JPH07295439A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device capable of the correct supply of toner by providing a cut-off means for cutting off a driving part and an image forming part from each other at the action time of double-side image forming mechanism, and controlling a toner supply means and the cut-off means. CONSTITUTION:An engine control part monitors a detection signal from a paper discharge sensor 49 and confirms the passage of a sheet near a sheet discharge port 12. After the sheet is fed into a double side machine 43 from a discharge roller 29, the engine control part stops the double side machine 43 and puts a cut-off clutch off to cut off a driving part and the image forming part from each other. At the time of cutting off the driving part and the image forming part from each other, the driving part and the image forming part are cut off unless the supply of toner is in progress. In the case of the supply of toner being in progress, the driving part and the image forming part are cut off upon the termination of toner supply, so that toner can be supplied correctly even if the driving part and the image forming part are cut off from each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a plurality of functions such as an image forming function, a document reading function, a double-sided printing function, etc., and having a separating means for separating an image forming portion from a driving portion.

[0002]

2. Description of the Related Art An image forming apparatus for forming an image on an image carrier and transferring the image onto a transfer material is disclosed in Japanese Patent Application Laid-Open No. 2-150869.
It is known from Japanese Patent Laid-Open Publication No. Hei 3-184061 and the like. In addition, a multifunction machine having a plurality of functions such as a copying machine, a printer, and a facsimile has been proposed. Some of the multifunction machines have a separating means for separating the image forming section from the driving section and a double-sided printing function.

In the multi-function machine having the separating means and the double-sided printing function, at the time of image formation, the sheet conveying path and the image forming section are driven in the forward direction by the driving section, and the sheet is conveyed by the sheet conveying path to form the image forming section. After the image is transferred on one side, the sheet is discharged from the sheet discharge port. During double-sided printing, first, the paper transport path and the image forming unit are driven in the forward direction by the drive unit, the paper is transported by the paper transport path, and the image is transferred on one side by the image forming unit.

Next, the driving section is separated from the sheet conveying path and the image forming section by the separating means, and the driving section reversely drives the double-sided image forming mechanism. The double-sided image forming mechanism returns the sheet on which an image is formed on one side to the state before the image forming section, and again the sheet conveying path and the driving section are connected to the driving section so that the sheet conveying path and the image forming section are driven in the forward direction by the driving section. Driven to. Then, the sheet is conveyed by the sheet conveying path, the image is transferred to the other surface in the image forming unit, and then the sheet is discharged from the sheet discharge port.

The image forming unit rotates an image carrier made of a photoconductor and uniformly charges it by a charging device, and then forms an electrostatic latent image on the photoconductor by image exposure, and the electrostatic latent image is formed by a developing device. It is developed with a developer containing toner and transferred to a sheet by a transfer device. The developing device consumes toner by developing the electrostatic latent image, and the toner is replenished to the developer from the toner replenishing portion. The toner replenishing section works together with the image forming section.

[0006]

In a multifunction machine having the above-mentioned separating means and double-sided printing function, during double-sided printing, the drive section is separated from the sheet conveying path and the image forming section by the separating section after the one-sided image formation of the sheet and is reversed. Drive the double-sided image forming mechanism, and the toner replenishing unit is interlocked with the image forming unit by the driving unit.Therefore, the driving unit disconnects the sheet conveying path and the image forming unit by the detaching means during toner replenishment of the toner replenishing unit. If the toner is replenished, the toner replenishing unit will not replenish the toner, and the toner will not be replenished accurately.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus which solves the above problems and can replenish toner accurately.

[0008]

In order to achieve the above object, the invention according to claim 1 has a sheet conveying path for conveying a sheet and discharging it from a sheet discharge port, and a toner replenishing section for replenishing toner. An image forming unit that forms an image on a sheet conveyed by the sheet conveying path, an original conveying path that shares a part with the sheet conveying path and conveys an original and discharges the original from an original discharge port, and the original. A document reading unit that reads an image from a document transported by a transport path; a double-sided image forming mechanism that sends a sheet having an image formed on one side by the image forming unit from the document discharge port to the document transport path;
It is used to drive the toner replenishing means, drives the image forming section in the forward direction to form an image on one side of the sheet, and further drives the double sided image forming mechanism to form the sheet on which the single sided image is formed. A drive unit for driving the image forming unit in the forward direction to form an image on the other surface of the paper after returning to the paper transport path via the double-sided image forming mechanism and a part of the document transport path; Switching the transport path between the paper discharge port side and the double-sided image forming mechanism side, and switching the common part of the paper transport path and the document transport path between the paper transport path side and the document transport path side And a disconnecting unit that disconnects the drive unit and the image forming unit when the double-sided image forming mechanism operates.
In the image forming apparatus in which the toner replenishing unit is interlocked with the image forming unit, a control unit for controlling the toner replenishing unit and the separating unit is provided.

According to a second aspect of the invention, in the image forming apparatus according to the first aspect, the toner replenishing means replenishes the toner when the control means causes the separating means to separate the drive section and the image forming section from each other. In the case where it is being carried out, after waiting for the toner replenishment of the toner replenishing means to be completed, the separating means is made to separate the drive section and the image forming section.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the control unit causes the toner replenishing unit to replenish the toner when the separating unit separates the drive unit from the image forming unit. When the toner replenishment time of the toner replenishment means is stored in the storage means, the toner replenishment of the toner replenishment means is stopped, and the drive section and the image formation are performed to form an image on the other surface of the sheet. The toner replenishment section is made to replenish the toner for the remaining toner replenishment time stored in the storage means when the toner replenishment section is connected.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the drive section and the image forming section are connected to each other when the other surface image of the sheet is formed, and the toner replenishing section is stored in the storage means. After the toner is replenished for the stored remaining toner replenishment time, the image formation on the other surface of the sheet is started.

According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, the control means supplies the toner for the remaining toner supply time stored in the storage means by the toner supply section to other sheets. After the surface image formation is completed, it is performed together with the toner replenishment by the other surface image formation of the sheet.

According to a sixth aspect of the present invention, in the image forming apparatus according to the third aspect, the storage means is a non-volatile storage means.

[0014]

According to the first aspect of the invention, the sheet is conveyed by the sheet conveying path and discharged from the sheet discharge port, and the image forming section forms an image on the sheet conveyed by the sheet conveying path. The document is transported by the document transport path and discharged from the document discharge port, and the document reading unit reads an image from the document transported by the document transport path. The drive unit is used to drive the toner replenishing means, drives the image forming unit in the forward direction to form an image on one side of the sheet, and further drives the double-sided image forming mechanism to remove the sheet after the one-sided image formation. After returning to the paper transport path via the double-sided image forming mechanism and a part of the document transport path, the image forming unit is driven in the forward direction to form an image on the other surface of the paper. The switching means switches the paper transport path between the paper discharge port side and the double-sided image forming mechanism side, and
The common part of the paper transport path and the document transport path is switched between the paper transport path side and the document transport path side. The disconnecting unit disconnects the drive unit and the image forming unit during the operation of the double-sided image forming mechanism, and the toner replenishing unit works in conjunction with the image forming unit. Then, the toner replenishing means and the separating means are controlled by the control means.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, when the control unit causes the separating unit to separate the drive unit and the image forming unit, the toner replenishing unit replenishes the toner. After the toner replenishment of the toner replenishing unit is completed, the separating unit is caused to separate the drive unit and the image forming unit.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the control means supplies the toner by the toner replenishing means when the separating means separates the drive section and the image forming section from each other. Stores the remaining toner replenishment time of the toner replenishment means in the storage means, stops the toner replenishment of the toner replenishment means, and stores the means when the drive unit and the image forming unit are connected to form an image on the other surface of the sheet. The toner replenishing section is made to replenish the toner for the remaining toner replenishment time stored in.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the drive unit and the image forming unit are connected to each other during image formation on the other surface of the sheet, and the toner replenishing unit is stored in the storage means. After the toner is supplied for the remaining toner supply time, the image formation on the other surface of the paper is started.

According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, the control unit causes the toner replenishment unit to replenish the toner for the remaining toner replenishment time stored in the storage unit, and form the other surface image of the sheet. After the end, it is performed together with toner supply by image formation on the other surface of the paper.

According to a sixth aspect of the present invention, in the image forming apparatus according to the third aspect, the storage means which is a non-volatile storage means stores the remaining toner supply time of the toner supply means.

[0020]

FIG. 2 shows a first embodiment of the present invention. This embodiment is an embodiment of the invention described in claims 1 and 2, and a sheet (from the cassette sheet feeding device 11 or an optional detachable manual sheet feeding device 15 to a sheet discharging unit 13 through a sheet discharging port 12). Transfer sheet), a sheet conveyance path for conveying an image, an image forming unit for forming an image and transferring the image on the sheet, a fixing device 14 for fixing the image on the sheet, and a manual sheet feeding device 15 via a document discharge port 16 And a reading sensor 18 including a CCD as an image reading unit for reading the content of the document.
And a structure and an electrical component for holding and controlling them. Part of the paper transport path and the original transport path are common.

At the time of image formation, the sheet conveying path and the image forming section are driven in the forward direction by a drive section composed of a main motor. In the normal mode, the paper 19 is fed from the cassette paper feeding device 11 and conveyed to the registration roller 20, and the registration sensor 21 detects the leading end of the paper 19 to stop the conveyance of the paper and the leading end of the paper. Is added to the registration roller 20.

In the image forming unit, the image carrier 22 made of a drum-shaped photoconductor is rotationally driven in the counterclockwise direction by the drive unit so that the surface thereof is uniformly charged by the charging charger 23 as the charging unit, and then the unit serves as the exposure unit. Laser optical system 24
An electrostatic latent image is formed by imagewise exposure by, and is developed by the developing device 25 to form a toner image. In this case, the laser optical system 24 irradiates the drum-shaped photoconductor 22 with laser light whose intensity is changed according to the raster data by the semiconductor laser being modulated and driven by the modulation driving unit by the input raster data.

The toner image on the drum-shaped photosensitive member 22 is transferred to the registration roller 2 by the transfer means 26 including a transfer charger.
It is transferred to the lower surface of the paper from 0. Drum-shaped photoconductor 22
After the transfer of the toner image, the cleaning device 27 cleans the residual toner to remove the residual toner, and the removed toner is recovered and stored in a recovery tank 28. The sheet on which the toner image has been transferred has the toner image fixed by the fixing device 14, and is ejected as a print from the paper ejection port 12 to the paper ejection unit 13 by the paper ejection roller 29.

In the manual paper feeding mode, instead of the paper 19 being fed from the cassette paper feeding device 11, the paper is fed by the manual paper feeding device 15 and conveyed to the registration roller 20, and the registration sensor 21 causes the paper 19 to be fed. By detecting the leading edge of the sheet, the conveyance of the sheet is stopped and the leading edge of the sheet is gripped by the registration roller 20. The other operations are the same as those in the normal mode.

The developing device 25 has a developing section 25a and a toner replenishing section 25b. In the developing section 25a, the developing roller 30 and the agitator 31 are driven by a developing motor to circulate the developer to the drum-shaped photoconductor 22. By being supplied, the electrostatic latent image on the drum-shaped photoconductor 22 is developed. Toner supply unit 2
Reference numeral 5b is interlocked with the image forming section, and when the toner replenishing clutch is turned on, the agitator 32 is rotationally driven by the main motor to replenish the toner in the toner tank 33 to the developer in the developing section 25a.

At the time of image reading, the sheet conveying path and the image forming section are driven in the forward direction by the driving section composed of the main motor, and the sheet original 34 is fed by the manual sheet feeder 15 and conveyed to the reading timing roller 35. When the scan timing sensor 36 detects the leading edge of the original 34, the feeding of the original 34 is stopped and the leading edge of the original is gripped by the reading timing roller 35.
The reading timing roller 35 sends out the original at a timing, the original is conveyed along the original conveying path, and the reading sensor 18 reads the image from the original 34 passing above.

The branching guide 37, which is a branching claw, is installed at a portion where the document transport path and the paper transport path branch from the common portion to switch the transport path of the document or the paper, and is controlled by the engine control unit 40 described later. . At the time of image formation, the branch claw 37 is switched to the side of the paper transport path, and the paper is transported along the paper transport path. At the time of reading an image, the branch claw 37 is switched to the document transport path side, and the document 34 is transported along the document transport path and discharged from the document discharge port 16 to the paper discharge unit 17.

FIG. 1 shows the electrical components of this embodiment. This electrical component part has a host 38 which is an information processing device that also has a user interface, and peripheral devices 39 to 47 which are input / output parts of the host 38. The host 38 has a display 21b and a keyboard 21c, and RS-2.
It is connected to the outside through 32C. Peripheral aircraft 39-47
Is a controller 39, an engine control unit 40, a scanner unit 41, a printer unit 42, an optional manual paper feeder 15, a duplexer 43, an operation panel 44, an IC card 45,
The storage device 46 includes a magnetic disk device and the facsimile interface 47.

The controller 39 has an image memory 22b and a font memory 22c, and is connected to the host 38 via bidirectional Centronics. The printer unit 42 is
In this embodiment, a mechanism for producing a print, a drive motor such as a main motor and a developing motor, various clutches including a toner replenishing clutch, various solenoids (SOL) for respectively driving branch guides 37, 48, and the like are engine-controlled. The print is created as described above by being drive-controlled by the unit 40, various sensors perform various detections, and the detection signals are output to the engine control unit 40.

The drive unit composed of the main motor is adapted to be disconnected or connected to the image forming unit by a disconnecting means, for example, a disconnecting clutch, and the disconnecting clutch is controlled by the engine control unit 40. Further, the engine control unit 40 controls the toner replenishment clutch so that the developing ability of the developing unit 25a becomes constant based on the detection signal from the sensor that detects the developing ability of the developing unit 25a, and replenishes the toner to the toner replenishing unit 25b. To perform.

The scanner section 41 is a mechanism used only for reading the original image in this embodiment, and is driven by the engine control section 40 to read the image from the original and read from the reading sensor 18 as described above. The image data is sent to the controller 39. The printer unit 42 includes a sheet conveyance path, and the scanner unit 41 includes a document conveyance path. The operation panel 44 is for performing simple operations such as start and reset in this embodiment, and the IC card 4
Reference numeral 5 is provided as an additional memory for adding programs and fonts. Facsimile interface 4
7 is connected to the outside through a communication line.

At the time of image formation, the information processed for printing by the host 38 is information such as text and bitmap, which is sent to the controller 39. The controller 39 uses the font information in the font memory 22c and the IC memory 45 and the internal function to generate raster data on the image memory 22b according to the printing information from the host 38. The raster data including the operation instructions from the host 38 and the controller 39 is sent by the controller 39 to the engine control unit 40.

The engine control unit 40 has a printer unit 41, according to operation instructions from the host 38 and the controller 39.
By controlling the manual sheet feeding device 15 and inputting the raster data from the controller 39 to the laser optical system 24, an image corresponding to the raster data is formed in the image forming section, thereby making a print as described above. In this case, the paper is
In the normal mode, the sheet is fed from the cassette sheet feeding device 11 and conveyed, and in the manual sheet feeding mode, the sheet is fed and conveyed by the manual sheet feeding device 15.

At the time of image reading, when an image reading request from the host 38 is sent to the engine control unit 40 via the controller 39, the engine control unit 40 causes one of the scanner unit 41 and printer unit 42 necessary for reading the original. The document feeding unit 15 is controlled so that the document is conveyed. The image data read from the scanner unit 41 is once buffered by the controller 39 and then sent to the host 38.

During facsimile communication, the paper transport path and the image forming section are driven in the forward direction by a drive section composed of a main motor. At the time of facsimile transmission, the telephone number information of the other party is sent from the host 38 to the facsimile interface 47 via the controller 39, and in response to this, the controller 39 issues an image capture request to the engine control unit 40 for the image to be transmitted, and the scanner is issued. The image information of the transmission original is fetched from the section 41 and sent to the facsimile interface 47. The facsimile interface 47 calls the other party by using the communication line according to the telephone number information of the other party from the controller 39, compresses the image information by MH, MR or the like and transmits it to the other party through the communication line. It should be noted that the image information of the transmission document is the host 38
In the case of internal image information from the storage device 46, the controller 39 does not take in the image information from the scanner unit 41.

When receiving a facsimile, the received image information is printed immediately and the received image information is stored in the storage device 4.
It is divided into the case of storing in 6. When printing the received image information immediately, the image information from the other party is received by the facsimile interface 47 via the communication line and expanded, and then sent to the engine control unit 40 via the controller 39. The printer unit 42 prints on paper. When the received image information is stored in the storage device 46, the image information from the other party is received by the facsimile interface 47 via the communication line and is stored in the storage device 46 while being compressed. The received image information stored in the storage device 46 can be displayed by the host 38 via the controller 39 on the display 21b for confirmation, and can be printed by the printer unit 42 as described above as necessary. it can.

A double-sided machine 43, which is an optional double-sided image forming mechanism, is detachably attached to the upper portion as shown in FIG. 3, and when the double-sided machine 43 is used, the document discharge port 16 is used as a sheet passage port. Therefore, the scanner function cannot be used. Therefore, the use of the double-sided print function is limited to the use of the print function.

At the time of double-sided printing, first, an image is printed on the front surface of the paper as in the above-described image formation, and the paper is ejected from the paper ejection port 12. Here, the branch guide 48 including a branch claw is controlled by the engine control unit 40, and is normally switched to the position indicated by the solid line in FIG. 3 so that the print from the discharge port 12 is discharged to the paper discharge unit 13. At the time of double-sided printing with the double-sided machine 43 attached, the branching claw 48 is switched to the position indicated by the dotted line in FIG. 3, and the paper from the paper discharge unit 13 is fed into the double-sided machine 43 by the branching claw 48.

The paper discharge sensor 49 detects the paper near the paper discharge port 12 and outputs a detection signal to the engine control unit 40. The engine control unit 40 monitors the detection signal from the paper discharge sensor 49 and confirms that the paper has passed near the paper discharge port 12 and then waits a certain time (the paper is discharged from the paper discharge roller 2).
9) After being fed to the double-sided machine 43), the main body of the present embodiment (parts other than the optional manual sheet feeder 15 and the double-sided machine 43) and the double-sided machine 43 are stopped and the disengagement clutch is turned off to drive. Section and the image forming section are separated.

After that, the engine control section 40 rotates the drive section in the reverse direction to rotate the registration roller 20 in the reverse direction,
After the branching claw 37 is switched to the document discharge port 16 side (document transport path side), the driving of the double-sided machine 43 is started. The double-sided machine 43 conveys the paper fed from the paper discharge roller 29 along the double-sided use passage 50 and feeds it from the document discharge port 16 into the main body. In the main body, the sheet fed from the document discharge port 16 by the double-sided machine 43 is conveyed in the opposite direction along the document conveying path and is conveyed in the opposite direction along the common part of the document conveying path and the sheet conveying path, and the registration is performed. The roller 20 conveys the sheet in the reverse direction.

At this time, the engine control section 40 detects the jam of the sheet from the detection signal from the registration sensor 21. Further, the engine control unit 40 uses the registration sensor 21.
It is detected from the detection signal from the register sensor 21 that it is turned on by the paper, and the time from then is monitored. After this time reaches a specified time corresponding to the size of the paper in the conveyance direction, the main body is driven and the duplexer 43 The driving is stopped to stop the registration roller 20. At this time, the leading edge of the sheet is gripped by the registration roller 20, and the sheet is stopped on the sheet conveyance path from the sheet discharge port 12 via the duplexer 43, so that the front and back sides are reversed.

Further, the engine control unit 40 includes the branch claw 3
7 is switched to the sheet conveyance path side and the disengagement clutch is turned on to connect the drive unit and the image forming unit, the drive unit is rotated in the forward direction to drive the main body in the forward direction, and the back surface printing from the controller 39 is performed. Waiting for the command, the printer unit 42 is controlled to create a print as in the above-described image formation. In this case, since the front and back of the paper are reversed, the image is printed on the back. This sheet is discharged from the sheet discharge port 12 to the sheet discharge unit 13.

As described above, during double-sided printing, the main body is driven in the reverse direction by the drive unit, so the engine control unit 40 separates the image forming unit and the drive unit during the period in which the main body is driven in the reverse direction. If the toner replenishing unit 25b is replenishing toner when the image forming unit and the driving unit are separated, the toner replenishing unit 25b functions in conjunction with the image forming unit, so that the image forming unit and the driving unit are separated. After that, it does not function and toner cannot be replenished, and it is necessary to control the separation of the image forming unit and the drive unit from the toner replenishment unit 25b.

Therefore, in this embodiment, the engine control unit 4
0 determines whether or not the toner replenishing unit 25b is replenishing toner when the image forming unit and the driving unit are separated as shown in FIG. 4, and if the toner replenishing unit 25b is not replenishing toner, immediately disconnects. The clutch is turned off to disconnect the image forming unit and the drive unit. If the toner replenishment unit 25b is replenishing toner, the engine control unit 40 turns off the toner replenishment clutch to stop the toner replenishment unit 25b,
After the toner supply of the toner supply unit 25b is completed, the disengagement clutch is turned off to disconnect the image forming unit and the drive unit.

In the first embodiment, the image forming unit and the driving unit are immediately separated from each other if the toner is not being supplied when the image forming unit and the driving unit are separated from each other. Since the forming unit and the driving unit are separated, the toner can be replenished accurately even if the image forming unit and the driving unit are separated. This method can be performed by the simplest and simplest control sequence without using a dedicated control mechanism, and can be added to conventional functions without any major change or addition in control.

In the second embodiment of the present invention, in the above first embodiment, when the image forming unit and the driving unit are separated from each other, it is not possible to wait until the toner supply is completed and the image forming unit and the driving unit are separated. That is, when the separation timing of the image forming unit and the driving unit cannot be fixed or extended, the separation of the image forming unit and the driving unit is preferentially performed. The second embodiment is an embodiment of the invention according to claim 3, and in the first embodiment, the engine control unit 40 is used.
Performs the processing shown in FIGS. 5 and 6 instead of the processing shown in FIG.

That is, the engine control unit 40 determines whether or not the toner replenishing unit 25b is in the process of replenishing toner when the image forming unit and the driving unit are separated as shown in FIG. If replenishment is not in progress, the disengagement clutch is immediately turned off to disconnect the image forming unit and the drive unit. In addition, the engine control unit 40 uses the toner supply unit 2
If 5b is replenishing toner, the remaining toner replenishment time of the toner replenishing section 25b is stored in the storage means and the toner replenishing section 2b is stored.
The toner supply of 5b is stopped, the disengagement clutch is turned off, and the image forming unit and the drive unit are separated.

Thereafter, as shown in FIG. 6, the engine control unit 40 determines whether or not there is a remaining toner replenishment time from the contents of the storage means at the time of starting the back side printing in which the image forming unit and the driving unit are connected. If there is a remaining toner replenishment time, the toner replenishment clutch is turned on for the remaining toner replenishment time to cause the toner replenishment section 25b to replenish the remaining toner. In the second embodiment, even when the separation timing of the image forming unit and the driving unit is fixed or cannot be extended, the separation of the image forming unit and the driving unit is prioritized, and
The toner can be replenished accurately.

In the second embodiment, when the timing of image writing by the laser optical system 24 is reached while the remaining toner is being replenished, the toner replenishment induces noise and affects the image writing. there is a possibility. Therefore, a third embodiment of the present invention is the same as the second embodiment,
The engine control unit 40 performs the processing shown in FIG. 7 instead of the processing shown in FIG.

In other words, the engine control unit 40 connects the image forming unit and the driving unit, and the driving unit rotates in the forward direction to drive the main body in the forward direction. It is determined whether there is a toner replenishment time. If there is no remaining toner replenishment time, the registration roller 20 is rotated to start back surface printing, and if there is a remaining toner replenishment time, the remaining toner is first The toner replenishing clutch is turned on for the replenishment time to cause the toner replenishing section 25b to replenish the remaining toner. Then, after confirming that the remaining toner supply is completed, the engine control unit 40 rotates the registration roller 20 to start back surface printing.

The third embodiment is an embodiment of the invention described in claim 4, and since the back surface printing is started after the remaining toner is replenished, the laser optical is performed while the remaining toner is replenished. Even if the toner replenishment induces noise at the timing of image writing by the system 24, it does not affect the image writing and the toner can be replenished accurately.

In the third embodiment described above, the time required for double-sided printing for one sheet (the time from the paper feeding for performing the front surface printing to the paper discharging to the paper discharging unit 13 after the back surface printing) is not constant. There's a problem. Therefore, the fourth embodiment of the present invention is different from the second embodiment in the engine control unit 40.
The processing shown in FIG. 8 is performed instead of the processing shown in FIG.

That is, the engine control unit 40 determines whether the back side printing has been performed up to the trailing edge of the sheet, and when the back side printing has been performed up to the trailing edge of the sheet, the remaining toner is replenished from the contents of the storage means. When it is judged whether or not there is time, when there is no remaining toner replenishment time, the toner replenishment clutch is turned on to start the toner replenishment by the back side print in the toner replenishment section 25b.

Further, if there is a remaining toner supply time, the engine control unit 40 operates the toner supply clutch for the toner supply unit 25b for a time corresponding to the total time of the remaining toner supply time and the time of the toner supply by the back side printing. When turned on, the toner replenishing section 25b is made to perform the replenishment of the remaining toner and the toner replenishment by backside printing. The fourth embodiment is an embodiment of the invention described in claim 5, and assuming that the time required for the front surface printing and the back surface printing of the paper is constant, one sheet of double-sided printing is always supplied from paper feeding to paper ejection. It will be done in a fixed time.

In another embodiment of the present invention, a nonvolatile memory is used as the storage means in the first to fourth embodiments, and an embodiment of the invention according to claim 6 is provided. is there. In this embodiment, even if an unexpected situation such as the power being turned off before the toner supply by the stored contents of the storage means is not completed, the remaining toner is supplied when the power is turned on again. The toner can be replenished more accurately.

[0056]

As described above, according to the first aspect of the present invention, the sheet transport path for transporting the sheet and discharging it from the sheet discharge port, and the toner replenishing section for replenishing toner are provided by the sheet transport path. An image forming unit that forms an image on a sheet to be conveyed, an original conveyance path that shares a part with the sheet conveyance path and conveys an original and discharges it from an original discharge port, and an original conveyance path that conveys the original. A document reading unit that reads an image from a document, a double-sided image forming mechanism that sends a sheet having an image formed on one side by the image forming unit from the document discharge port to the document conveyance path, and a drive for the toner replenishing unit. Used to drive the image forming unit in the forward direction to form an image on one side of a sheet, and further drive the double-sided image forming mechanism to form a sheet after single-sided image formation on the double-sided image forming mechanism and the double-sided image forming mechanism. A drive unit that drives the image forming unit in the forward direction to form an image on the other surface of the paper after returning to the paper conveyance path via a part of the paper conveyance path, and the paper conveyance path to the paper discharge port. Side and the double-sided image forming mechanism side, and switching means for switching a common part of the paper transport path and the document transport path between the paper transport path side and the document transport path side, and the double-sided image formation. In the image forming apparatus, which has a disconnecting unit that disconnects the driving unit and the image forming unit when the operating mechanism is operated, and the toner replenishing unit interlocks with the image forming unit, the toner replenishing unit and the disconnecting unit are controlled. Since the control means is provided, the toner can be replenished accurately even if the image forming unit and the driving unit are separated.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the toner replenishing means causes the control means to separate the drive section from the image forming section by the separating means. When replenishing the toner, replenishing means waits until the toner replenishment of the toner replenishing means is completed, and causes the separating means to separate the drive section and the image forming section. Therefore, even if the image forming section and the drive section are separated from each other. The toner can be replenished accurately, and a simple control sequence can be performed without using a dedicated control mechanism.

According to a third aspect of the present invention, in the image forming apparatus according to the first aspect, the control unit controls the toner replenishing unit when the separating unit separates the drive unit and the image forming unit from each other. When toner is being replenished, the remaining toner replenishment time of the toner replenishing means is stored in the storage means, the toner replenishment of the toner replenishing means is stopped, and the drive unit and the above-mentioned means are used to form an image on the other surface of the paper. When the image forming unit is connected, the toner replenishing unit is made to replenish the toner for the remaining toner replenishment time stored in the storage unit, so that the separation timing between the image forming unit and the drive unit cannot be fixed or extended. Even in this case, it is possible to give priority to the separation between the image forming unit and the driving unit and to accurately supply the toner.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the toner replenishing section is stored in the toner replenishing section by connecting the driving section and the image forming section during image formation on the other surface of the sheet. Since the other surface image formation of the paper is started after the toner supply for the remaining toner supply time stored in the means is started, the image formation timing is reached during the remaining toner supply and the toner supply is completed. Even if the noise is induced, it does not affect the image formation, and the toner can be replenished accurately.

According to a fifth aspect of the present invention, in the image forming apparatus according to the third aspect, the control unit causes the toner replenishing unit to replenish the toner for the remaining toner replenishment time stored in the storage unit. After the completion of the image formation on the other surface, the toner is supplied together with the image formation on the other surface of the paper, so that it is possible to eliminate the non-uniformity of the time required for one double-sided printing.

According to the sixth aspect of the invention, in the image forming apparatus according to the third aspect, since the storage means is a non-volatile storage means, the toner replenishment based on the stored contents of the storage means is not completed. Even if an unexpected situation such as power-off occurs, toner can be replenished accurately.

[Brief description of drawings]

FIG. 1 is a block diagram showing an electric component part of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mounted state of the manual paper feeding device of the first embodiment.

FIG. 3 is a cross-sectional view showing a mounted state of the double-sided machine of the first embodiment.

FIG. 4 is a flowchart showing a part of a processing flow of an engine control unit in the first embodiment.

FIG. 5 is a flowchart showing a part of a processing flow of an engine control unit in the second embodiment of the present invention.

FIG. 6 is a flowchart showing a part of a processing flow of an engine control unit in the third embodiment of the present invention.

FIG. 7 is a flowchart showing another part of the processing flow of the engine control unit in the third embodiment.

FIG. 8 is a flowchart showing a part of a processing flow of an engine control unit in the fourth embodiment of the present invention.

[Explanation of symbols]

 38 host 39 controller 40 engine control unit 41 scanner unit 42 printer unit 43 double-sided machine

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Claims (6)

[Claims] 1. A paper transporting path for transporting a paper and discharging it from a paper discharge port, and an image forming section for forming an image on the paper transported through the paper transporting path, which has a toner replenishing section for replenishing toner. An original document conveyance path that is partly common with the paper sheet conveyance path and conveys an original document and discharges it from an original document ejection port, an original document reading unit that reads an image from the original document conveyed by the original document conveyance path, and the image forming apparatus. Used for driving a double-sided image forming mechanism that feeds a sheet on which an image is formed on one side from the document discharge port to the document conveying path, and for driving the toner replenishing unit, and drives the image forming unit in the forward direction. An image is formed on one side of a sheet, and the double-sided image forming mechanism is driven to feed the sheet on which the single-sided image has been formed through the double-sided image forming mechanism and a part of the original document conveying path. And a drive unit that drives the image forming unit in the forward direction to form an image on the other surface of the paper after returning, and switches the paper transport path to the paper discharge port side and the double-sided image forming mechanism side, and Switching means for switching a common part of the paper transport path and the document transport path between the paper transport path side and the document transport path side; and the drive section and the image forming section during operation of the double-sided image forming mechanism. An image forming apparatus in which the toner replenishing unit is interlocked with the image forming unit,
An image forming apparatus comprising: a control unit that controls the toner supply unit and the separation unit. 2. An image forming apparatus according to claim 1, wherein said control means is said toner replenishing means when said toner replenishing means is replenishing toner when said separating means separates said drive section and said image forming section from each other. An image forming apparatus, characterized in that the separating unit separates the drive unit and the image forming unit after the toner supply of the toner supply unit is completed. 3. The image forming apparatus according to claim 1, wherein said control means is such that said toner replenishing means is replenishing toner when said separating means separates said drive section and said image forming section from each other. The remaining toner replenishment time of the toner replenishing means is stored in the storage means, the toner replenishment of the toner replenishing means is stopped, and the drive unit and the image forming unit are connected to form an image on the other surface of the paper. An image forming apparatus, characterized in that the toner replenishing section is made to replenish toner for the remaining toner replenishment time stored in the storage means. 4. The image forming apparatus according to claim 3, wherein the drive unit and the image forming unit are connected to each other when the other surface image of the sheet is formed, and the toner replenishing unit is stored in the storage unit. An image forming apparatus, wherein image formation on the other surface of a sheet is started after toner is supplied for a supply time. 5. The image forming apparatus according to claim 3, wherein the control unit supplies toner for the remaining toner supply time stored in the storage unit by the toner supply unit after completion of image formation on the other surface of the paper. An image forming apparatus characterized in that it is performed together with toner supply by image formation on the other surface. 6. The image forming apparatus according to claim 3, wherein the storage means comprises a non-volatile storage means.