JP4924876B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, or a facsimile.

  Patent Document 1 discloses an image forming apparatus in which toner remaining on an image carrier removed by an image carrier cleaning unit is conveyed by a waste toner transfer unit, and the toner is discharged to a waste toner collection container. .

JP 2005-173350 A

  However, the image forming apparatus disclosed in Patent Document 1 has a problem that the waste toner collection container and the waste toner transfer means are increased in size.

  The present invention has been made from the above-described background, and an object thereof is to provide an image forming apparatus capable of downsizing the developer recovery means.

  In order to achieve the above object, an image forming apparatus according to the present invention includes a developing device that is rotatably supported around a support shaft, and a developer collecting unit that collects the developer from the developing device. The developer recovery means includes a recovery path formed on the support shaft.

  Preferably, the developer recovery means has a developer transport path connected from the developing device to a recovery path formed on the support shaft, and the developer transport path rotates about the support shaft. It is supported freely.

  Preferably, the developer collecting means has a developer collecting port formed in the developing device, and when the developing device rotates, the developer collecting port is located at a developer collecting position in the developing device. Get away from.

  Preferably, the developing device rotates between a horizontal position and a lower position inclined downward from the horizontal position, and the developer recovery port is configured so that the developer is rotated when the developing device is rotated to a lower position. Leave the collection position.

  The second image forming apparatus according to the present invention rotates about an image carrier device, a first developer collecting means for collecting the developer remaining on the image carrier of the image carrier device, and a support shaft. A developing device that is freely supported and that develops the latent image held by the image carrier; and a second developer collecting unit that collects the developer from the developing device, and the first developer collecting unit. And the second developer recovery means include a common recovery path formed on the support shaft.

  Preferably, the image carrier device is supported rotatably about the support shaft.

  Preferably, the first developer recovery means has a first developer transport path connected from the image carrier device to a recovery path formed on the support shaft, and the second developer. The collecting means has a second developer conveying path connected from the developing device to a collecting path formed on the support shaft, and the first developer conveying path, the second developer conveying path, Is supported rotatably about the support shaft.

  According to the present invention, since the position of the developer recovery port is fixed even when the image carrier device and the developing device rotate, the developer recovery means can be reduced in size.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an outline of an image forming apparatus 10 according to an embodiment of the present invention.
The image forming apparatus 10 includes an image forming apparatus main body 12, a main body frame 14 is provided inside the image forming apparatus main body 12, and, for example, a one-stage sheet feeding unit 16 is provided below the image forming apparatus main body 12. Is arranged.

  The paper feed unit 16 has a paper feed cassette 18 in which sheets such as paper are stored. A feed roll 20 that feeds paper from the paper feed cassette 18 and a retard roll 22 that sprinkles the fed paper one by one are arranged in the upper vicinity of the rear end of the paper feed cassette 18.

The conveyance path 24 is a sheet path from the feed roll 20 to the discharge port 26, and the conveyance path 24 is in the vicinity of the back side (the left side surface in FIG. 1) of the image forming apparatus main body 12 and is described later from the sheet feeding unit 16. The fixing device 76 is formed in a substantially vertical direction.
A secondary transfer roll 68 and a secondary transfer backup roll 62, which will be described later, are arranged on the upstream side of the fixing device 76 in the conveyance path 24, and the registration roll 28 is located upstream of the secondary transfer roll 68 and the secondary transfer backup roll 62. Is arranged.
In addition, a discharge roll 30 is disposed in the vicinity of the discharge port 26 of the conveyance path 24.

  Therefore, the sheet fed from the sheet feeding cassette 18 of the sheet feeding unit 16 by the feed roll 20 is turned by the retard roll 22 and only the uppermost sheet is guided to the transport path 24 and is temporarily stopped by the registration roll 28. The toner image is transferred between a secondary transfer roll 68 and a secondary transfer backup roll 62, which will be described later, and the transferred toner image is fixed by the fixing device 76, and the discharge port 30 discharges the discharge port 26. Are discharged to a discharge portion 32 provided on the upper portion of the image forming apparatus main body 12.

The main body frame 14 has four concave portions 34 that open downward, and axial end portions (bearings 88 described later) of image holding unit units 38a to 38d (described later) of the image forming unit 36 are respectively disposed below the concave portions 34. Is touching.
The image forming unit 36 includes image carrier units 38a to 38d, developing units 40a to 40d, and LED units 42a to 42d.
Each of the image carrier units 38 a to 38 d has an image carrier 44 made of, for example, a photosensitive drum, and is detachably held by an image carrier unit holding member 46.
The image carrier unit holding member 46 is configured to swing within a predetermined range in the forward and reverse directions with the shaft portion 48 as an axis.

Each of the developing units 40a to 40d is, for example, a trickle developing type developing device that is detachably held by the developing unit holding member 50, and is provided on the front side (right side in FIG. 1) of the image forming apparatus main body 12. Black (Black: K), cyan (Cyan: C), magenta (Magenta: M), and yellow (Yellow: Y) toners are received from the boxes 52a to 52d, respectively, and latent images held by the image holding body 44 are respectively received. , And the deteriorated developer is discharged toward a developer recovery box 54 provided below the image forming unit 36.
The developing unit holding member 50 is configured to swing within a predetermined range in the forward and reverse directions with the shaft portion 48 as an axis.

  The LED units 42a to 42d are optical writing devices that write a latent image on the image carrier 44, and are supported by the developing units 40a to 40d with play that swings in a predetermined range in the forward and reverse directions, respectively.

Further, an intermediate transfer device 56 is provided above the image forming unit 36 to primarily transfer the toner images of the respective colors developed by the developing units 40a to 40d and convey them to a secondary transfer position described later.
The intermediate transfer device 56 includes an intermediate transfer member 58 such as an intermediate transfer belt, primary transfer rolls 60a to 60d, a secondary transfer backup roll 62, a cleaner backup roll 64, and a tension roll 66.

The intermediate transfer body 58 has elasticity, for example, and in the color mode for forming a color image, the toner images held by the image holding bodies 44 are sequentially overlapped at the primary transfer position from the primary transfer roll 60d to the primary transfer roll 60a. The toner image that has been primarily transferred is transferred to a secondary transfer roll 68 described later.
Further, in the black and white mode for forming a black and white image, the intermediate transfer body 58 primarily transfers the toner image only from the image holding body 44 that holds the black toner image, and this primary transferred toner image is a secondary image to be described later. The sheet is conveyed toward the transfer roll 68.
Further, a flat surface portion is formed on the back side (left side surface in FIG. 1) of the intermediate transfer body 58 by a tension roll 66 and a secondary transfer backup roll 62, and this flat surface portion serves as a secondary transfer portion and is conveyed. It faces the road 24.
The cleaner backup roll 64 assists a blade 72 described later to scrape off toner remaining on the intermediate transfer body 58 after the secondary transfer.

A secondary transfer roll 68 is opposed to the secondary transfer backup roll 62 of the intermediate transfer device 56 with the conveyance path 24 interposed therebetween. That is, the secondary transfer position in the secondary transfer portion is between the secondary transfer roll 68 and the secondary transfer backup roll 62, and the secondary transfer roll 68 is intermediate with the assistance of the secondary transfer backup roll 62. The toner image primarily transferred to the transfer body 58 is secondarily transferred onto the paper at the secondary transfer position.
In addition, a predetermined potential difference is generated between the secondary transfer roll 68 and the secondary transfer backup roll 62. For example, when the secondary transfer roll 68 is set to a high voltage, the secondary transfer backup backup The roll 62 is connected to a ground (GND) or the like.

An intermediate transfer body cleaner 70 is provided in contact with the intermediate transfer body 58 on the side opposite to the secondary transfer position.
The intermediate transfer body cleaner 70 includes, for example, a blade 72 that scrapes and cleans toner remaining on the intermediate transfer body 58 after the secondary transfer, and a toner recovery bottle 74 that recovers the toner scraped off by the blade 72. .
The blade 72 is made of urethane rubber, for example. The toner collection bottle 74 has a conveyance member 75 that conveys the collected toner toward a collection path 112 described later.
Further, while the intermediate transfer member 58 conveys the toner image, the blade 72 is always in contact with the intermediate transfer member 58.

  A fixing device 76 is disposed above the secondary transfer position. The fixing device 76 has a heating roll 78 and a pressure roll 80, fixes the toner image secondarily transferred to the sheet by the secondary transfer roll 68 and the secondary transfer backup roll 62, and fixes the toner image to the discharge roll 30. Transport toward.

  Further, in the image forming apparatus main body 12, for example, a control unit 82 that includes a CPU (not shown) and the like and controls each unit constituting the image forming apparatus 10 is provided.

  Next, the image carrier units 38a to 38d and the developing units 40a to 40d will be described in detail. The image carrier units 38a to 38d are configured in substantially the same manner, and the developing units 40a to 40d are also configured in substantially the same manner except that the color to be developed is different. Therefore, the image carrier unit 38a and the developing unit 40a will be described.

FIG. 2 is an enlarged side view showing details of the image carrier unit 38a, the developing unit 40a, and the periphery thereof.
The image carrier unit 38 a is a unit in which the image carrier 44, the charging device 84 and the cleaning device 86 are integrated, and is detachably held by the image carrier unit holding member 46.
As described above, the image carrier unit holding member 46 swings within a predetermined range in the forward and reverse directions with the shaft portion 48 as an axis. For example, the image carrier unit holding member 46 is moved downward in the gravity direction due to the weight of the image carrier unit 38a. ing.
The shaft portion 48 is provided with a discharged developer transport path 87 that transports toner and developer toward a recovery path 112 described later by rotating about the center of the shaft portion 48.

For example, a bearing 88 having an outer diameter larger than that of the image carrier 44 is coaxially provided at the end of the image carrier 44. The bearing 88 contacts the concave portion 34 of the main body frame 14 from below, so that the bearing 88 supports the intermediate transfer body 58 of the intermediate transfer device 56 supported by the main body frame 14 (or the image forming apparatus main body 12). The image carrier 44 is positioned.
The charging device 84 uniformly charges the image carrier 44.

The cleaning device 86 includes a blade 90, a residual toner collection unit 92, and a residual toner collection port 94. After the toner image is transferred from the image carrier 44 to the intermediate transfer member 58, the cleaning device 86 removes toner remaining on the image carrier 44. The toner is scraped off by the blade 90 and collected in the residual toner collecting unit 92.
The collected toner is conveyed from a residual toner collection port 94 toward a residual toner conveyance path 210 described later.
The image carrier unit holding member 46 may be supported at both ends by an elastic member (not shown) such as a spring, for example, and may be urged in a predetermined direction while its swinging range is restricted to a predetermined range.

The developing unit 40a is a unit in which the developing roll 96, the first stirring and conveying member 98, the second stirring and conveying member 100, the gears 101a and 101b, and the like are integrated, and is detachably held by the developing unit holding member 50. ing.
Further, as described above, the developing unit holding member 50 swings within a predetermined range in the forward and reverse directions with the shaft portion 48 as an axis, and moves downward in the direction of gravity, for example, due to the weight of the developing unit 40a. .
Then, the developing unit 40a circulates the toner received from the toner box 52a via the conveyance pipe 106a described later by the first agitation conveyance member 98 and the second agitation conveyance member 100 and agitates and conveys the toner to the development roll 96. The latent image formed on the image carrier 44 is developed by the developing roll 96.
The gear 101 a transmits the driving force of the developing roll 96 to the second stirring and conveying member 100 by engaging with a gear (not shown) provided at each end of the developing roll 96 and the second stirring and conveying member 100. .
The gear 101b engages with a gear (not shown) provided at each end of the second agitating / conveying member 100 and the first agitating / conveying member 98, thereby driving the driving force of the second agitating / conveying member 100 to the first. To the stirring and conveying member 98.

The developing unit 40 a is configured such that the position of the developing roll 96 with respect to the image holding body 44 is determined when a tracking roll (not shown) coaxial with the developing roll 96 contacts the bearing 88 of the image holding body 44. Yes.
Further, both ends of the developing unit holding member 50 may be supported by an elastic member (not shown) such as a spring, for example, and the swinging range may be restricted to a predetermined range and may be biased in a predetermined direction.

Further, the LED unit 42a is supported on the developing unit 40a with play that swings within a predetermined range around the fulcrum 102. The LED unit 42a has a V-shaped groove 104 formed in the upper part, and the groove 104 comes into contact with the outer peripheral surface of the bearing 88 provided at the end of the image carrier 44 from below, so that the upper scanning light Is positioned so that the exit from which the light is emitted is directed to a predetermined position of the image holding body 44.
The image carrier unit 38a, the developing unit 40a, and the LED unit 42a may be integrated in different combinations, or all may be integrated.

Next, means for collecting the residual toner and the deteriorated developer from the image carrier unit 38a and the developing unit 40a and transporting them to the discharged developer transport path 87 will be described.
In FIG. 3, details of the trickle developer transport path 200 and the residual toner transport path 210 are shown.
The trickle developer conveyance path 200 is formed in, for example, a pipe shape, and is formed so as to penetrate the housing of the development unit 40 a from the inside of the development unit 40 a and connect to the discharged developer conveyance path 87.
The trickle developer conveyance path 200 is configured to swing with the developing unit 40a about the center of the discharged developer conveyance path 87.
The trickle developer that has been circulated and deteriorated by the first stirring / conveying member 98 and the second stirring / conveying member 100 in the developing unit 40a is recovered from the trickle developer recovery port 202, and passes through the trickle developer transport path 200. Then, it is conveyed toward the discharged developer conveyance path 87.

The residual toner conveyance path 210 is formed in a pipe shape, for example, and is formed so as to be connected to the discharged developer conveyance path 87 from the residual toner collection port 94.
Further, the residual toner transport path 210 swings with the image carrier unit 38a around the center of the discharged developer transport path 87.
The residual toner transported from the residual toner collection port 94 is transported toward the discharged developer transport path 87 via the residual toner transport path 210.
The discharged developer transport path 87 transports the residual toner transported via the residual toner transport path 210 and the trickle developer transported via the trickle developer transport path 200 together toward the collection path 112. To do.

Next, means for conveying toner from the toner boxes 52a to 52b to the developing units 40a to 40d will be described.
4, transport pipes 106a to 106d that transport toner from the toner boxes 52a to 52b to the developing units 40a to 40d, respectively, are shown.
Each of the transport pipes 106a to 106d is made of, for example, an elastic member, and transports toner of each color from the toner boxes 52a to 52b to the first stirring and transporting member 98 side of the developing units 40a to 40d.

Next, means for collecting the residual toner and the deteriorated trickle developer in the developer collection box 54 will be described.
In FIG. 5, a recovery path 112 for recovering toner and developer from the discharged developer transport path 87 to the developer recovery box 54 is shown.
The recovery path 112 is a pipe for transporting the toner and developer transported by each of the four discharged developer transport paths 87 and the toner transported by the transport member 75 toward the developer recovery box 54 by a transport member (not shown). It is a recovery path.
Accordingly, the toner collected from each of the image holding members 44 and the intermediate transfer member 58 and the developer collected from each of the developing units 40a to 40d are collected in the developer collecting box 54 via the collecting path 112.

Next, the operation of the embodiment of the present invention will be described.
FIG. 6 shows a state where the image carrier 44 is separated from the intermediate transfer member 58 and the developing roller 96 is separated from the image carrier 44.
As described above, the image carrier unit 38a rotates downward about the shaft portion 48 so as to be away from the intermediate transfer member 58, and the developing unit 40a is lowered so as to separate from the image carrier unit 38a about the shaft portion 48. Rotate to.
As the developing unit 40a rotates downward about the shaft portion 48, the developer staying in the developing unit 40a moves in accordance with the rotation of the developing unit 40a.
When the developer moves, the trickle developer recovery port 202 is separated from the developer, so that the trickle developer is not collected when the developing unit 40a is separated from the image carrier unit 38a.

Further, as described above, the trickle developer transport path 200 and the residual toner transport path 210 are formed so as to be connected to the discharged developer transport path 87, and the discharged developer transport path 87 is connected to the shaft portion 48. Thus, even if the image carrier unit 38a and the developing unit 40a rotate, the position of the discharged developer transport path 87 does not move.
That is, even when the image carrier unit 38a and the developing unit 40a rotate, the position of the connection port for conveying the discharged toner and developer to the recovery path 112 does not move. Therefore, the shape of the recovery path 112 can be reduced.

FIG. 7 shows the image carrier unit 38a and the developing unit 40a when the trickle developer transport path 200 and the residual toner transport path 210 are not formed.
The toner collected by the residual toner collection unit 92 is directly conveyed to the collection path 112 from the residual toner collection port 94.
The trickle developer that has deteriorated in the developing unit 40 a is collected from the trickle developer collection port 220 and directly conveyed to the collection path 112.

In this case, as shown in FIG. 8, when the image carrier unit 38a and the developing unit 40a are rotated from the solid line position to the broken line position, the residual toner collection port 94 and the trickle developer collection port 220 are also rotated in accordance with the rotation. , Move as indicated by arrows A and B.
Since the residual toner collection port 94 and the trickle developer collection port 220 move, the collection path 112 needs to be formed large so as to cover the movement range as shown in FIG. 8, and therefore the collection path 112 is large. Turn into. Further, as the collection path 112 is enlarged, the image forming apparatus 10 is also enlarged.
Since the image forming apparatus 10 according to the embodiment of the present invention has the above-described configuration, the image forming apparatus can be downsized.

Further, in the configuration shown in FIG. 8, since the residual toner collection port 94 moves, it is necessary to form an opening 230 in the collection path 112 according to the movement range. In this case, it is necessary to close the opening 230 so that the toner does not leak outside.
Similarly, since the trickle developer recovery port 220 also moves, it is necessary to form an opening 232 in the recovery path 112 in accordance with the movement range. However, when the developing roll 96 is not rotated, the developer is removed. It is necessary to close the opening 232 so as not to leak outside.
Since the image forming apparatus 10 according to the embodiment of the present invention has the above-described configuration, no opening is formed in the collection path 112, and therefore it is not necessary to close the opening.

In the above-described embodiment, residual toner and trickle developer are respectively transferred from the image carrier unit 38a and the developing unit 40a to the discharged developer transport path 87 by the residual toner transport path 210 and the trickle developer transport path 200. Although it is configured to transport, only the trickle developer transport path 200 may be formed.
In the above-described embodiment, the image carrier unit 38a is configured to rotate about the shaft portion 48, but may not be rotated.

1 is a side view illustrating an outline of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is an enlarged side view showing details of an image carrier unit, a developing unit, and the periphery thereof. FIG. 5 is a diagram illustrating details of a trickle developer conveyance path and a residual toner conveyance path. FIG. 4 is a side view of the image forming apparatus illustrating a transport pipe that transports toner from a toner box to a developing unit. FIG. 3 is a side view of the image forming apparatus showing a recovery path for recovering toner and developer in a developer recovery box. FIG. 6 is a diagram illustrating a state in which the image carrier is separated from the intermediate transfer member and the developing roll is separated from the image carrier. FIG. 6 is a diagram illustrating an image carrier unit and a developing unit when a trickle developer transport path and a residual toner transport path are not formed. FIG. 8 is a diagram illustrating a state in which the image carrier unit and the developing unit illustrated in FIG. 7 are rotated downward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 12 Image forming apparatus main body 14 Main body frame 34 Recessed part 36 Image forming part 38a-38d Image holding | maintenance unit 40a-40d Developing unit 42a-42d LED unit 44 Image holding body 46 Image holding body unit holding member 48 Shaft part 50 Developing unit holding member 56 Intermediate transfer device 58 Intermediate transfer body 86 Cleaning device 87 Discharged developer transport path 90 Blade 92 Residual toner recovery section 94 Residual toner recovery port 96 Developing roll 112 Recovery path 200 Trickle developer transport path 202 Trickle developer recovery Port 210 Residual toner transport path

Claims (5)

An image carrier device supported rotatably about a support shaft ;
A first developer recovery means for recovering the developer remaining on the image carrier of the image carrier device;
Is rotatably supported about the support shaft, and a developing device in which the image holding member to develop the latent image holding,
A second developer collecting means for collecting the developer from the developing device,
The image forming apparatus including the first developer collecting unit and the second developer collecting unit including a common collecting path formed on the support shaft. The first developer recovery means has a first developer transport path connected to a recovery path formed on the support shaft from the image carrier device,
The second developer recovery means has a second developer conveyance path connected to a recovery path formed on the support shaft from the developing device,
The image forming apparatus according to claim 1 , wherein the first developer transport path and the second developer transport path are supported rotatably about the support shaft. The developer recovery means has a developer recovery port formed in the developing device,
3. The image forming apparatus according to claim 1, wherein when the developing device rotates, the developer in the developing device moves, and the developer recovery port moves away from the developer in the developing device. The developing device rotates between a horizontal position and a lower position inclined downward from the horizontal position,
The image forming apparatus according to claim 3 , wherein the developer recovery port is separated from the developer in the developing device when the developing device is rotated to a lower position. A plurality of image carrier devices provided for each color of the developer ;
A first developer recovery means for recovering the developer remaining on the image carrier of the image carrier device;
A developing device that is supported rotatably about a support shaft and that develops a latent image held by the image carrier;
A second developer collecting means for collecting the developer from the developing device,
The image forming apparatus including the first developer collecting unit and the second developer collecting unit including a common collecting path formed on the support shaft.

Images