the detection unit 51 described above, the body wall 2A of the body casing 2 is provided with a cutter 60 as an example of a cutting member shown in FIG. In FIG. 5, the detection unit 51 is omitted.
The cutter 60 integrally includes a hollow cylindrical tube portion 60A and a hook portion 60B that extends from the upper end of the right end of the tube portion 60A to the right side and then bends obliquely downward to the left. A threaded portion is formed on the inner peripheral surface of the cylindrical portion 60A. A blade 62 is formed at the left end and the right end of the hook portion 60B that is bent obliquely leftward and downward. A key 61 is formed at the upper end of the cutter 60 and extends upward while extending in the left-right direction. The key 61 is loosely fitted in a key groove (not shown) provided in the main body wall 2A.

  Regarding the cutter 60, an actuator 63 is provided on the main body wall 2 </ b> A of the main body casing 2. The cutter 60 and the actuator 63 constitute an example of a cancellation mechanism. The actuator 63 includes a motor (not shown) and a columnar gear 64 having a central axis extending in the left-right direction. Gear teeth that mesh with an output gear (not shown) provided on the output shaft of the motor (not shown) are formed on the outer peripheral surface of the gear 64. A screw 65 extending rightward from the center of the circle is integrally provided on the right end surface of the gear 64.

  Here, in the cutter 60, the cylindrical portion 60A is externally fitted to the screw 65 of the gear 64, and the screw portion on the inner peripheral surface of the cylindrical portion 60A and the screw 65 are engaged with each other. In this state, when the actuator 63 (more specifically, the motor (not shown) described above) is operated, the gear 64 rotates forward or backward around its central axis. Along with this, the screw 65 of the gear 64 also rotates. Here, since the key 61 of the cutter 60 is loosely fitted in the key groove (not shown) of the main body wall 2A as described above, the cutter 60 does not rotate together with the screw 65 and rotates the screw 65. It moves to the left and right with it.

  In the following, the position of the cutter 60 when it has moved to the left is defined as the first position (see the cutter 60 indicated by the dotted line in the figure). Then, the position of the cutter 60 when it has moved to the right side is set as the second position (see the cutter 60 indicated by the solid line in the drawing). Thus, the actuator 63 moves the cutter 60 between the first position and the second position. The main body wall 2 </ b> A is provided with a recess 66 as an example of a storage portion, and the cutter 60 in the second position is stored in the recess 66. With the cutter 60 in the second position, the blade 62 on the right side of the cutter 60 is connected to the belt 47 (more specifically, as shown in FIG. 2, the upper side connecting the upper end of the first gear 42 and the upper end of the second gear 43 in the belt 47). The connecting portion 47A) is shifted from the left side.

  Usually, the cutter 60 is in the second position. However, when the detection unit 51 detects that the amount of toner in the toner storage chamber 29 has decreased to a predetermined amount as described above, the actuator 63 is activated, and the cutter 60 protrudes from the recess 66 to the first position. Move and immediately return to the second position. Specifically, while the cutter 60 is moving to the first position, the blade 62 on the right side of the cutter 60 contacts the upper connecting portion 47A of the belt 47 and starts to cut the upper connecting portion 47A. When the cutter 60 moves to the first position, the right blade 62 of the cutter 60 completely cuts the upper connecting portion 47A. That is, the cutter 60 cuts the belt 47 at the first position. As a result, the belt 47 is not wound between the first gear 42 and the second gear 43, and the driving force transmission state (see FIG. 2) from the first gear 42 to the second gear 43 by the belt 47 is eliminated. The If the belt 47 (upper connecting portion 47A) is not completely cut even though the cutter 60 has moved to the first position, the belt 47 is moved while the cutter 60 returns from the first position to the second position. The blade 60 is cut by the left blade 62 of the cutter 60.

Thus, the first position is a position in contact with the belt 47, and the second position is a position away from the belt 47.
5. Operation and Effect (1) In this developing cartridge 16, as shown in FIG. 2, the first gear 42 that is rotatably supported by the developing cartridge housing 24 and to which the driving force is transmitted, and the developing cartridge housing 24 are rotatable. An endless belt 47 is wound between the second gear 43 and the second gear 43 supported by the agitator 31. The belt 47 transmits a driving force from the first gear 42 to the second gear 43, whereby a driving force for stirring the toner in the toner storage chamber 29 (see FIG. 1) is transmitted to the agitator 31.

When the driving force is transmitted from the first gear 42 to the second gear 43 by winding the belt 47 between the first gear 42 and the second gear 43 as described above, Even if the distance between the shafts with the second gear 43 is changed, if only the belt 47 is changed, the first gear 42 and the second gear 43 can continue to be used.
As a result, the first gear 42 and the second gear 43 can be used in common in the developing cartridges 16 of other models.
(2) The first gear 42 can transmit not only the driving force to the agitator 31 through the second gear 43 but also the driving force to the developing roller 33 and the supply roller 32.

Since the developing roller 33 and the supply roller 32 are rotated by the driving force transmitted from the first gear 42, the toner is supplied from the supply roller 32 to the developing roller 33, and the toner is carried on the developing roller 33. Yes (see FIG. 1). Thereby, the electrostatic latent image is visualized by the toner carried on the developing roller 33, and image formation can be achieved.
(3) When the endless belt 47 is wound between the first gear 42 and the second gear 43, another gear is arranged between the first gear 42 and the second gear 43. Compared to the case where the driving force is transmitted from the first gear 42 to the second gear 43, the area 50 surrounded by the first gear 42, the second gear 43 and the belt 47 in the left side wall 25 </ b> L of the developing cartridge housing 24 is relatively large. Free space can be secured. As a result, a window 49 that allows detection light to pass through can be arranged in this region 50. That is, the degree of freedom in design can be increased with respect to the arrangement of the windows 49.
(4) Further, as shown in FIG. 4, a light guide member 53 protruding toward the outside of the developing cartridge housing 24 can be disposed in this region 50. That is, the degree of freedom in design can be increased with respect to the arrangement of the light guide member 53.
(5) Specifically, in the region 50, the light guide includes a plurality of components such as two reflecting members 58 that reflect the detection light and a passage path (hollow portion 53A) that allows the detection light reflected by the reflecting member 58 to pass therethrough. The member 53 can be arranged. In this embodiment, the hollow portion 53A of the light guide member 53 is used as the passage route. However, the passage route may be provided separately from the hollow portion 53A, and this passage route may be arranged in the hollow portion 53A.
(6) In this laser printer 1, when the detection unit 51 detects that the amount of toner in the toner storage chamber 29 has decreased to a predetermined amount, the cutter 60 and the actuator 63 operate as shown in FIG. Thus, the driving force transmission state from the first gear 42 to the second gear 43 by the belt 47 is canceled.

  Accordingly, the driving force for stirring the toner in the toner storage chamber 29 (see FIG. 1) is not transmitted to the agitator 31 (see FIG. 2) to which the second gear 43 is connected. The driving of the agitator 31 can be stopped after the toner amount is reduced to a predetermined amount. Here, when the amount of toner in the toner storage chamber 29 decreases to a predetermined amount, the toner in the toner storage chamber 29 may be deteriorated, and such toner is supplied to the photosensitive drum 18 (see FIG. 1). Then, the photosensitive drum 18 may be damaged. However, since the drive of the agitator 31 is stopped when the amount of toner in the toner storage chamber 29 decreases to a predetermined amount, the deteriorated toner in the toner storage chamber 29 is not supplied to the photosensitive drum 18, and the photosensitive drum 18 caused by the deteriorated toner. Can prevent damage. The deteriorated toner in the toner storage chamber 29 can be prevented from being stirred by the agitator 31 and used for image formation.

When the drive of the agitator 31 is stopped, image formation is performed until the toner in the supply roller 32 and the developing roller 33 in the developing chamber 30 (see FIG. 1) runs out, and then the toner empty to the user. Is notified. Whether or not the toner in the developing chamber 30 runs out is determined by, for example, the number of image formations after the drive of the agitator 31 is stopped.
(7) Regarding the cancellation of the driving force transmission state from the first gear 42 to the second gear 43 by the belt 47, specifically, the actuator 63 moves the cutter 60 to the first position (see the cutter 60 indicated by the dotted line in the drawing). And the cutter 60 cuts the belt 47 at the first position. Thereby, the driving force transmission state from the first gear 42 to the second gear 43 by the belt 47 can be reliably eliminated.
(8) Since the cutter 60 in the second position (see the cutter 60 indicated by the solid line in the drawing) separated from the belt 47 is accommodated in the recess 66, the cutter 60 in the second position is located around the periphery of the laser printer 1. Interference with components can be prevented.
6). Modification (1) Modification 1
FIG. 6 is a diagram in which the first modification is applied to FIG.

  In the embodiment described above, the belt 47 is a toothed belt, but may be a belt without teeth. In this case, as shown in FIG. 6, a first pulley 70 is provided instead of the first gear 42 (see FIG. 3), and a second pulley 71 is provided instead of the second gear 43 (see FIG. 3). The outer peripheral surfaces of the first pulley 70 and the second pulley 71 are recessed over the entire circumference. Here, the recess on the outer peripheral surface of the first pulley 70 is referred to as a first recess 70A, and the recess on the outer peripheral surface of the second pulley 71 is referred to as a first recess 71A. In the first pulley 70, the first recess 70A is provided on the left side of the first pulley 70, and gear teeth are formed on the outer peripheral surface on the right side of the first pulley 70 (see the dotted line portion). As described above, the gear teeth of the third gear 44 and the fourth gear 45 mesh with the gear teeth.

As described above, the belt 47 without teeth is wound between the first pulley 70 and the second pulley 71, and the first recess 70 </ b> A of the first pulley 70 and the second recess of the second pulley 71. It is fitted in each of 71A.
Further, the belt 47 includes an endless and flexible chain. In this case, the first gear 42 and the second gear 43 (see FIG. 3) form a sprocket.
(2) Modification 2
FIG. 7 is a diagram in which the second modification is applied to FIG.

In the second modification, a detaching member 67 shown in FIG. 7 is provided instead of the cutter 60 (see FIG. 5). That is, in the second modification, the detaching member 67 and the actuator 63 constitute an example of a cancellation mechanism.
The detaching member 67 has a substantially cylindrical shape extending in the left-right direction, and a thread portion is formed on the inner peripheral surface thereof. A substantially V-shaped recess 68 is formed on the right end surface of the detachable member 67. Further, similarly to the cutter 60, a key 61 that is loosely fitted in a key groove (not shown) of the main body wall 2A is formed on the upper end of the detachable member 67.

  Here, the detachable member 67 is externally fitted to the screw 65 of the gear 64, and the screw portion of the inner peripheral surface of the detachable member 67 and the screw 65 are engaged with each other. In this state, when the actuator 63 (the motor (not shown in detail) described above) operates, the actuator 63 causes the detachment member 67 to contact the belt 47 in the first position (as in the case of the cutter 60 (see FIG. 5)). It is moved to the left and right between a separation member 67 shown by a dotted line in the drawing) and a second position (see the separation member 67 shown by a solid line in the drawing) separated from the belt 47. Here, the moving direction (left-right direction) between the first position and the second position of the detaching member 67 is a direction orthogonal to the circumferential movement direction of the belt 47.

  Usually, the detaching member 67 is in the second position and is accommodated in the recess 66 as in the case of the cutter 60. However, when the detection unit 51 detects that the amount of toner in the toner storage chamber 29 has decreased to a predetermined amount as described above, the actuator 63 is activated, and the detaching member 67 protrudes from the recess 66 to the first position. And immediately return to the second position. Specifically, in the middle of the movement of the cutter 60 to the first position, the detaching member 67 comes into contact with the upper connecting portion 47A of the belt 47 around the recess 68 and starts to push the upper connecting portion 47A to the right. When the detaching member 67 moves to the first position, the detaching member 67 further pushes the upper connecting portion 47A to the right side, and accordingly, the belt 47 moves between the first gear 42 and the second gear 43 (see FIG. 2). Detach from at least one of them (see belt 47 indicated by dotted line in the figure). As a result, the belt 47 is not wound between the first gear 42 and the second gear 43.

In this way, the actuator 63 moves the detaching member 67 to the first position to contact the belt 47, so that the detaching member 67 causes the belt 47 to move to the first gear 42 or at least one of the second gear 43 in the first position. Since it is made to detach | leave from one side, the driving force transmission state (refer FIG. 2) from the 1st gear 42 to the 2nd gear 43 by the belt 47 can be eliminated reliably.
(3) Modification 3
In the above-described embodiment, a monochrome printer has been exemplified. However, for example, the present invention can be applied to a color printer.

Further, although the photosensitive drum 18 is exposed by the laser generated by the scanner unit 12, the photosensitive drum 18 may be exposed using an LED instead of the scanner unit 12.
(4) Modification 4
The detection of the amount of toner in the toner storage chamber 29 described above is not limited to being performed by the detection unit 51, and may be performed according to, for example, the number of images formed.
(5) Modification 5
In the above-described embodiment, as shown in FIG. 2, the belt 47 is wound between the first gear 42 and the second gear 43, but a gear that meshes with the first gear 42 is newly added to the developing cartridge 16. The belt 47 may be wound between the gear and the second gear 43.

  Further, relay gears may be interposed between the first gear 42 and the third gear 44 and between the first gear 42 and the fourth gear 45, respectively. In this case, the driving force is transmitted from the first gear 42 to the third gear 44 via the relay gear between the first gear 42 and the third gear 44, and between the first gear 42 and the fourth gear 45. A driving force is transmitted from the first gear 42 to the fourth gear 45 via the relay gear.

1 is a side sectional view schematically showing a configuration of a laser printer as an example of an image forming apparatus of the present invention. FIG. 6 is a left side view of the developing cartridge. It is a top view of a developing cartridge, Comprising: The left side surface periphery of a developing cartridge is extracted and shown. It is a top view of a laser printer, Comprising: The left side periphery of a developing cartridge is extracted and shown. It is the figure which looked at the longitudinal cross-section of the laser printer from the back, Comprising: The left side periphery of the developing cartridge is extracted and shown. It is the figure which applied the modification 1 to FIG. It is the figure which applied the modification 2 to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Printer 16 Developing cartridge 24 Developing cartridge housing 25L Left side wall 29 Toner storage chamber 31 Agitator 32 Supply roller 33 Developing roller 42 First gear 43 Second gear 47 Belt 49 Window 50 Area 51 Detector 53 Light guide member 53A Hollow portion 58 Reflective member 60 Cutter 63 Actuator 66 Dimple 67 Detaching member

Claims (6)

A housing provided with a developer accommodating portion for accommodating the developer;
A stirring member that is provided in the housing and transmits the driving force to stir the developer in the developer container;
A first rotating body that is rotatably supported by the housing and transmits a driving force;
A second rotating body rotatably supported by the housing and connected to the stirring member;
An endless transmission body that transmits a driving force from the first rotating body to the second rotating body by being wound between the first rotating body and the second rotating body;
A developing roller that carries a developer and rotates when a driving force is transmitted from the first rotating body;
A third gear rotatably supported by the housing and connected to the developing roller;
A supply roller that rotates by supplying a developer to the developing roller and transmitting a driving force from the first rotating body;
A fourth gear rotatably supported by the housing and connected to the supply roller;
The first rotating body includes a winding portion around which the transmission body is wound, and a meshing portion that is disposed away from the winding portion and meshes with the third gear and the fourth gear,
The housing includes a side wall on which the first rotating body, the second rotating body, and the transmission body are disposed, and an area surrounded by the first rotating body, the second rotating body, and the transmission body on the side wall. Provided with a projecting member projecting toward the outside of the housing,
The protruding member includes a reflecting member that reflects detection light for detecting the amount of developer in the developer accommodating portion, and a passage path through which the detection light reflected by the reflecting member passes. A developing cartridge. The housing is
A side wall on which the first rotator, the second rotator and the transmission body are disposed, and a side wall of the first rotator, the second rotator and the transmission body, provided in a region surrounded by the first rotator, the second rotator and the transmission body 2. The developing cartridge according to claim 1, further comprising a window through which detection light for detecting the amount of the developer in the developer accommodating portion is passed. A housing provided with a developer containing portion for containing the developer; a stirring member provided in the housing for stirring the developer in the developer containing portion by transmitting a driving force; and the housing A first rotating body that is rotatably supported by the body and to which a driving force is transmitted, a second rotating body that is rotatably supported by the housing and connected to the stirring member, the first rotating body, and the An image in which a developing cartridge including an endless transmission body that transmits a driving force from the first rotation body to the second rotation body is detachably mounted by being wound between the second rotation body and the second rotation body. A forming device,
A detection unit for detecting that the amount of the developer in the developer storage unit has decreased to a predetermined amount;
When the detection unit detects that the amount of the developer in the developer storage unit has decreased to a predetermined amount, the driving force transmission state from the first rotating body to the second rotating body by the transmitting body is changed. With a canceling mechanism to cancel,
The developing cartridge is
A developing roller that carries a developer and rotates when a driving force is transmitted from the first rotating body;
A third gear rotatably supported by the housing and connected to the developing roller;
A supply roller that rotates by supplying a developer to the developing roller and transmitting a driving force from the first rotating body;
A fourth gear rotatably supported by the housing and connected to the supply roller;
With
The first rotating body includes a winding portion around which the transmission body is wound, and a meshing portion that is disposed away from the winding portion and meshes with the third gear and the fourth gear . An image forming apparatus. The elimination mechanism is
A cutting member that is movable between a first position that contacts the transmission body and a second position that is separated from the transmission body, and that cuts the transmission body at the first position;
The image forming apparatus according to claim 3, further comprising an actuator that moves the cutting member between the first position and the second position. The image forming apparatus according to claim 4, further comprising a storage unit that stores the cutting member at the second position. The elimination mechanism is
The movable body is movable between a first position that contacts the transmission body and a second position that is separated from the transmission body, and the transmission body is moved between the first rotary body and the second rotary body at the first position. A detachable member for detachment from at least one of them,
The image forming apparatus according to claim 3, further comprising an actuator that moves the detaching member between the first position and the second position.

Images