JP4807215B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, and the like, and in particular, a plurality of paper feeding option cassettes can be stacked and mounted below the main body. The present invention relates to an image forming apparatus configured to convey a recording sheet from an option cassette to an image forming unit through a sheet conveying path.

Conventionally, a plurality of paper feeding option cassettes can be stacked and mounted below the main body, and the recording paper is transported from the option cassette to the image forming unit through the recording paper transport path in the optional cassette and the recording paper transport path in the main body. There is an image forming apparatus configured as described above.
For example, the image forming apparatus disclosed in Patent Document 1 is configured to add option cassettes sequentially in the lower stage from the main body.
A large amount of paper can be fed by adding an optional cassette. Also, different types of recording paper can be selected and used.
JP 2001-192139 A

However, in the prior art, the image forming apparatus has only one pattern for transmitting a driving force for feeding and transporting an optional cassette.
For example, the image forming apparatus of Patent Document 1 has only one pattern of power transmission path for driving all the paper feeding / paper conveying systems of the option cassette by the main motor of the main body. For this reason, there has been a problem that part or all of the paper feeding / paper conveying system of the option cassette does not move when a problem occurs in the motor or parts of the power transmission path. When it is necessary to install a large number of optional cassettes, depending on the product specifications (required price and required accuracy), there is insufficient torque to drive all of the optional cassette paper feed and paper transport systems with only one motor. There is a case. In such a case, an option cassette having a different drive pattern, such as a dedicated independent motor, must be created and replaced, resulting in an increase in cost.
Accordingly, the present invention provides an image forming apparatus configured to form a plurality of drive patterns (power source and power transmission path) for a paper feed / paper transport system of an optional cassette and select an appropriate drive pattern according to convenience. provide.

That is, in claim 1,
A plurality of sheet feeding option cassettes can be stacked and mounted below the main body having the image forming unit, and the image is transferred from the option cassette through the recording paper conveyance path in the option cassette and the recording paper conveyance path in the main body. Configured to transport recording paper to the forming section,
Each option cassette is
A recording paper storage unit;
A pickup roller that feeds the recording paper from the recording paper storage section to a recording paper conveyance path in the option cassette;
A feed roller for conveying recording paper from upstream to downstream along the recording paper conveyance path in the option cassette;
An image forming apparatus comprising:
Provided is an image forming apparatus configured to form a plurality of drive patterns by rearranging a power source and a power transmission path for driving the pickup roller and the feed roller.

  According to a second aspect of the present invention, the power transmission path includes a gear train disposed on a bracket of each option cassette, and each option cassette has a gear attachment portion so that a plurality of paths of the gear train can be formed. Disposed image forming apparatus is provided.

  According to a third aspect of the present invention, there is provided an image forming apparatus having, as the power source, a main body motor provided in the main body and an option cassette motor provided in each option cassette.

  According to a fourth aspect of the present invention, one or more option cassettes for paper feeding can be mounted on the lower side of the apparatus main body having the image forming unit in a state of being vertically stacked. The recording sheet is conveyed from the option cassette to the image forming unit through the recording sheet conveying path in the option cassette and the recording sheet conveying path in the apparatus main body. Each option cassette has a recording paper storage unit, a pickup roller, and a feed roller. A stack of recording paper is stacked in the recording paper storage unit. The pickup roller picks up the recording paper from the recording paper storage unit toward the recording paper conveyance path in the option cassette. The feed roller conveys the recording paper on the recording paper conveyance path of the optional cassette from upstream to downstream. The power source and the transmission path for operating the pickup roller and the feed roller can be freely rearranged, and a plurality of operation patterns can be constructed.

  In claim 5, the transmission path is constructed by only the gears attached to the bracket of each option cassette. The bracket is provided with a plurality of gear attachment parts so that the path of the gear train can be appropriately changed.

  According to a sixth aspect of the present invention, the power source is either a main motor of the apparatus main body or a sub motor of each option cassette.

According to the first aspect of the present invention, when a failure occurs in the paper feeding / paper transport system of the option cassette, it is possible to avoid a state in which some or all of the option cassettes cannot be used by switching to another driving pattern. it can.
In addition, an appropriate drive pattern can be selected and used according to the specifications of the image forming apparatus.

  In claim 2, the power transmission path can be configured flexibly with the option cassette. In addition, there is little transmission loss in the power transmission path.

  According to the third aspect of the present invention, when a problem occurs in the paper feeding / paper transport system of the option cassette, the drive pattern of the pickup roller and the feed roller can be switched to avoid the unusable state of the option cassette. Further, an appropriate power source can be selected and used for driving the pickup roller and the feed roller according to the specifications of the image forming apparatus.

  According to a fourth aspect of the present invention, a plurality of operation patterns (combination of power source and transmission path) of the option cassette paper feed mechanism and paper transport mechanism can be prepared, and a failure occurs in the option cassette paper feed mechanism and paper transport mechanism. The user or service person can rearrange to other operation patterns. This avoids a state in which some or all of the option cassettes cannot be used. In addition, an appropriate operation pattern can be selected in consideration of the component cost and the load on the motor of the apparatus main body.

  According to the fifth aspect of the present invention, the transmission path is freely rearranged in the option cassette. Moreover, since the transmission path is constructed with only gears, there is little power loss.

  According to the sixth aspect of the present invention, the operation patterns of the pickup roller and the feed roller are rearranged when a failure occurs in the paper feeding mechanism and paper transport mechanism of the optional cassette. As a result, the unusable state of the option cassette can be avoided. In addition, an appropriate operation pattern can be selected in consideration of the component cost and the load on the motor of the apparatus main body.

Next, embodiments of the invention will be described.
This embodiment is an example in which the image forming apparatus of the present invention is applied as an electrophotographic printer.
FIG. 1 is a sectional rear view showing the overall configuration of the image forming apparatus of the present invention.
FIG. 2 is a rear view showing a gear that can be attached to the option cassette.
FIG. 3 is a rear view showing a first drive pattern of the option cassette section recording paper conveyance system.
FIG. 4 is a rear view showing a second drive pattern of the option cassette section recording paper conveyance system.
FIG. 5 is a rear view showing a third drive pattern of the option cassette section recording paper conveyance system.

First, an overall configuration outline of the image forming apparatus 1 will be described with reference to FIG.
The image forming apparatus 1 can mount one or more sheet feeding option cassettes 30 on top of each other below the main body 2 having the image forming unit 3 and the sheet feeding main cassette 20. The recording paper 90 is transported from the optional cassette 30 of each stage to the paper discharge tray 7 through the internal recording paper transport path 35 and the recording paper transport paths 5 and 4 in the main body.

The configuration of the main body 2 of the image forming apparatus 1, the recording paper conveyance from the main cassette 20, and the image forming process will be further described.
The main cassette 20 is provided at the bottom of the main body 2 and includes a main cassette mounting portion 29 and a recording paper storage portion 27 that is inserted into the main cassette mounting portion 29 by sliding from the front side of the main body 2.

  In the image forming apparatus main body 2, the main recording paper transport path 4 is formed from the main cassette 20 through the image forming section 3 to the paper discharge tray 7 at the top of the main body 2. 4, a fixing device including a main cassette pickup roller 21, a paper feed sensor (not shown), a registration roller 22, an image forming unit 3, and a heat roller 11 and a pressure roller 17 is arranged in this order in the recording paper conveyance direction. It is installed. These various devices are controlled by a controller provided in the main body 2 and transmitted with power from a main motor (not shown) provided in the main body 2.

  At the bottom of the recording paper storage section 27 of the main cassette 20 is provided a bottom plate 28 on which recording paper bundles 90, 90... Are placed, and when the recording paper storage section 27 is inserted into the main cassette mounting section 29, the bottom plate 28 is provided. The paper feed port side is urged upward by an urging spring (not shown) to rise, and the top end of the recording paper bundle 90, 90... Is pressed against the main cassette pickup roller 21.

  The main cassette pickup roller 21 is provided with a paper feed clutch that transmits or cuts off the drive from the main motor. When the paper feed clutch is connected by a pickup command from the controller, the recording stacked in the paper feed cassette or the like. A sheet of recording paper 90 is picked up from the sheet bundle 90, 90..., And the picked up recording paper 90 is sent out toward the image forming unit 3.

The toner image is transferred to the recording paper 90 sent to the image forming unit 3.
The toner image transfer will be described. First, the surface of the photosensitive drum 16 rotating in a predetermined direction is charged by a charger 15 to which a predetermined bias voltage is applied by a charging bias application circuit. By exposing the surface of the charged photosensitive drum 16 in accordance with image information to be recorded by the laser scanning device 14, the charge on the exposed portion of the surface of the photosensitive drum 16 is removed, and an electrostatic latent image is formed. Is done. A bias voltage is applied to the developing roller 13, the supply roller (not shown), and the blade (not shown) by a developing device bias application circuit, and the developing roller 13 and the supply roller rotate while being pressed against each other. And the toner is carried on the surface of the developing roller 13. The thickness of the toner on the surface of the developing roller 13 is regulated to one or two layers by a blade, and when the toner layer comes into contact with the electrostatic latent image, the toner is attracted to the electrostatic latent image to be visualized as a toner image. Then, a toner image is carried on the surface of the photosensitive drum 16. The toner image is transferred onto the recording paper 90 passing through the pressure contact portion between the photosensitive drum 16 and the transfer roller 12 by the transfer roller 12 to which a bias voltage having a polarity opposite to the toner charging polarity is applied by the transfer bias applying circuit. Transcribed. The toner remaining on the surface of the photosensitive drum 16 after the transfer of the toner image is collected by the eraser brush 18.

The recording paper 90 onto which the toner image has been transferred by the image forming unit 3 further passes through a fixing device including a heat roller 11 and a pressure roller 17, and at this time, heat and pressure are respectively applied by the heat roller 11 and the pressure roller 17. Thus, the toner image is fixed on the recording paper 90. Then, the recording paper 90 is discharged to the paper discharge tray 7.
All of these series of operations are performed by issuing an operation / stop command to the image forming unit 3, the heat roller 11 and the like at a predetermined timing by the controller.

Next, the configuration of the option cassette 30 and its paper feed / paper drive conveyance system will be described.
As shown in FIG. 1, in this embodiment, for example, optional cassettes 30, 30, and 30 are mounted in three stages below the main body 2. In other words, the image forming apparatus 1 includes a four-stage paper feeding cassette together with the main cassette 20 in the main body 2. In this specification, the main cassette 20 is the first stage paper feed cassette, the uppermost option cassette 30 is the second stage option cassette 30, the next stage option cassette 30 is the third stage option cassette 30, and the lowermost stage. The option cassette 30 is expressed as the fourth-stage option cassette 30.

The option cassette 30 includes a box-shaped cassette housing 39 and a recording paper storage unit 38 that can be inserted into and removed from the cassette housing 39 from the front.
In the option cassette 30, there is formed an option cassette recording paper transport path 35 that vertically penetrates the entire cassette housing 39 and the recording paper storage section 38.

Each option cassette 30 picks up the recording paper 90 from the recording paper storage section 38 one by one and feeds it to the option cassette recording paper conveyance path 35, and from the upstream along the option cassette recording paper conveyance path 35. A feed roller 32 that relays and conveys the recording paper 90 downstream and an optional cassette motor 70 are provided.
A pickup transport path 34 is formed between the recording paper storage unit 38 and the optional cassette transport path 35. The pickup conveyance path 34 joins the substantially upper end portion of the option cassette recording sheet conveyance path 35, and the recording sheet 90 picked up by the pickup roller 31 is sent out to the option cassette conveyance path 35 via the pickup conveyance path 34.
The feed roller 32 is provided in the middle of the option cassette recording paper conveyance path 35 on the upstream side from the junction with the pickup conveyance path 34, and is conveyed from the option cassette 30 (upstream) mounted on the lower stage. The recording paper 90 is relayed and conveyed downstream.

Inside the main body 2, there is formed an optional cassette connection recording paper conveyance path 5 that connects the recording paper conveyance path 35 of the second-stage option cassette 30 to the main recording paper conveyance path 4 of the main body 2. A main body side feed roller 26 that relays the recording paper 90 conveyed from the second-stage option cassette 30 is provided in the middle of the lower end of the recording paper conveyance path 5 for connecting the optional cassette. The main body side feed roller 26 is driven by the main motor of the main body 2.
For example, when paper is fed from the fourth-stage option cassette 30, the third-stage option cassette 30 and then the second-stage option cassettes 30 and 30 are sequentially transported downstream by the feed rollers 32 and 32, and the main body 2 option is supplied. The recording paper transport path 5 for cassette connection is entered, and further relayed and transported to the main recording paper transport path 4 by the main body side feed roller 26.

Next, the drive pattern of the paper feed / paper transport system of the option cassette 30 will be described.
In the present application, the drive pattern is a combination of a power source for driving the pickup roller 31 and the feed roller 32 of each option cassette 30 and a power transmission path from the power source.
As will be described later, the present embodiment has a main motor (main body motor) of the main body 2 and an optional cassette motor 70 included in each option cassette as a power source, and is configured to form a total of three types of drive patterns. ing.
In the first drive pattern, the pickup roller 31 and the feed roller 32 of each option cassette 30 are all driven by the main motor of the main body 2. In the second drive pattern, the main motor is not used, and the pickup roller 31 and the feed roller 32 of each option cassette 30 are all driven by the option cassette motor 70. In the third drive pattern, the pickup roller of each option cassette 30 is driven by the option cassette motor 70, while the feed roller is driven by the main motor of the main body 2.

Here, as will be described later, in the image forming apparatus 1, the drive pattern of the paper feed / paper transport system of the option cassette 30 can be switched simply by changing the gear at the bracket 100. Therefore, for example, while the image forming apparatus 1 is being used in the first drive pattern in which all the paper feed / paper transport systems of the option cassette 30 are driven by the main motor of the main body 2, the transmission mechanism for connecting the option cassette is used. When a failure occurs, it is possible to avoid the unusable state of the option cassette 30 by simply switching to the second drive pattern that does not use the main motor. Further, if the option cassette motor 70 fails while the image forming apparatus 1 is being used in the second drive pattern or the third drive pattern using the option cassette motor 70, only the main motor is used. By switching to the first drive pattern, the unusable state of the option cassette 30 can be avoided.
In addition, if an excessive load exceeding the specification is applied to the main motor of the main body 2 by adding an optional cassette while using the first drive pattern, switch to the second drive pattern, for example. Thus, an optional cassette can be added without increasing the load on the main motor. In addition, in the second drive pattern, as the number of option cassettes 30 to be added increases, there may be a problem that the noise of the option cassette motor 70 increases and the power consumption as a whole increases. In such a case, if the third drive pattern is used, only one optional cassette motor 70 is used together with the main motor, so noise can be reduced and overall power consumption can be suppressed. it can.

  As shown in FIG. 2A, a bracket 100 is provided on the back side of the option cassette 30, and a pickup roller driving gear 54 and a feed roller driving gear 62 are provided on the bracket 100. The pickup roller driving gear 54 is provided at the end of the rotation shaft 31a of the pickup roller 31 (see FIG. 1) so as not to be relatively rotatable. The feed roller drive gear 62 is provided at the end of the rotation shaft 32a of the feed roller 32 (see FIG. 1) so as not to be relatively rotatable.

  A plurality of studs (gear mounting shafts) for mounting and holding a gear train that transmits power to the pickup roller driving gear 54 and the feed roller driving gear 62 are arranged on the bracket 100. In the image forming apparatus 1, three types of drive patterns (gear train patterns) can be configured by changing the combination of gears to be mounted. FIG. 2B shows a state where gears are attached to all studs. Of these, only necessary gears can be mounted to switch the drive pattern. However, to prevent two patterns of gear trains from being created at the same time, some gears must interfere with gears in other gear trains so that gears in different gear trains cannot be inserted simultaneously. Is desirable.

First, the first drive pattern will be described with reference to FIG.
In this drive pattern, the pickup roller 31 and the feed roller 32 of each option cassette 30 are all driven by the main motor (main body motor) of the main body 2. The main body 2 is provided with an option cassette connecting transmission mechanism for transmitting power from the main motor to the option cassette side, and an output gear 19 is provided at the end thereof.

  A first connection gear 51 is disposed at the upper end of each bracket 100. A second connection gear 58 is arranged at the lower end. In a state where the option cassettes 30 and 30 are stacked one above the other, the second connection gear 58 of the upper option cassette 30 and the first connection gear 51 of the lower option cassette 30 are engaged with each other. In the second-stage option cassette 30, the first connecting gear 51 meshes with the output gear 19 at the end of the option cassette connecting transmission mechanism of the main body 2.

  Here, the first connecting gear 51 is supported by an arm 101 that can swing around the axis of the idle gear 52, and the arm 101 and the cassette housing 39 are connected via a spring 102. By this spring 102, the first connecting gear 51 is urged toward the second connecting gear 58 or the output gear 19, and the two are reliably engaged with each other, so that power transmission is appropriately performed.

In each option cassette 30, the pickup roller drive gear 54 is drivingly connected to the first connection gear 51 of the option cassette 30 in the same stage via a gear 53 and a gear 52. The feed roller drive gear 62 is also drive-connected to the first connecting gear 51 via gears 57 d, 57 c, 57 b, 57 a, gear 56, gears 55 b, 55 a, and gear 52. The first connection gear 51 is drivingly connected to the second connection gear 58 of the same-stage option cassette 30 via the gear 52, gears 55 a and 55 b, and the gear 56.
When the optional cassettes 30, 30, and 30 are mounted on the main body 2, all the pickup rollers 31, 31, and 31 and the feed rollers 32, 32, and 32 of the optional cassettes 30, 30, and 30 are driven by the main motor of the main body 2. Connected.

In this drive pattern, the option cassette motor 70 used in the second and third drive patterns described later is not used. Therefore, the option cassette motor 70 is removed. Further, the gears 59, 60 and 61 (see FIG. 2B) for transmitting the power of the option cassette motor 70 are not used.
In the figure, the power transmission path is indicated by an arrow on the gear train.

With reference to FIGS. 1 and 3, for example, a sheet feeding operation from the fourth-stage option cassette 30 will be described.
Like the main cassette 20, a plate-like bottom plate 37 on which recording paper bundles 90, 90... Are placed is provided at the bottom of the recording paper storage section 38 of the optional cassette 30. When attached to the body 39, the paper feed port side of the bottom plate 37 is urged upward by a spring (not shown) and raised, and the top end of the recording paper bundle is pressed against the pickup roller 31.

  The pickup roller drive gear 54 is provided with a paper feed clutch 54a. As for the sheet feeding clutch 54a, only the connection of the option cassette 30 of the fourth stage selected for sheet feeding is controlled by the command of the controller, and the sheet feeding clutch 54a of the other option cassette 30 and the sheet feeding clutch of the main cassette 20 are controlled. Is cut off. As a result, only the fourth-stage option cassette 30 is driven with the rotation shaft 31 a connected to the pickup roller drive gear 54, and the recording paper 90 is fed from the recording paper storage unit 38 to the pickup conveyance path 34 by the pickup roller 31.

The recording sheet 90 enters the option cassette recording sheet conveying path 35 from the pickup conveying path 34 at the junction, and is further conveyed to the option cassette recording sheet conveying path 35 of the second-stage option cassette 30. Then, it is further relayed and conveyed to the main body 2 side (downstream) by the feed roller 32 of the second-stage option cassette 30.
The recording paper 90 enters the option cassette connecting recording paper conveyance path 5 of the main body 2 from the option cassette recording paper conveyance path 35 of the second-stage option cassette 30. Then, it is further relayed by the main body side feed roller 26 in the middle of the transport path 5, enters the main recording paper transport path 4, and is transported to the image forming unit 3. The subsequent operations from the image forming process to paper discharge are the same as those in the case of paper feed from the main cassette 20 described above.

Next, the second drive pattern will be described with reference to FIG.
In this drive pattern, the pickup roller 31 of the option cassette 30 in each stage is driven by the option cassette motor 70 provided in the option cassette 30 in the same stage. On the other hand, the feed roller 32 of the option cassette 30 in each stage is driven by an option cassette motor 70 provided in the option cassette 30 adjacent to the lower stage. The main motor of the main body 2 is not used for driving the pickup roller 31 and the feed roller 32.

  The optional cassette motor 70 is attached to the opposite side of the gear train group of the bracket 100. The motor output shaft 71 of the option cassette motor 70 protrudes through the support plate 100 toward the gear train group side, and an output gear 72 is provided at the end of the motor output shaft 71 so as not to be relatively rotatable.

  The pickup roller drive gear 54 of each option cassette 30 is drivingly connected to an optional cassette motor 70 in the same stage via gears 59 and 61 and a motor output gear 72. That is, for example, the pickup roller 31 of the third-stage option cassette 30 is driven by the option cassette motor 70 of the same third-stage option cassette 30.

  On the other hand, the feed roller drive gear 62 of each option cassette 30 with the option cassettes 30 mounted in an overlapping manner is further provided with a lower option via the gears 57d, 57c, 57b and 57a, the gear 56, and the second connecting gear 58. The first connection gear 51 of the cassette 30, the gears 52, 60, 61, and the motor output gear 72 are drivingly connected to the option cassette motor 70 of the lower option cassette 30. That is, for example, the feed roller 32 of the third-stage option cassette 30 is driven by the option cassette motor 70 of the fourth-stage option cassette 30.

In this drive pattern, the motor output gear 72, the gears 61 and 60, the gear 52, and the first connecting gear 51 constitute an output transmission mechanism that outputs the power of the option cassette motor 70 to the upper option cassette 30. In addition, the second transmission gear 58, the gear 56, the gears 57a, 57b, 57c and 57d, and the feed roller drive gear 62 constitute an input transmission mechanism for transmitting the power input from the lower option cassette 30 to the feed roller 32. ing. By connecting the lower output transmission mechanism and the upper input transmission mechanism, a feed roller transmission mechanism is formed.
In this drive pattern, the gear 55a (see FIG. 2B) is not used, so that the output transmission mechanism and the input transmission mechanism of the feed roller transmission mechanism are independent on the bracket 100 of each option cassette 30. ing. Instead of not using the gear 55a, the gear 55b or the gears 55a and 55b may not be used.
In this drive pattern, the gear 53 (see FIG. 2B) is not used.

Since it is not necessary to transmit power between the main body 2 and the second-stage option cassette 30, only the second-stage option cassette 30 has the gear 60 removed and meshes with the output gear 19 of the main body 2. The power of the option cassette motor 70 is not transmitted to the first connection gear 51.
In the figure, the power transmission path is indicated by an arrow on the gear train.

With reference to FIGS. 1 and 4, for example, the operation of the drive mechanism when paper is fed from the fourth-stage option cassette 30 will be described.
In response to a command from the controller of the main body 2, the option cassette motors 70 and 70 of the third and fourth option cassettes 30 and 30 except the second stage are driven. At the same time, the paper feed clutch 54 a of the fourth-stage option cassette 30 is connected, and the recording paper 90 is fed out to the recording paper conveyance path 35 via the pickup conveyance path 34. The recording paper 90 is relayed to the feed rollers 32 and 32 of the third-stage option cassette 30 and then the second-stage option cassette 30 and then conveyed into the main body 2. Here, the feed roller 32 of the third-stage option cassette 30 is driven by the motor 70 of the fourth-stage option cassette. The feed roller 32 of the second-stage option cassette 30 is driven by the motor 70 of the third-stage option cassette 30.
Subsequent operations are the same as those in the first drive pattern, and thus description thereof is omitted.

As described above, when paper is fed from the option cassette 30 of the third stage or lower, it is not necessary to use the option cassette motor 70 of the second stage option cassette 30. It is only necessary to drive the motor 70 up to the option cassette 30 selected for paper feed.
When paper is fed from the second-stage option cassette 30 adjacent to the main body 2, only the pickup roller 31 of the second-stage option cassette 30 needs to be driven to rotate on the option cassette side. Since there is no need to use the feed roller 32, only the second optional cassette motor 70 is used.

Next, the third drive pattern will be described with reference to FIG.
In this drive pattern, the pickup rollers 31 of the option cassettes 30 of each stage are driven by the option cassette motor 70 provided in the option cassette 30 of the same stage, while the feed rollers 32 are all driven by the main motor of the main body 2.

  The pickup roller drive gear 54 of each option cassette 30 is drivingly connected to the option cassette motor 70 of the same stage via gears 59 and 61 and a motor output gear 72 as in the second drive pattern. That is, for example, the pickup roller 31 of the third-stage option cassette 30 is driven by the option cassette motor 70 of the same third-stage option cassette 30.

  On the other hand, the feed roller drive gear 62 is drivingly connected to the first connecting gear 51 through the gears 57d, 57c, 57b, and 57a, the gear 56, the gears 55b and 55a, and the gear 52 similarly to the first driving pattern. ing. The first connection gear 51 is drivingly connected to the second connection gear 58 of the same stage option cassette 30 via a gear 52, gears 55 a and 55 b, and a gear 56. As a result, all the feed rollers 32, 32, and 32 of the option cassettes 30, 30, and 30 are drivingly connected to the main motor of the main body 2 in a state where the option cassettes 30, 30, and 30 are mounted on the body 2 in an overlapping manner .

As described above, in this drive pattern, the feed rollers 32 of all option cassettes 30 are driven by the main motor of the main body 2. Further, since the option cassette motor 70 is used to drive only the pickup roller 31 of the option cassette 30 selected for paper feed, only the motor 70 of the option cassette 30 selected for paper feed may be used.
In this drive pattern, the gear 53 and the gear 60 are not mounted.
In the figure, the power transmission path is indicated by an arrow on the gear train.

The embodiment of the image forming apparatus of the present invention has been described above.
The gear train pattern of each option cassette 30 is not limited to the pattern shown in this embodiment. What is necessary is just to comprise the optimal gear train pattern according to the dimension of the option cassette 30, the arrangement | positioning of the pick-up roller 31, the feed roller 32, etc.

  In addition, the paper feeding / paper conveying system of the option cassette 30 may be configured such that a plurality of power transmission paths from one power source to the pickup roller 31 or the feed roller 32 can be formed. For example, studs may be arranged so that a plurality of gear train paths from the optional cassette motor 70 can be formed on the bracket 100.

  Further, although the transmission mechanism of the paper feed / paper transport system of the option cassette 30 is configured by a gear train, a part or all of the transmission mechanism can be configured by another transmission mechanism such as a belt transmission mechanism.

  Further, the image forming apparatus 1 of the present invention is not limited to a printer, and can be generally applied to a copying machine, a facsimile machine, or a multifunction machine having both a copying function and a facsimile function. The image forming unit 3 is not limited to an electrophotographic type, and may be of any type such as an inkjet type.

  The embodiment of the image forming apparatus according to the present invention has been described above. It will be readily understood by those skilled in the art that the image forming apparatus according to the present invention is not limited to the configuration described above, and can be freely configured based on the idea that characterizes the present invention.

  The image forming apparatus of the present invention can be applied universally as a copying machine, a facsimile, a printer or the like in which an option cassette can be mounted.

1 is a cross-sectional rear view illustrating an overall configuration of an image forming apparatus according to the present invention. The rear view which showed the gear which can be mounted | worn with an option cassette. The rear view which showed the 1st drive pattern of the option cassette part recording paper conveyance system. The rear view which showed the 2nd drive pattern of the option cassette part recording paper conveyance system. The rear view which showed the 3rd drive pattern of the option cassette part recording paper conveyance system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body 3 Image formation part 4 Main recording paper conveyance path 5 Recording paper conveyance path for option cassette connection 19 Output gear 20 Main cassette 26 Main body side feed roller 30 Option cassette 31 Pickup roller 32 Feed roller 34 Pickup conveyance path 35 Optional cassette recording paper transport path 70 Optional cassette motor 100 Bracket

Claims (6)

A plurality of sheet feeding option cassettes can be stacked and mounted below the main body having the image forming unit, and the image is transferred from the option cassette through the recording paper conveyance path in the option cassette and the recording paper conveyance path in the main body. Configured to transport recording paper to the forming section,
Each option cassette is
A recording paper storage unit;
A pickup roller that feeds the recording paper from the recording paper storage section to a recording paper conveyance path in the option cassette;
A feed roller for conveying recording paper from upstream to downstream along the recording paper conveyance path in the option cassette;
An image forming apparatus comprising:
An image forming apparatus configured to form a plurality of drive patterns by rearranging a power source and a power transmission path for driving the pickup roller and the feed roller.   The power transmission path is configured by a gear train disposed on a bracket of each option cassette, and a gear mounting portion is disposed on each option cassette so that a plurality of paths of the gear train can be formed. The image forming apparatus according to 1.   The image forming apparatus according to claim 1, further comprising: a main body motor provided in the main body and an option cassette motor provided in each option cassette as the power source. An apparatus main body having an image forming unit and a recording paper conveyance path;
An image forming apparatus having one or more option cassettes, which are mounted in a state of being vertically stacked on the lower side of the apparatus main body,
Each optional cassette has a recording paper conveyance path, a recording paper storage section, a pickup roller and a feed roller,
The recording paper storage unit stacks recording paper bundles, the pickup roller picks up the recording paper from the recording paper storage unit toward the recording paper conveyance path of the optional cassette, and the feed roller records the recording paper in the recording paper conveyance path of the optional cassette. Transport from upstream to downstream,
An image forming apparatus in which a power source and a transmission path for operating a pickup roller and a feed roller can be freely recombined.   5. The image forming apparatus according to claim 4, wherein each option cassette has a bracket provided with a plurality of gear mounting portions, and the transmission path is constructed only by a gear attached to the bracket of each option cassette.   The image forming apparatus according to claim 4, wherein the power source is one of a main motor provided in the apparatus main body and a sub motor provided in the option cassette.

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