JP2013249177A - Image forming apparatus and sheet feeding apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an apparatus and reduce manufacturing costs by reducing the number of signal lines.SOLUTION: A printing apparatus 100 generates a two-bit sheet feeding reference signal changing to a high voltage pulse or a low voltage pulse on the basis of a registration sensor 501 detecting the arrival of a printing sheet 10 to registration rollers 240a, 240b, and transmits it to a sheet feeding device 400 through a single signal line 20. When receiving the sheet feeding reference signal, the sheet feeding device 400 causes operation of intermediate conveying rollers 431, 432, 433 to be synchronized with operation of pre-registration rollers 230a, 230b on the basis of an operation pattern about the intermediate conveying rollers 431, 432, 433.

Description

  The present invention relates to an image forming apparatus that forms an image on a recording medium that is transported on a transport path, and a paper feeding device that supplies the recording medium to the image forming apparatus.

  In an image forming apparatus such as an ink jet system, a registration roller is generally disposed upstream of an image forming unit on a conveyance path, and is supplied from a scraper roller and a pickup roller that convey recording media loaded on a sheet feeding tray one by one. A mechanism that temporarily holds the recording medium to be recorded and adjusts the sending timing of the recording medium with respect to the conveyance path is employed. In addition, in order to print a large amount of recording media of the same size, an external device such as a large-capacity paper feeding unit loaded with a large amount of recording media is detachably attached to the image forming apparatus or attached to the device. It is built in.

  By the way, for this large-capacity paper feed unit, it is necessary to secure a maintenance space such as a space for clearing a paper jam in the paper feed path, and while securing a certain distance from the pickup roller to the registration roller, In order to stably transport recording media of various sizes, a plurality of intermediate transport rollers are arranged between the pickup roller and the registration roller.

  Usually, the intermediate transport roller is driven by an electromagnetic clutch that is driven by the action of electromagnetic force using an electromagnet or a one-way clutch that transmits rotational force only in one direction. When such an electromagnetic clutch or one-way clutch is used, when the registration roller provided on the downstream side sandwiches the recording medium, the drive of the intermediate conveyance roller is turned off. Thereafter, the intermediate conveyance roller is driven by the registration roller. The recording medium is prevented from running backward upstream in the transport direction by so-called “spinning” that idles in accordance with the transport of the paper.

  Here, when the intermediate transport roller is rotated, the recording medium is gripped by friction between the intermediate transport roller and the recording medium, and reverse tension (back tension) is generated on the recording medium. It was. This back tension may cause a conveyance timing delay, an image position shift, and a paper jam, and if a conveyance timing delay occurs, the speed of image forming processing is hindered. was there.

  With respect to this, for example, it has been devised that the speed correction for the delay or advance of the recording medium is performed by a pre-registration roller upstream of the registration roller. However, since the pre-registration roller also needs to perform “abutting correction control” for correcting the skew of the sheet, if the pre-registration roller is used only for the delay advance speed correction control and the abutting correction control, However, the gap between the conveyance speed and the printing speed cannot be solved, and the control of the pre-registration roller becomes a bottleneck, and there is a problem that a certain restriction occurs in the speeding up of the entire image forming apparatus.

  In order to solve such a problem, there is, for example, Patent Document 1. Patent Document 1 includes driving means such as a pickup roller and an intermediate conveyance roller installed in an external device, and control means (controller) for controlling each driving means. In order to synchronize each driving unit with the operation of the image forming apparatus, signals such as a clock signal (CLK), a command signal (CMD), and a timing signal (TMG) are provided between the image forming apparatus and the external apparatus. A line is individually connected to each drive means. Then, by individually controlling each drive unit in accordance with these signals, the conveyance timing of the external apparatus is synchronized with the conveyance timing on the image forming apparatus side.

JP 2009-300094 A

  However, as disclosed in Patent Document 1, when signal lines such as a clock signal (CLK), a command signal (CMD), and a timing signal (TMG) are connected between the image forming apparatus and an external apparatus. In this case, the number of signal lines increases, which increases the size of the device and increases the manufacturing cost.

  The present invention has been made in view of the above points. In order to link an image forming apparatus and a paper feeding apparatus, the image forming apparatus and the paper feeding apparatus are linked with each other when an image forming system is constructed. It is an object of the present invention to provide an image forming apparatus and a sheet feeding apparatus that can reduce the number of signal transmission signal lines and the number of connection ports thereof.

In order to achieve the above object, an image forming apparatus according to a first aspect of the present invention provides:
Image forming apparatus for receiving a recording medium supplied from a sheet feeding device that conveys a recording medium picked up by a pickup roller from a sheet feeding tray by an intermediate conveying roller group and forming an image on the recording medium while conveying the recording medium on a conveying path Because
A registration roller that adjusts the delivery timing of the received recording medium with respect to the transport path;
A pre-registration roller for feeding the recording medium received from the paper feed path to the registration roller;
A registration sensor that detects the recording medium on the upstream side of the registration roller in the conveyance direction of the recording medium;
Image forming control means for controlling the operation of the pre-registration roller based on the detection timing of the recording medium by the registration sensor;
Supply that alternately repeats signal level changes at a first timing at which the pickup roller picks up the recording medium and a second timing at which the intermediate conveyance roller group starts to synchronize operation with the pre-registration rollers. A signal output means for outputting a paper reference signal to the paper feeding device;
It is characterized by providing.

In order to achieve the above object, a sheet feeding device according to the present invention described in claim 3
A sheet feeding device having a sheet feeding path for supplying a recording medium conveyed from a pre-registration roller of an image forming apparatus to a conveyance path via a registration roller, to the image forming apparatus,
A pickup roller for picking up the recording medium to the paper feed path;
An intermediate conveyance roller group for conveying the recording medium picked up by the pickup roller on the paper feed path;
A signal level at a first timing at which the intermediate conveyance roller group finishes rotating in synchronization with the pre-registration roller and at a second timing at which the intermediate conveyance roller group starts rotation in synchronization with the pre-registration roller. A signal input means for inputting a paper feed reference signal supplied from the image forming apparatus, wherein the change is repeated alternately;
Storage means for storing a rotation pattern of the pre-registration roller from the second timing to the first timing;
Paper feed control means for controlling operations of the pickup roller and the intermediate transport roller group based on the paper feed reference signal and the rotation pattern of the storage means;
It is characterized by providing.

  According to the image forming apparatus of the present invention described in claim 1 and the sheet feeding apparatus of the present invention described in claim 3, the signal level changes alternately at the first timing and the second timing. The repeated signal constitutes a paper feed reference signal for synchronizing the rotation timing of the pickup roller and the intermediate transport roller group of the paper feeding device with the rotation timing of the pre-registration roller of the image forming apparatus. For this reason, for example, the paper feed reference signal can be constituted by a pulsed 2-bit signal that repeats a high level and a low level. Therefore, the link between the image forming apparatus and the sheet feeding apparatus can be realized by transmitting the sheet feeding reference signal using one signal line and one connection port.

The image forming apparatus of the present invention described in claim 2 is the image forming apparatus of the present invention described in claim 1,
The image formation control means
The pre-registration roller is decelerated to a predetermined speed by a predetermined deceleration pattern for a predetermined period from the second timing until the stopped registration roller resumes rotation, and at least until the first timing. Rotating in synchronization with the registration roller;
It is characterized by that.

The image forming apparatus of the present invention described in claim 4 is the image forming apparatus of the present invention described in claim 3.
The paper feed control means
Rotating the pickup roller to pick up the recording medium at the first timing;
Based on the rotation pattern of the storage means, the intermediate transport roller group is synchronized with the pre-registration roller for a predetermined period from the second timing until the stopped registration roller resumes rotation. After decelerating to a predetermined speed by a deceleration pattern, rotate at least until the first timing in synchronization with the registration roller,
It is characterized by that.

  According to the image forming apparatus of the present invention described in claim 2 and the paper feeding apparatus of the present invention described in claim 4, the image forming apparatus of the present invention described in claim 1 and the image forming apparatus described in claim 3 are described. In the paper feeding device of the present invention, it is as follows.

  That is, in the image forming apparatus, when the pre-registration roller decelerates over a predetermined period from the second timing until the stopped registration roller resumes rotation, the recording medium is moved between the registration roller and the pre-registration roller. The registration roller is bent at the top. Therefore, in the image forming apparatus, when the registration roller and the pre-registration roller start to rotate synchronously after a predetermined period has elapsed, the skew is corrected by the registration roller even if the recording medium has been skewed until then. Thus, the recording medium is sent out on the transport path.

  On the other hand, in the sheet feeding device, the rotation of the intermediate transport roller group is synchronized with the rotation of the pre-registration roller of the image forming apparatus by the sheet feeding reference signal from the second timing to the first timing. Therefore, the rotation of the intermediate conveyance roller group of the paper feeding device can be synchronized with the series of rotation patterns of the pre-registration rollers for correcting the skew feeding of the recording medium in the image forming apparatus by transmitting the paper feeding reference signal.

In addition,
A sheet feeding device that conveys a recording medium picked up by a pickup roller from a sheet feeding tray by an intermediate conveyance roller group, and a recording medium supplied from the sheet feeding device are received on a conveying path from a pre-registration roller through a registration roller. An image forming system having an image forming apparatus that forms an image on the recording medium while being conveyed,
The image forming apparatus according to claim 1 or 2, and the paper feeding device according to claim 3 or 4.
An image forming system characterized by this can also be configured.

  According to the image forming system configured as described above, the effect obtained by the image forming apparatus according to the present invention described in claim 1 or 2, and the paper feeding apparatus according to the present invention described in claim 3 or 4. The effects obtained in the above can be obtained together.

  According to the present invention, when constructing an image forming system in which an image forming apparatus and a paper feeding apparatus are connected and interlocked, a signal transmission signal line for interlocking the image forming apparatus and the paper feeding apparatus and the signal line The number of connection ports can be reduced.

FIG. 2 is a schematic diagram illustrating an outline of a printing paper conveyance path of a printer system according to an embodiment of the present invention. FIG. 2 is an enlarged side view showing a part of a paper feed system conveyance path in FIG. 1. FIG. 2 is a block diagram illustrating modules relating to paper feed control of the paper feeder and printing apparatus of FIG. 1. FIG. 4 is a time chart illustrating sheet feeding control by an arithmetic processing unit of the printing apparatus of FIG. 3 and signal output for synchronization with the sheet feeding apparatus. FIG. 4 is a flowchart illustrating a sheet feeding operation performed in synchronization between the printing apparatus and the sheet feeding apparatus of FIG. 3.

(Overall configuration of printer system)
Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram showing an outline of a printing paper transport path of a printer system according to an embodiment of the present invention. In the figure, the number of rollers constituting the drive unit is omitted as appropriate.

  A printing apparatus 100 (image forming apparatus) of the printer system 1 (image forming system) of the present embodiment illustrated in FIG. 1 is an inkjet line color printer. The printing apparatus 100 includes a plurality of ink heads each having a large number of nozzles, discharges black or color ink from each of the ink heads, performs printing in units of lines, and prints a plurality of images on a recording sheet on a conveyance belt. Form to overlap.

  The printer system 1 includes a printing apparatus 100 that forms an image on a printing paper 10 that is a recording medium that is conveyed on a conveyance path, and a paper feeding path that feeds the printing paper 10 (recording medium) to the printing apparatus 100. The sheet feeding device 400. The transport path of the printer 100 and the paper feed path of the paper feeder 400 constitute the print paper transport path of the printer system 1.

(1) Image Forming Apparatus As shown in FIG. 1, a printing apparatus 100 is an image forming apparatus that forms an image on a printing paper 10 that is conveyed on an annular conveyance path. The paper path is generally composed of a paper transport path FR, a normal path CR from the paper feed system transport path FR through the head unit 110 to the paper discharge path DR, and a reverse path SR branched and connected to the normal path CR.

  A plurality of paper feed trays (130a, 130b, 130c, 130d) provided inside the housing are provided as a paper feed mechanism for supplying the printing paper 10 in the paper feed system conveyance path FR.

  The print paper 10 fed from the paper feed trays (130a, 130b, 130c, 130d) is transported along a paper feed system transport path FR in the housing by a driving mechanism such as a roller, and the top of the print paper 10 is printed. It is guided to the resist portion R which is the reference position. Then, the printing paper 10 is supplied to the registration rollers of the registration unit R by driving the rollers upstream of the registration rollers.

  On the other hand, a head unit 110 having a plurality of print heads is provided on the downstream side of the registration portion R in the transport direction. The printing paper 10 is image-formed line by line with ink ejected from each printing head while being conveyed at a speed determined by printing conditions by a conveying belt 160 provided on the opposite surface of the head unit 110. The printed printing paper 10 is further conveyed on the normal route CR by a driving mechanism such as a roller. A discharge port 140 is branched and connected to the normal route CR as a discharge mechanism for discharging the printed printing paper 10.

  In the case of single-sided printing in which printing is performed only on one side of the printing paper 10, the printing paper 10 is directly discharged to the paper discharge outlet 140 through the paper discharge path DR and received by the paper discharge outlet 140. The paper is stacked on a paper discharge table 150 provided as a table with the printing surface facing down. The paper discharge table 150 has a tray shape protruding from the housing, and has a certain thickness. The paper discharge table 150 is inclined, and the printing paper 10 discharged from the paper discharge port 140 is naturally arranged and overlapped by a wall formed at a lower position of the inclination.

  On the other hand, in the case of double-sided printing in which printing is performed on both sides of the printing paper 10, the front side (the first printed side is “front side” and the next printed side is “back side”). Without being guided to the side, it is further transported in the housing and sent out to the reversing path SR. A switching mechanism 170 for switching the transport path for back side printing is provided at a branch point between the paper discharge path DR and the reversal path SR, and the printing paper 10 that has not been sent to the discharge path by the switching mechanism 170 is provided. , Is pulled into the reversal path SR.

  In the reversing path SR, the sheet is delivered from the normal path CR, and so-called switchback is performed in which the sheet is reversed by reciprocating the sheet. Then, it is returned to the normal route CR via the switching mechanism 172 by a driving mechanism such as a roller, and is fed again via the registration portion R, and the back side is printed by the same procedure as the front side. Thereafter, the printing paper 10 on which the back side is printed and the images are formed on both sides is guided to the paper discharge port 140 through the paper discharge route DR and discharged, and is discharged as a receiving tray for the paper discharge port 140. It is loaded on the paper table 150. In the present embodiment, switchback at the time of duplex printing is performed using a space provided in the paper discharge tray 150. The space provided in the paper discharge tray 150 is configured to be covered so that the printing paper 10 cannot be taken out from the outside during switchback.

  In the printing apparatus 100, the printing paper 10 that has already been printed on one side is also re-fed to the registration portion R that is the reference position of the leading portion of the fed printing paper 10 during duplex printing. For this reason, at the portion immediately before the registration unit R, a junction 214 where the feeding path of the newly fed printing paper 10 and the refeeding path through which the backside printing paper is circulated and joined is joined. Is formed. Then, the registration unit R sends out the paper at the downstream side of the junction 214 between the paper feeding system conveyance path FR and the normal path CR.

  In the present embodiment, after a certain printing paper 10 is fed, the next printing paper 10 is not fed after waiting for the printing on the printing paper 10 to be discharged, but by scheduling. Before the preceding printing paper 10 is discharged, the succeeding printing paper 10 can be fed and continuously printed at a predetermined interval. Therefore, in normal scheduling at the time of duplex printing, a space is secured in advance so as to secure a position where the sheet returned from the reversing path SR is inserted when feeding the front sheet. Thereby, in this apparatus, printing on the front surface and printing on the back surface can be performed in parallel, and productivity twice as high as that during single-sided printing can be ensured.

  The conveying belt 160 is wound around a driving roller 161 and a driven roller 162 disposed at the front end and the rear end of the surface facing the head unit 110 in the normal path CR. Rotate. Further, on the upper surface of the transport belt 160, ink heads of four colors are arranged side by side along the belt moving direction, and a head unit 110 that forms a color image so as to overlap a plurality of images is opposed to the head unit 110. Yes.

  In the printing apparatus 100 described above, a paper feeding device 400 is disposed on the upstream side in the paper conveyance direction. In the paper feeding device 400, the printing paper 10 stored in the paper feeding device 400 is guided to the registration unit R on the printing device 100 side through the external paper feeding path FR1.

  Further, as illustrated in FIG. 1, the printing apparatus 100 includes an arithmetic processing unit 330. The arithmetic processing unit 330 is configured by a processor such as a CPU or DSP (Digital Signal Processor), hardware such as a memory and other electronic circuits, software such as a program having the function, or a combination thereof. This is an arithmetic module. The arithmetic processing unit 330 virtually constructs various functional modules by appropriately reading and executing a program, and by the constructed functional modules, various processing for image data, operation control of each unit, and various user operations are performed. Process. In addition, an operation panel 340 is connected to the arithmetic processing unit 330, and an instruction and a setting operation by a user can be received through the operation panel 340.

(2) Paper feeder 400
Next, a paper feeding path of the paper feeding device 400 will be described. The paper feeding device 400 is a paper feeding unit that is detachably mounted in order to assist paper feeding of the paper feeding tray 130 provided in the printing device 100 or to support a large capacity image forming process. is there.

  In the present embodiment, the paper feeding device 400 has an external paper feeding path FR1 connected to the paper feeding system conveyance path FR. In the external paper feed path FR1, the printing paper 10 fed from the paper feed tray 401 that stores a large number of sheets of a predetermined size is stored in the printing apparatus 100 by a driving mechanism such as a roller on the external paper feed path FR1. The sheet is conveyed along the sheet feeding system conveyance path FR. As a result, the printing paper 10 is guided to the registration portion R, which is the reference position of the leading portion of the printing paper 10, and the printing paper 10 is supplied by driving each upstream roller.

  Further, as shown in FIG. 1, the paper feeding device 400 is also provided with an arithmetic processing unit 440. The arithmetic processing unit 440 is also configured by a processor such as a CPU or DSP (Digital Signal Processor), memory, hardware such as other electronic circuits, software such as a program having the function, or a combination thereof. This is an arithmetic module. The arithmetic processing unit 440 virtually constructs various functional modules by appropriately reading and executing a program, and performs operation control of each unit that transports the printing paper 10 by the constructed functional modules.

  Here, the printing apparatus 100 and the paper feeding apparatus 400 are electrically connected by a single signal line 20. The arithmetic processing unit 330 provided in the printing apparatus 100 controls the operation of the paper feeding device 400 by transmitting a command signal to the arithmetic processing unit 440 of the paper feeding device 400 through the single signal line 20.

(Paper feed mechanism)
In the present embodiment, the above-described paper feeding system conveyance path FR and external paper feeding path FR1 are linked to each other to supply a part of a printing paper conveyance mechanism that supplies the printing paper 10 from the paper feeding apparatus 400 to the printing apparatus 100. The paper mechanism is configured. FIG. 2 is an enlarged side view showing a part of the paper feed system conveyance path FR and the external paper feed path FR1. As shown in the figure, the paper feed mechanism of the present embodiment is configured by the above-described paper feed system conveyance path FR and external paper feed path FR1, and is a mechanism for sending the printing paper 10 to the registration unit R. In the present embodiment, the printing paper 10 is supplied to the registration unit R through the external paper feeding path FR1 for newly feeding paper from the paper feeding device 400 disposed outside the side surface of the casing of the printing apparatus 100. The

  In the registration unit R arranged in the printing apparatus 100, registration rollers 240a and 240b constituting the registration motor driving unit 240 are arranged upstream of the head unit 110 in the normal path CR. The registration rollers 240a and 240b temporarily hold the printing paper 10 entering the normal path CR from the paper feeding system conveyance path FR side, and adjust the sending timing of the printing paper 10 to the head unit 110. . Further, in the registration unit R, pre-registration rollers 230a and 230b constituting the pre-registration motor drive unit 230 are arranged adjacent to the upstream side of the conveyance path with respect to the registration rollers 240a and 240b. The pre-registration rollers 230a and 230b send the printing paper 10 from the external paper feed path FR1 to the registration rollers.

  The registration motor drive unit 240 of the registration rollers 240a and 240b holds the printing paper 10 related to paper feeding by a pair of rollers (registration rollers 240a and 240b), and adjusts the sending timing of the printing paper 10 to the image forming unit. It is. The registration motor driving unit 240 is controlled by the conveyance driving control unit 350 on the image forming side to start and stop the operation and the operation speed, and controls the acceleration at the start-up and the deceleration acceleration at the time of deceleration.

  The pre-registration motor driving unit 230 of the pre-registration rollers 230a and 230b holds the printing paper 10 related to paper feeding by a pair of rollers (pre-registration rollers 230a and 230b) under the control of the conveyance drive control unit 350 on the image forming side. The printing paper 10 is sent to the registration rollers 240a and 240b while decelerating in accordance with the stop of the registration rollers, and the skew of the printing paper 10 with respect to the registration rollers 240a and 240b is corrected, and the image forming unit This is a driving means for performing so-called “abutting correction control” for adjusting the sending timing of the printing paper 10 to the printer. In the “butting correction control”, the skew of the paper is corrected by correcting the orientation of the printing paper 10 conveyed obliquely to be straight and sending it to the subsequent stage (conveying belt 160).

  Further, a resist sensor 501 is provided in the resist portion R. The registration sensor 501 is a sensor that is installed close to the upstream side of the registration rollers 240a and 240b and detects the arrival of the printing paper 10 to the registration rollers 240a and 240b. In the present embodiment, a reflection sensor, a transmission sensor, and other various sensors can be used as the registration sensor 501.

  On the other hand, a paper feed tray 401 on which the printing paper 10 is stacked is provided upstream in the transport direction of the external paper feed path FR <b> 1 arranged in the paper feed device 400, and a pickup motor driving unit 420 is disposed above the paper feed tray 401. The upstream side pickup roller 420a and the downstream side scraper roller 420b are provided. Then, the uppermost printing paper 10 is picked up one by one from among the printing papers 10 stacked by rotating these rollers, and is sent to the external paper feeding path FR1.

  In the external paper feed path FR1, a plurality of intermediate transport rollers 431 (431a, 431b), 432 (432a, 432b), 433 constituting the intermediate transport motor drive unit 430 are arranged downstream of the pickup roller 420a in the transport direction. (433a, 433b) are provided along the path. Then, the printing paper 10 is sent to the registration unit R by the intermediate conveyance rollers 431, 432, and 433. These intermediate conveyance rollers 431, 432, and 433 constitute an intermediate conveyance roller group in claims.

  The pickup motor drive unit 420 of the pickup roller 420a and the scraper roller 420b directly rotates the pickup roller 420a and indirectly controls the scraper roller 420b via a belt pulley mechanism under the control of the conveyance drive control unit 450 on the paper feed side. This is a driving means that picks up the printing paper 10 one by one and sends it to the external paper feeding path FR1.

  The intermediate conveyance motor drive unit 430 of the intermediate conveyance rollers 431, 432, and 433 is controlled by a conveyance drive control unit 450 on the paper feeding side, and a plurality of arranged rollers (intermediate conveyance rollers 431 (431a, 431b), The driving unit 432 (432a, 432b) and 433 (433a, 433b) holds the printing paper 10 related to paper feeding and adjusts the sending timing of the printing paper 10 to the registration unit R.

  In the present embodiment, these intermediate transport rollers 431, 432, and 433 are directly driven by the intermediate transport motor driving unit 430 only for the intermediate transport roller 431 located on the upstream side of the paper feed path, and the other intermediate transport rollers 432. , 433 are driven to rotate by the power transmitted by the belt pulley mechanism.

  The intermediate transport roller group is provided with an intermediate inlet sensor 461 and an intermediate outlet sensor 462. The intermediate inlet sensor 461 is a sensor that is installed in the vicinity of the upstream intermediate conveyance roller 431 in the external paper feed path FR1 and detects the arrival of the printing paper 10 to the external paper feed path FR1. The intermediate outlet sensor 462 is a sensor that is installed in the vicinity of the downstream intermediate conveyance roller 433 in the external paper feed path FR1 and detects the passage of the printing paper 10 from the external paper feed path FR1.

  The paper feed tray 401 is provided with an elevator motor driving unit 410 that moves the paper feed table up and down. The elevator motor driving unit 410 moves the loaded printing paper 10 up and down by transmitting the driving force to the tray bottom plate and moving it up and down under the control of the conveyance driving control unit 450 on the paper feeding side.

  The image forming side conveyance drive control unit 350 (corresponding to the image forming control means in the claims) and the paper feeding side conveyance drive control unit 450 (corresponding to the sheet feeding control means in the claims) A drive circuit or the like that independently controls the path transport operation. Then, by receiving a control signal from the arithmetic processing units 330 and 440 and supplying a current to the target drive unit, the operation start and stop of each drive unit and its operation speed are controlled, and at the time of startup It also controls acceleration, deceleration acceleration during deceleration, and the like.

  Paper feeding in each conveyance path is performed by the arithmetic processing unit 330 and the arithmetic processing unit 440 described above. FIG. 3 is a block diagram showing modules relating to the paper feed control of the arithmetic processing unit 330, the arithmetic processing unit 440 and its peripheral devices, and FIG. 4 is a time chart showing the operation of each drive unit by the paper feed control. The “module” used in the description indicates a functional unit for achieving a predetermined operation, which is configured by hardware such as an apparatus or a device, software having the function, or a combination thereof. .

(1) Internal Configuration of Printing Apparatus 100 As shown in detail in FIG. 4, the arithmetic processing unit 330 of the printing apparatus 100 mainly includes a job data reception unit 331, a paper type acquisition unit 332, and an operation signal acquisition unit 333. A scheduling unit 337, an image processing unit 336, and an operation pattern determination unit 335.

  The job data receiving unit 331 is a communication interface that receives job data that is a series of print processing units, and is a module that passes data included in the received job data to the scheduling unit 337 and the image processing unit 336. The communication here includes, for example, short-range communication such as infrared communication as well as LAN such as intranet (intra-company network) and home network based on 10BASE-T, 100BASE-TX, and the like.

  The image processing unit 336 is an arithmetic processing device that performs digital signal processing specialized for image processing, and is a module that performs conversion of image data necessary for printing and executes printing. The image processing unit 336 includes an image formation control unit 336a and a color conversion circuit 336b.

  The color conversion circuit 336b is a circuit that converts an RGB print image into a CMYK print image, and causes the image formation control unit 336a to execute printing based on the print image for each color. The image formation control unit 336a is a module that controls the operation of the ink heads of each color and the operation of the drive unit of the conveyance path, and controls the entire image formation processing. Perform image formation.

  The operation signal acquisition unit 333 is a module that receives an operation signal from the user from the operation panel 340. The operation signal acquisition unit 333 analyzes the received operation signal and causes another module to execute processing according to the user operation. The paper type acquisition unit 332 is a module that acquires the paper type data such as the size, type, or thickness of the printing paper 10 that is detected by the operation signal acquisition unit 333. Then, the paper type acquisition unit 332 transmits the acquired paper type data to the operation pattern determination unit 335 during the printing process.

  A storage unit 334 is connected to the arithmetic processing unit 330. The storage unit 334 is a memory device that stores various types of data and programs. In the present embodiment, the storage unit 334 stores operation pattern data related to the registration rollers 240a and 240b and the pre-registration rollers 230a and 230b, and print processing is performed. At this time, an operation pattern corresponding to the selected paper size is transmitted to the operation pattern determination unit 335.

  In particular, in the present embodiment, the operation pattern of the pre-registration rollers 230a and 230b is such that the operation speed of the pre-registration rollers 230a and 230b is changed to behaviors such as starting and stopping of the registration rollers 240a and 240b, sudden acceleration, and sudden deceleration. Data for synchronizing and appropriately adjusting the relative speed of the pre-registration rollers 230a and 230b is included. These operation patterns are calculated from the characteristics of the paper feed path including the distance to each drive unit and the length of the printing paper 10 in the transport direction.

  The operation pattern of each drive unit will be described. First, as shown in FIG. 4, the driving of the registration rollers 240a and 240b is started and accelerated at a predetermined timing, and is driven at a predetermined speed until the trailing edge of the sheet comes out of the registration rollers 240a and 240b. It is a pattern (P10).

  Next, the operation pattern of the pre-registration rollers 230a and 230b will be described. The pre-registration rollers 230a and 230b are driven and accelerated at a predetermined timing so that the leading edge of the printing paper 10 reaches the registration rollers 240a and 240b when the registration rollers 240a and 240b are activated (P20).

  In addition, the pre-registration rollers 230a and 230b perform the “butting correction control” deceleration operation at the detection timing (T2) of the registration sensor 501 when the printing paper 10 is delivered to the registration rollers 240a and 240b. (P21). Further, in a section where one sheet of printing paper 10 is gripped between the pre-registration rollers 230a and 230b and the registration rollers 240a and 240b, the pre-registration rollers 230a and 230b are set to the same speed as the rotation speed of the registration rollers 240a and 240b ( P22). Then, at the timing when the next printing paper 10 reaches the pre-registration roller, it is changed to a predetermined speed (P23).

  The scheduling unit 337 analyzes the job data, determines the size and number of sheets for printing, and the presence / absence of double-sided printing. Based on the determination result, the image forming speed and the operating speed, order, and timing of each driving unit are determined. It is a module that determines the transport conditions such as. Based on the schedule determined by the scheduling unit 337, the image formation control unit 336a executes an image forming process, and the conveyance drive control unit 350 and the conveyance drive control unit 450 execute a conveyance operation. The schedule determined by the scheduling unit 337 is also input to the operation pattern determination unit 335.

  The operation pattern determination unit 335 is a module that collates the sheet type data detected by the operation signal acquisition unit 333 and the schedule in the scheduling unit 337 and determines one of the plurality of operation patterns stored in the storage unit 334. is there. In this embodiment, the operation patterns of the registration motor driving unit 240 and the pre-registration motor driving unit 230 are appropriately selected according to the paper size.

  The control signal generation unit 338 (corresponding to the signal output means in the claims) switches the control of each drive unit based on the transport conditions in the scheduling unit 337 and the operation pattern determined by the operation pattern determination unit 335, It is a module that generates a control signal for controlling the operation speed of the drive unit. Specifically, the control signal generation unit 338 determines whether the operation speed of each driving unit starts or stops driving the registration rollers 240a and 240b, or accelerates or decelerates according to the determined operation pattern and scheduling. In order to synchronize with each other, a signal for controlling the timing of starting and stopping the other driving units is generated, and a signal for controlling the conveyance speed of the printing paper 10 at each point of each driving unit is generated.

  Here, regarding the registration rollers 240a and 240b and the pre-registration rollers 230a and 230b installed on the printing apparatus 100 side, the control signal generation unit 338 relates to the start timing and the conveyance speed according to the schedule and the operation pattern. A data signal is generated and sent to the transport drive controller 350. In response to the control signal, the conveyance drive control unit 350 drives the registration motor driving unit 240 and the pre-registration motor driving unit 230 so as to execute sheet feeding control according to the schedule and the operation pattern.

  On the other hand, regarding the pickup roller 420a, the scraper roller 420b, and the intermediate transport rollers 431, 432, and 433 installed on the paper feeding device 400 side, the control signal generation unit 338 is associated with the pickup motor driving unit 420. And a signal indicating the operation timing of the intermediate transport motor drive unit 430 is generated as a paper feed reference signal and transmitted to the transport drive control unit 450 of the paper feed device 400.

  As shown in FIG. 4, the paper feed reference signal is a rectangular wave pulse signal obtained by alternately combining a low voltage pulse falling at the first timing and a high voltage pulse rising at the second timing. In this embodiment, the operation timings of the pickup motor driving unit 420 and the intermediate conveyance motor driving unit 430 are individually controlled based on the change of the signal to the Low voltage pulse or the High voltage pulse. Specifically, the control signal generation unit 338 changes the signal from the high voltage pulse to the low voltage pulse at the timing of starting the pickup roller 420a, the scraper roller 420b, and the intermediate transport rollers 431, 432, and 433.

  The timing for changing the paper feed reference signal is the time when the registration rollers 240a and 240b are activated so that the leading edge of the printing paper 10 reaches the registration rollers 240a and 240b when the registration rollers 240a and 240b are activated. , Calculated from the conveyance distance of the external paper feed path FR1 and the registration unit R, and the paper size. On the other hand, the control signal generation unit 338 changes the signal from the low voltage pulse to the high voltage pulse at the timing of starting the deceleration operation of the “butting correction control” of the intermediate transport rollers 431, 432, and 433. The timing for changing the paper feed reference signal is executed based on detection by the registration sensor 501. As described above, the control signal generation unit 338 generates the paper feed reference signal changed to the Low voltage pulse or the High voltage pulse at each timing, and transmits the paper feed reference signal to the arithmetic processing unit 440 of the paper feeding device 400.

(Internal configuration of paper feeding device 400)
As illustrated in FIG. 4, the sheet feeding device 400 includes an arithmetic processing unit 440, a conveyance drive control unit 450, and a storage unit 470.

  The storage unit 470 (corresponding to the storage means in the claims) is a memory device that stores and holds various data and programs. In the present embodiment, the above-described pickup roller 420a, scraper roller 420b, and intermediate transport Operation pattern data relating to the rollers 431, 432, and 433 is stored. In this embodiment, this operation pattern includes the operation speeds of the intermediate transport rollers 431, 432, 433, the pickup roller 420a, and the scraper roller 420b, the start and stop of driving of the registration rollers 240a and 240b, sudden acceleration and sudden deceleration. The data which adjusts the relative speed of each drive part appropriately in synchronism with such behaviors are included. These operation patterns are calculated from the characteristics of the paper feed path including the distance to each drive unit and the length of the printing paper 10 in the transport direction.

  As shown in FIG. 4, the operation pattern of the pickup roller 420a and the scraper roller 420b is as follows. First, the pickup roller 420a and the scraper roller 420b are activated and accelerated at the falling timing T1 of the paper feed reference signal (P30). After the entrance sensor 461 detects the leading edge of the printing paper 10, it stops (P31) and starts driving again at the next predetermined timing. The operation patterns of the intermediate transport rollers 431, 432, and 433 are driven and accelerated simultaneously with the pickup roller 420a and the scraper roller 420b at the falling timing T1 of the paper feed reference signal (P40), and the intermediate transport rollers 431, 432, and 433 are driven. The transfer speed from the pre-registration rollers 230a and 230b to the pre-registration rollers 230a and 230b is set to the same speed level as the pre-registration rollers 230a and 230b (P41).

  Further, in the section where one sheet of printing paper 10 is connected between the intermediate conveyance rollers 431, 432, 433 and the pre-registration rollers 230a, 230b, the intermediate conveyance rollers 431, 432, 433 are rotated at the rotational speeds of the pre-registration rollers 230a, 230b. (P42). In the section where the printing paper 10 is gripped by the registration rollers 240a and 240b, the intermediate transport rollers 431, 432 and 433 are set to the same speed as the rotation speed of the registration rollers 240a and 240b (P43). Further, after the trailing edge of the printing paper 10 is removed from the intermediate conveyance rollers 431, 432, 433, the rotation speeds of the intermediate conveyance rollers 431, 432, 433 are equal to the rotation speeds of the pickup roller 420a and the scraper roller 420b. (P44).

  The arithmetic processing unit 440 (corresponding to the signal input unit in the claims) switches the control of each driving unit on the paper feeding device 400 side based on the paper feeding reference signal transmitted from the control signal generating unit 338, and drives each driving This module controls the overall operation of the unit. Specifically, the arithmetic processing unit 440 determines the motor drive units 410, 420, and 430 to be driven according to the change in the paper feed reference signal, and stores the operation pattern for the motor drive units 410, 420, and 430 in the storage unit 470. And send these data to the conveyance drive control unit 450 on the paper feed side.

  Based on the control of the arithmetic processing unit 440, the transport drive control unit 450 executes drive control in the external paper feed path FR1 while referring to the operation pattern so as to execute paper feed control according to the schedule. The roller 420a, the scraper roller 420b, and the intermediate transport rollers 431, 432, and 433 are driven. Specifically, when the transmitted paper feed reference signal changes from a high voltage pulse to a low voltage pulse, as shown in FIG. 4, a pickup roller 420a, a scraper roller 420b, and intermediate transport rollers 431, 432, 433 is activated (P30, P40). On the other hand, when the transmitted paper feed reference signal changes from the Low voltage pulse to the High voltage pulse, as shown in FIG. 4, the intermediate conveyance rollers 431, 432, and the like are synchronized with the operation of the pre-registration rollers. 433 is decelerated in synchronization with the decelerating operation of the pre-registration roller (P42).

(Paper control operation)
The operation of the paper feed control mechanism having the above configuration will be described. FIG. 5 is a flowchart showing the operation of the conveyance speed control. Here, a case where job data for performing a printing process using the printing paper 10 in the paper feeding device 400 is input to the printing apparatus 100 will be described as an example. In addition, it is assumed that the storage unit 470 of the sheet feeding device 400 stores operation patterns of the pickup motor driving unit 420 and the intermediate conveyance motor driving unit 430 in advance.

  As shown in FIG. 5, first, when job data reception unit 331 receives job data (step S <b> 101), these job data are sent to scheduling unit 337.

  The scheduling unit 337 analyzes the job data, determines the size and number of sheets for printing, and the presence / absence of double-sided printing. Based on the determination result, the image forming speed and the operating speed, order, and timing of each driving unit are determined. The conveyance conditions such as the above are determined (step S102), and information on the conveyance conditions is sent to the operation pattern determination unit 335. The operation pattern determination unit 335 first determines the operation patterns and operation timings of the registration rollers 240a and 240b on the printing apparatus 100 side based on the scheduling transport conditions. Based on the operation pattern and scheduling of the registration rollers 240a and 240b, the operation pattern determination unit 335 starts and stops driving the registration rollers 240a and 240b, suddenly accelerates and decelerates, and the like. The operation pattern of the other drive unit is determined so as to be synchronized with the behavior of the other drive unit.

  Thereafter, information on the conveyance conditions and the operation pattern is input to the control signal generation unit 338, and the control signal generation unit 338 generates a signal for controlling the conveyance speed of the printing paper 10 at each point of each driving unit. Specifically, the control signal generation unit 338 first, based on the operation timing information of the registration rollers 240a and 240b, the leading edge of the printing paper 10 reaches the registration rollers 240a and 240b at the timing when the registration rollers 240a and 240b are activated. Thus, the timing for starting the pickup roller 420a, the scraper roller 420b, and the intermediate transport rollers 431, 432, and 433 is calculated. Then, based on the calculated result, the paper feed reference signal is changed from the high voltage pulse to the low voltage pulse at a predetermined timing, and is transmitted to the arithmetic processing unit 440 of the paper feed device 400 (step S103).

  When the arithmetic processing unit 440 detects the falling edge of the paper feed reference signal, the arithmetic processing unit 440 determines to activate the pickup motor driving unit 420 and the intermediate conveyance motor driving unit 430 and operates according to the paper size from the storage unit 470. The pattern is determined, and the information is transmitted to the conveyance drive control unit 450 on the paper feeding side.

  In the conveyance drive control unit 450, the pickup motor drive unit 420 and the intermediate conveyance motor drive unit 430 are driven to drive the pickup motor drive unit 420 and the intermediate conveyance motor drive unit 430 in order to perform sheet feeding control according to the schedule. The pickup roller 420a, the scraper roller 420b, and the intermediate transport rollers 431, 432, and 433 are rotated (step S104). Thereafter, the pickup roller 420a and the scraper roller 420b are stopped after the intermediate entrance sensor 461 detects the leading edge of the printing paper 10.

  On the other hand, the pre-registration rollers 230a and 230b start to start when the leading edge of the printing paper 10 passes the downstream intermediate conveyance roller 433 (step S105), and print at the same speed as the conveyance speed of the intermediate conveyance roller 433. Accept paper 10. Thereafter, when the registration sensor 501 detects the arrival of the printing paper 10 (step S106), the control signal generation unit 338 causes the pre-registration rollers 230a and 230b to start the deceleration operation of the “butting correction control”. Is input to the conveyance drive control unit 350, and the pre-registration rollers 230a and 230b perform a deceleration operation of “abutting correction control” in step S109. At this time, the control signal generation unit 338 changes the paper feed reference signal from the Low voltage pulse to the High voltage pulse, and transmits the signal to the arithmetic processing unit 440 of the paper feed device 400 (Step S107).

  When the arithmetic processing unit 440 detects the rising edge of the paper feed reference signal that has changed from the Low voltage pulse to the High voltage pulse, the intermediate conveyance rollers 431, 432, and 433 are synchronized with the operations of the pre-registration rollers 230a and 230b. The "bump correction control" is decelerated (step S108).

  Thereafter, when a predetermined time is reached, the registration rollers 240a and 240b start to rotate while holding the printing paper 10 (step S110), and convey the printing paper 10 to the head unit 110. Next, the control signal generation unit 338 refers to the schedule information and determines whether or not the print job has ended (step S111). If the print job has not ended (NO in step S111), the processing from step S103 to step S110 is repeated for the next print sheet 10. If the print job is finished (YES in step S111), the operation is finished.

(Action / Effect)
According to the present embodiment, the sheet feeding reference signal for notifying the timing at which the pre-registration rollers 230 a and 230 b start the deceleration operation of the “butting correction control” is sent through the single signal line 20. To the side. When the paper feed device 400 receives the paper feed reference signal, the intermediate transport rollers 431, 432, and 433 are moved to the pre-registration rollers 230a and 230b based on the operation pattern stored in the storage unit 470. It is driven in the same way as the deceleration operation of “Bump Correction Control”.

  For this reason, the intermediate conveyance rollers 431, 432, and 433 and the pre-registration rollers 230a and 230b can have the same conveyance speed when the single printing paper 10 is gripped. As a result, the occurrence of back tension can be prevented, and the image forming process can be speeded up. Furthermore, according to the present embodiment, the printing apparatus 100 side can synchronize the operations of the drive units of the printing apparatus 100 and the paper feeding apparatus 400 by transmitting only the timing signal for starting the operation. By reducing the number of signal lines 20 connecting the printing apparatus 100 and the paper feeding apparatus 400, the entire apparatus can be reduced in size and the manufacturing cost can be reduced.

  Further, according to the present embodiment, the control signal generation unit 338 changes the paper feed control signal from the high voltage pulse to the low voltage pulse based on the detection by the registration sensor 501, and is calculated from the operation of the registration rollers 240a and 240b. The low voltage pulse is changed to the high voltage pulse at a predetermined timing. Then, the paper feed control signal changed to the high voltage pulse or the low voltage pulse is transmitted to the paper feed device 400 side.

  Upon receipt of this paper feed reference signal, the paper feed side transport drive controller 450 starts and accelerates the pickup roller 420a, scraper roller 420b, and intermediate transport rollers 431, 432, and 433 at the fall of the paper feed reference signal. When the paper feed reference signal rises, the operations of the intermediate transport rollers 431, 432, and 433 are synchronized with the deceleration operation of the “butting correction control” by the pre-registration rollers 230a and 230b.

  As described above, in this embodiment, the operation of different driving units is individually performed by the rise or the fall of the 2-bit single timing signal (paper feed reference signal) that changes to the High voltage pulse or the Low voltage pulse. Can be synchronized. This reduces the number of connection ports of the signal line 20 and the printing apparatus 100 and paper feeding apparatus 400 necessary for the connection, thereby reducing the size of the entire system, reducing the specifications of the control unit by reducing the number of connection ports, and manufacturing. Cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Printer system 10 Printing paper 20 Signal line 100 Printing apparatus 110 Head unit 120 Opening 130 Paper feed tray 140 Paper discharge port 150 Paper discharge stand 160 Conveying belt 161 Drive roller 162 Driven roller 170 Switching mechanism 172 Switching mechanism 214 Junction point 230 Before registration Motor drive unit 230a, 230b Roller before registration 240 Registration motor drive unit 240a, 240b Registration roller 330 Arithmetic processing unit 331 Job data receiving unit 332 Paper type acquisition unit 333 Operation signal acquisition unit 334 Storage unit 335 Operation pattern determination unit 336 Image processing unit 336a Image formation control unit 336b Color conversion circuit 337 Scheduling unit 338 Control signal generation unit 340 Operation panel 350 Transport drive control unit 400 Paper feed device 401 Paper feed tray 410 Elevate Motor drive unit 420 Pickup motor drive unit 420a Pickup roller 420b Scraper roller 430 Intermediate transport motor drive unit 431, 432, 433 Intermediate transport roller 440 Arithmetic processing unit 450 Transport drive control unit 461 Intermediate entrance sensor 462 Intermediate exit sensor 470 Storage unit 501 Resist Sensor CR Normal path DR Paper discharge path FR Paper feed path FR1 External paper feed path R Registration section SR Reverse path

Claims (4)

Image forming apparatus for receiving a recording medium supplied from a sheet feeding device that conveys a recording medium picked up by a pickup roller from a sheet feeding tray by an intermediate conveying roller group and forming an image on the recording medium while conveying the recording medium on a conveying path Because
A registration roller that adjusts the delivery timing of the received recording medium with respect to the transport path;
A pre-registration roller for feeding the recording medium received from the paper feed path to the registration roller;
A registration sensor that detects the recording medium on the upstream side of the registration roller in the conveyance direction of the recording medium;
Image forming control means for controlling the operation of the pre-registration roller based on the detection timing of the recording medium by the registration sensor;
Supply that alternately repeats signal level changes at a first timing at which the pickup roller picks up the recording medium and a second timing at which the intermediate conveyance roller group starts to synchronize operation with the pre-registration rollers. A signal output means for outputting a paper reference signal to the paper feeding device;
An image forming apparatus comprising: The image formation control means
The pre-registration roller is decelerated to a predetermined speed by a predetermined deceleration pattern for a predetermined period from the second timing until the stopped registration roller resumes rotation, and at least until the first timing. Rotating in synchronization with the registration roller;
The image forming apparatus according to claim 1. A sheet feeding device having a sheet feeding path for supplying a recording medium conveyed from a pre-registration roller of an image forming apparatus to a conveyance path via a registration roller, to the image forming apparatus,
A pickup roller for picking up the recording medium to the paper feed path;
An intermediate conveyance roller group for conveying the recording medium picked up by the pickup roller on the paper feed path;
A signal level at a first timing at which the intermediate conveyance roller group finishes rotating in synchronization with the pre-registration roller and at a second timing at which the intermediate conveyance roller group starts rotation in synchronization with the pre-registration roller. A signal input means for inputting a paper feed reference signal supplied from the image forming apparatus, wherein the change is repeated alternately;
Storage means for storing a rotation pattern of the pre-registration roller from the second timing to the first timing;
Paper feed control means for controlling operations of the pickup roller and the intermediate transport roller group based on the paper feed reference signal and the rotation pattern of the storage means;
A sheet feeding device comprising: The paper feed control means
Rotating the pickup roller to pick up the recording medium at the first timing;
Based on the rotation pattern of the storage means, the intermediate transport roller group is synchronized with the pre-registration roller for a predetermined period from the second timing until the stopped registration roller resumes rotation. After decelerating to a predetermined speed by a deceleration pattern, rotate at least until the first timing in synchronization with the registration roller,
The sheet feeding device according to claim 3.

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