JP2009300945A - Image forming system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming system capable of measuring and identifying the type of a recording medium with high accuracy by synchronizing an image forming apparatus and an extension paper feeder, thereby stabilizing the position of the recording medium being conveyed. <P>SOLUTION: In the recording medium measurement mode of a recording medium identifying means 118 in the image forming system including the image forming apparatus 100 for forming a toner image on a recording medium by an electrophotographic process and the extension paper feeder 200 extension-connectable to the image forming apparatus, the image forming system synchronizes the operation timing of a first conveying means 66 and the operation timing of a second conveying means 209 by use of a synchronizing means 208 when the recording medium 207 is fed and conveyed from the extension paper feeder to the image forming apparatus, the first conveying means 66 being installed in the image forming apparatus and used for recording medium conveyance and the second conveying means being installed in the extension paper feeder and used for recording medium conveyance. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming system that can determine the type of a recording medium with high accuracy.

(1) Example of Conventional Image Forming Apparatus Hereinafter, an example of a conventional configuration of an image forming apparatus according to the present invention will be described.

  FIG. 8 is a diagram illustrating the configuration of the image forming apparatus 100 and the extended sheet feeding apparatus 200. In the image forming apparatus 100 shown in FIG. 8, four image forming units are arranged for each color of yellow (Y), magenta (M), cyan (C), and black (Bk).

  Each of the image forming units includes image carriers 101Y to 101Bk and charging units 102Y to 102Bk for uniformly charging the image carriers to a predetermined potential.

  Further, laser scanner units 104Y to 104Bk for forming electrostatic latent images by irradiating the charged image carrier with laser beams 103Y to 103Bk corresponding to the respective color image data, and developing the electrostatic latent images. Developing means 105Y to 105Bk for visualizing are provided.

  Further, sleeve rollers 106Y to 106Bk for sending the color toners in the developing means 105Y to 105Bk to the image carrier, and transfer means 108Y to 108Bk for transferring the toner image formed on the image carrier to the transfer belt 113 are provided. Have. Further, cleaning units 109Y to 109Bk for removing toner remaining on the image carrier after transfer of the toner to the transfer belt are provided, and 110Y to 110Bk are waste toner units for storing waste toner.

  The image forming apparatus 100 has a paper feeding unit at the bottom, and a paper feeding cassette 111 in which the recording medium 107 is stored. In addition, a pickup roller 112 for feeding the recording medium and the leading end of the recording medium 107 are detected in the conveyance path of the recording medium 107 from the paper feeding cassette 111, and the transfer timing is determined at the transfer position with the transfer belt 113. The transport sensor 114 is arranged. Further, a registration roller 115 is provided for waiting the recording medium 107 in order to take a timing for secondary transfer of the toner image primarily transferred onto the transfer belt 113 onto the recording medium 107.

  The recording medium 107 is fed by a conveyance motor (not shown) disposed in the sheet feeding unit and a solenoid that connects the conveyance motor and a paper feeding gear in accordance with the sheet feeding timing. The toner image is secondarily transferred to the fed recording medium 107 at the position of the secondary transfer roller 116. A fixing unit 117 melts and fixes the four color toner images transferred onto the recording medium 107. The fixed recording medium 107 is discharged outside the apparatus, and the image forming operation is finished.

  As other functions (not shown) in the paper feeding unit, a recording medium presence / absence detection sensor for detecting whether or not the recording medium 107 is loaded on the paper feeding cassette 111, and a sheet of the recording medium 107 loaded on the paper feeding cassette. A recording medium size detection sensor for detecting the size is provided. Also, a lift-up mechanism that raises and lowers the recording medium 107 loaded in the paper feed cassette 111 to a predetermined paper feed port height, a paper surface position detection sensor that detects the height position of the recording medium 107 raised by the lift-up mechanism, and the like It is common to have.

(2) Example of Extended Paper Feed Device The conventional image forming apparatus shown in FIG. 8 generally has a case in which the extended paper feed device 200 is connectable for a user who handles a large variety of recording paper. is there. The extended sheet feeder 200 can be described in the same manner as the configuration of the sheet feeder section of the image forming apparatus 100. That is, in the conveyance path of the recording medium 207 from the sheet feeding cassette 211, the pickup roller 212 for feeding the recording medium and the leading end of the recording medium 207 are detected, and the delivery timing to the image forming apparatus 100 is achieved. A conveyance sensor 214 is included. In addition, a registration roller 215 for placing the recording medium 207 on standby in order to take delivery timing to the image forming apparatus 100 is provided.

  The recording medium 207 is fed by a conveyance motor (not shown) disposed in the extended sheet feeding device 200 and a solenoid that connects the conveyance motor and a paper feeding gear in accordance with the sheet feeding timing. The fed recording medium 207 is transported into the image forming apparatus 100 after being sent out from the extended sheet feeding apparatus 200, and is transported in common with the sheet feeding apparatus on the image forming apparatus 100 side after passing through the registration roller 115. Follow the path. The toner image is transferred at the position of the secondary transfer roller 116, and the recording medium 207 fixed by the fixing device 117 is discharged out of the apparatus.

  Similar to the paper feeding unit of the image forming apparatus 100, the extended paper feeding device 200 has a recording medium presence / absence detection sensor for detecting whether a recording medium is loaded on the paper feeding cassette, and a recording medium loaded on the paper feeding cassette. A recording medium size detection sensor for detecting the size of the paper. Also, a lift-up mechanism that raises and lowers the recording medium 207 loaded in the paper feed cassette 211 to a predetermined paper feed port height, a paper surface position detection sensor that detects the height position of the recording medium 207 raised by the lift-up mechanism, and the like have.

  The image forming apparatus 100 can issue an operation instruction to the extended sheet feeding apparatus 200 through communication control.

  In a conventional image forming apparatus, a form in which the image forming apparatus and the extended sheet feeding apparatus are connected by a serial interface is often employed.

  FIG. 9 shows a configuration of a serial interface between the conventional image forming apparatus 100 and the extended sheet feeding apparatus 200.

  In FIG. 9, reference numeral 61 denotes an engine controller of the image forming apparatus 100, 62 denotes an engine CPU of the image forming apparatus 100, and 201 denotes a controller (referred to as an optional controller) of the extended sheet feeding apparatus 200. 202 is a CPU (referred to as an option CPU) of the extended sheet feeder, 203 is a clock signal (abbreviated as CLK), 204 is a command signal (abbreviated as CMD), and 206 is a status signal (abbreviated as STS). Yes, the serial interface consists of these three. Reference numeral 205 denotes a signal line from which the CMD 204 is branched inside the option controller 201, and is connected to an interrupt port of the option CPU 202.

  When the image forming apparatus and the extended paper feeder are connected via a serial interface, when the paper feed motor of the extended paper feeder is started or a paper feed operation is performed, a serial command corresponding to each operation is sent to the engine controller 61. Produces. Then, the option controller 201 that transmits to the option controller 201 using the serial interface and receives the serial command analyzes the command and performs an operation based on the analyzed result.

  In addition, when the engine controller needs information on the extended paper feeder, for example, whether or not paper is detected by a sensor on the paper feed conveyance path, the engine controller generates a serial command for requesting sensor information. To the option controller. Upon receiving the command, the option controller 201 analyzes the command and, when recognizing that the command is a serial command requesting sensor information, transmits the sensor state to the engine controller 61 via the serial interface.

(3) Example of media sensor As a method for discriminating a recording medium in a conventional image forming apparatus, there is one in which a media sensor is arranged. The image forming apparatus 100 shown in FIG. 8 includes a media sensor 118 at a position between the registration roller 115 and the secondary transfer roller 116, and irradiates the surface of the recording medium fed / conveyed from the paper feed cassette 111 with light. I am letting. Then, the reflected light is condensed and imaged, and the recording medium is discriminated by detecting an image of a specific area of the recording medium.

  An example of the configuration of the media sensor 118 described above is shown in FIG. In FIG. 10, reference numeral 801 denotes an LED as a light irradiation means, 802 denotes an imaging device as an image reading means, 803 denotes a condenser lens, and 804 denotes an imaging lens. Light using the LED 801 as a light source is applied to the surface of the recording medium conveyance guide (not shown) or the surface of the recording medium 107 on the recording medium conveyance guide via a condenser lens 803.

  The reflected light from the recording medium 107 is collected via the imaging lens 804 and imaged on the image sensor 802. Thus, the surface image of the recording medium conveyance guide or the recording medium 107 is read. Note that the LED 801 is arranged so that the LED light irradiates light obliquely with a predetermined angle with respect to the surface of the recording medium 107.

  Reference numeral 805 denotes an LED unit disposed at a position opposite to the media sensor 118 and the recording medium, and reference numeral 806 denotes a transmitted light LED for irradiating light from the back side of the recording medium (the LED 801 is a reflected light LED). It is. Reference numeral 807 denotes a condensing lens for condensing the irradiation light from the transmitted light LED 806 and emits light to the back surface of the recording medium.

  Reference numeral 808 denotes a conveyance guide member for the recording medium. In the configuration example described, a window for irradiating light from the back side of the recording medium is provided. Reference numeral 811 denotes a light diffusion plate represented by a polyacetal resin (POM) material or the like. The light diffusing plate 811 is provided on the side facing the media sensor 118 through the recording medium and at a position between the recording medium and the LED unit 805.

  FIG. 11 is a diagram illustrating the relationship between the surface of the recording medium read by the image sensor 802 of the media sensor 118 and an example in which the output from the image sensor 802 is digitally processed to 8 × 8 pixels.

  The digital processing is performed by converting the analog output from the image sensor 802 into, for example, 8-bit pixel data by A / D conversion (not shown) as conversion means.

  In FIG. 11, reference numeral 50 denotes an enlarged image of the surface of the recording paper A, which is a so-called rough paper in which the fibers of the target paper are relatively loose, and 51 is a recording paper B, which is a commonly used so-called plain paper. This is an enlarged image of the surface. Reference numeral 52 denotes an enlarged image of the surface of the recording paper C, which is a glossy paper in which the paper fibers are sufficiently compressed. These images 50 to 52 read into the image sensor 802 are digitally processed into images 53 to 55 shown in the figure.

  Thus, the image on the surface varies depending on the type of the recording medium. This is a phenomenon that occurs mainly because the fiber state on the surface of the recording medium is different.

  As described above, the image that has been read from the surface of the recording medium by the image sensor 802 and digitally processed can be discriminated by the surface state of the paper fibers of the recording medium.

  Further, the media sensor 118 arranges an LED for transmitted light on the side facing through the recording medium, and determines the basis weight (paper thickness) of the recording medium by detecting the transmitted light amount.

  When the light diffusing plate 811 irradiates light from the LED unit 805 on the lower side, the upper side of the light diffusing plate 811 can be viewed as a surface light source of light made uniform by the diffusing plate. For this reason, the LED unit 805 does not cause the light emission image of the LED 806 to directly enter the image sensor 802 with respect to the image sensor 802. Since it is not affected by the luminescent image, the output level difference can be detected even when discriminating between OHT sheets and thin paper.

Accordingly, plain paper, an OHT sheet, and glossy paper (gloss paper) can be discriminated from the reflected light information from the recording medium irradiated from the LED 801 because the surface smoothness of the recording medium is used. And from the transmitted light information from the recording medium irradiated from LED806, thin paper (basis weight ~ 64g / m < ² >), plain paper (basis weight 65-105g / m < ² >), thick paper 1 (basis weight 106-160g / m < ² >). ), Cardboard 2 (basis weight 161-300 g / m ² ) can be discriminated.

  FIG. 12 shows control blocks performed by the recording medium detected from the media sensor 118 as described above. In FIG. 12, 60 is a controller that transmits a print signal to the engine portion of the image forming apparatus in accordance with an instruction from the host computer, and 61 is an engine controller that controls the engine portion of the image forming apparatus. 62 is a CPU that controls each operation block of the image forming apparatus, 63 is a fixing control unit that supplies electric power to the fixing device 117 according to an instruction from the engine CPU 62, and 64 is a driving unit of the image forming apparatus according to an instruction from the engine CPU 62. It is a drive control part which performs control. Reference numeral 65 denotes a drive unit related to image formation of the image forming apparatus. The drive control unit 64 and the drive unit 65 are composed of a plurality of units such as a normal paper feed / conveyance unit, an image forming unit, a fixing / discharge unit, but are collectively described as a drive unit in the description of the present invention.

  In the above configuration, when a print signal is transmitted from the controller 60, the engine CPU 62 starts feeding the recording medium. The media sensor 118 determines the paper type of the recording medium at a position where the recording medium has stopped before the registration roller. In accordance with the discriminated paper type, an optimum fixing temperature target value and conveyance speed are set, and instructions are sent to the fixing control unit 63 and the drive control unit 64, respectively. Each control unit performs conveyance and fixing based on a predetermined set value in accordance with an instruction from the engine CPU 62, and is discharged from the image forming apparatus.

For example, Patent Document 1 discloses an image forming apparatus in which a large number of paper feed cassettes can be set and the type of paper feed cassette can be freely selected without being restricted by the number of connection ports.
JP-A-5-69988

  In an image forming apparatus equipped with the media sensor described in the above conventional example, when detecting a normal recording medium, several points (approximately approximately) on the recording medium are considered in consideration of variations in surface unevenness and light transmission on the recording medium. 6-10 points) data is sampled and calculated. Since the image read at each sampling point is calculated, the calculation processing time may be slower than the sheet passing speed of the recording medium. In this case, the sheet passing speed (throughput) must be reduced when the recording medium is detected. Further, since the media sensor reads the surface image of the recording medium, it is desirable that the recording medium is in a stationary state when the surface image is read.

  However, the recording medium fed / conveyed from the extended paper feeder is sent from the extended paper feeder to the image forming apparatus, and both the extended paper feeder and the image forming apparatus are used when the media sensor measures the recording medium. The recording medium is sandwiched between the conveying rollers. For this reason, when there is a speed difference between the conveying roller peripheral speeds (drive motor speeds) of both the extension paper feeding device and the image forming apparatus, or when the drive timing is shifted, the posture in which the recording medium is pushed into the image forming apparatus side, the image The forming apparatus is in a posture of pulling the recording medium. In such a state, since the posture of the recording medium with respect to the media sensor is slightly tilted or deviated from the measurement point, stable and highly accurate measurement is not expected.

  Due to the above-described problems, the drive motor of the image forming apparatus and the drive motor of the extended sheet feeding apparatus are normally controlled to be driven at the same speed. However, the conventional extended sheet feeder is controlled by serial communication from the image forming apparatus, and needs to transmit and receive various amounts of information. For this reason, there is a possibility that information to be sequentially communicated may be delayed depending on the time required for transmission / reception and the time for re-transmission / reception of data when a communication error occurs. Since such a delay occurs, it is difficult to always keep the speeds of the drive motor of the image forming apparatus and the drive motor of the extension sheet feeding device constant.

  In view of this, the present invention improves the above-described problems, stabilizes the posture of the recording medium being conveyed by synchronizing the conveyance of the image forming apparatus and the extended sheet feeding apparatus, and performs highly accurate recording medium type determination measurement. An object of the present invention is to provide an image forming system capable of performing the above.

  In order to achieve the above-mentioned object, the present invention comprises the following configurations (1) to (3).

  (1) In an image forming system including an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and an extended sheet feeding apparatus that can be expanded and connected to the image forming apparatus, the image forming apparatus is controlled. First control means for controlling, the second control means for controlling the extended paper feeding apparatus, a first transport means installed in the image forming apparatus for transporting a recording medium, and in the extended paper feeding apparatus A second conveying means for conveying a recording medium installed on the serial communication means, a serial communication means for performing communication and control between the first control means and the second control means, and the first conveying means. Synchronization means for matching the operation timing of the means and the operation timing of the second transport means, and a recording medium discrimination means for discriminating the type of the recording medium, in the recording medium measurement mode of the recording medium discrimination means, When the recording medium is fed and transported from the extended sheet feeding device to the image forming apparatus, the synchronization unit synchronizes the operation timing of the first conveyance unit and the operation timing of the second conveyance unit. An image forming system.

  (2) In an image forming system comprising an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and a plurality of expansion paper feeding apparatuses that can be extendedly connected to the image forming apparatus, the image forming apparatus A first control unit that controls the operation of the plurality of expansion sheet feeding devices, a first transport unit that is installed in the image forming apparatus and transports the recording medium. A plurality of conveying units installed in the plurality of extended sheet feeders for conveying a recording medium, and a serial for sequentially communicating and controlling between the image forming apparatus and the plurality of extended sheet feeders. A communication means; a synchronization means for matching the operation timing of the first conveying means and the operation timing of the plurality of conveying means; and a recording medium determining means for determining the type of the recording medium. When the recording medium is fed and conveyed from any one of the plurality of extended sheet feeding devices to the image forming apparatus in the recording medium measurement mode of the determination unit, the operation of the first conveyance unit is performed by the synchronization unit. An image forming system characterized in that a timing is synchronized with an operation timing of the plurality of conveying means.

  (3) Operation of the image forming apparatus in an image forming system including an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and an extended sheet feeding apparatus that can be expanded and connected to the image forming apparatus A first control unit for controlling the operation, at least one control unit for controlling the operation of the extended sheet feeding device, a first transport unit that is installed in the image forming apparatus and transports a recording medium, At least one conveying unit installed in the extended sheet feeding device for conveying a recording medium; a serial communication unit for performing communication and control between the image forming apparatus and the extended sheet feeding device; A synchronization means for matching the operation timing of the first transport means and the operation timing of the at least one transport means, and a recording medium determination means for determining the type of the recording medium, In the recording medium measurement mode of the recording medium determining unit, when the recording medium is fed and conveyed from any one of the conveying units in the extended sheet feeding device to the image forming apparatus, the first synchronizing unit performs the first recording. An image forming system characterized in that an operation timing of a conveying unit and an operation timing of at least one conveying unit of the extended sheet feeder are synchronized.

  According to the image forming apparatus of the present invention, in the first aspect, when the recording medium is fed / conveyed from the extended sheet feeding device in the recording medium measurement mode, the first conveying unit and the second conveying unit are synchronized by the synchronizing unit. The start and stop timings of the second transfer means are matched by synchronizing the transfer means. As a result, it is possible to avoid a delay in serial communication between the first control unit in the image forming apparatus and the second control unit in the expansion sheet feeding device and to stabilize the posture during conveyance of the recording medium. There is an effect that leads to improvement in detection accuracy in the type discrimination measurement of the recording medium.

  In the second aspect of the invention, when the recording medium is fed / conveyed from any one of the plurality of extended sheet feeding apparatuses in the recording medium measurement mode, the first conveying unit and the plurality of conveying units are synchronized by the synchronizing unit. Synchronize and synchronize the start and stop timings of multiple transport means. As a result, it is possible to avoid a delay in serial communication between the first control unit of the image forming apparatus and the plurality of control units of the plurality of extension paper feeding apparatuses and to stabilize the posture during conveyance of the recording medium. This has the effect of improving the detection accuracy in the type discrimination measurement of the recording medium.

  In the third aspect of the invention, in the recording medium measurement mode, when the recording medium is fed / conveyed from any one of the conveying means in the extended sheet feeding device, at least one or more of the first conveying means is synchronized by the synchronizing means. The start and stop timings of the plurality of transfer means are matched by synchronizing the transfer means. As a result, it is possible to avoid a delay in serial communication between the first control unit of the image forming apparatus and at least one control unit in the expansion sheet feeding device and to stabilize the posture during conveyance of the recording medium. This has the effect of improving detection accuracy in medium type discrimination measurement.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

<Configuration of image forming system>
FIG. 1 is a diagram illustrating a configuration of an image forming system including an image forming apparatus using an electrophotographic process according to a first embodiment of the present invention and an extended sheet feeding apparatus that can be expanded. In the description of the configuration of the present embodiment, the detailed description of the reference numerals described above is omitted. With respect to the recording medium measurement mode described in the present embodiment, the recording medium is fed and conveyed from the extended sheet feeding apparatus, and the recording medium is measured by the media sensor 118 installed in the image forming apparatus 100. To do. The media sensor 118 is a recording medium discrimination unit.

  In FIG. 1, 61 is an engine controller that controls the engine portion of the image forming apparatus 100, and 62 is a CPU (referred to as an engine CPU) that controls each operation block of the image forming apparatus 100. Reference numeral 66 denotes a motor driving unit that drives and controls the motor of the paper feeding / conveying unit of the image forming apparatus 100 according to an instruction from the engine CPU 62, and 120 denotes a motor of the paper feeding / conveying unit of the image forming apparatus 100.

  201 is the above-described option controller, 202 is the above-described option CPU, 203 is a clock signal (abbreviated as CLK), 204 is a command signal (abbreviated as CMD), and 206 is a signal of a status signal (abbreviated as STS). Is a line. The serial communication interface is composed of three lines, CLK, CMD, and STS. Reference numeral 205 denotes an interrupt signal line from which the CMD 204 is branched inside the option controller 201, and is connected to an interrupt port of the option CPU 202. The interrupt port of the option CPU 202 to which the CMD interrupt signal line 205 is connected is a level interrupt, and an interrupt is generated when the signal becomes a LOW level.

  Reference numeral 208 denotes a signal line of a timing signal (abbreviated as TMG) for instructing an operation timing in order to synchronize the control target controlled by the option CPU from the engine CPU. This signal line is assumed to be electrically connected between the engine CPU and the option CPU by a general-purpose input / output terminal. Reference numerals 209 and 209 denote motor driving units 1 and 210 that drive and control the motors of the sheet feeding / conveying unit of the expansion sheet feeding device in accordance with instructions from the option CPU.

  Reference numeral 214 denotes a conveyance sensor for detecting the passage of the recording medium in the conveyance path inside the extended sheet feeding apparatus and determining the speed and timing of sending the recording medium to the image forming apparatus. 216 and 217 are solenoid drive means and a solenoid for picking up a recording medium in accordance with a paper feed timing instruction from the option CPU, and 218 is a paper size sensor for detecting the paper size of the recording medium stored in the paper feed cassette. It is. The paper size sensor 218 normally employs an nbit push button switch. When the threshold of the paper regulating plate mounted on the paper feed cassette is slid according to the paper size of the recording medium, any of the nbit push buttons is used. It is a mechanism for turning on / off.

  The option CPU 202 recognizes the paper size by detecting the switching of the nbit code corresponding to the paper size. 219 is motor drive means 2 for driving and controlling the motor of the recording medium storage unit of the extended sheet feeding device in accordance with an instruction from the option CPU, 220 is a lift-up that moves the recording medium storage unit of the expansion sheet feeding unit up to the sheet feeding start position It is a motor.

  Reference numeral 221 denotes a paper surface position detection sensor for detecting the paper surface position of the recording medium in the paper feed cassette, and 222 denotes a paper presence / absence detection sensor for detecting the presence or absence of the recording medium loaded on the paper feed cassette. When the paper surface of the recording medium does not reach the paper surface position detection sensor 221, the lift-up motor 220 lifts the storage container loaded with the recording medium (not shown).

  When the paper surface of the recording medium reaches the paper surface position detection sensor 221, the lift-up operation of the storage container by the lift-up motor 220 stops. The presence / absence of a recording medium is detected by the paper presence / absence detection sensor 222 in a state where the lift-up operation of the storage container is completed. The storage container has a hole where the sensor flag can be dropped at the position of the paper presence / absence detection sensor 222. When no recording medium is loaded on the storage container, the sensor flag falls into the hole of the storage container, indicating that there is no paper. To detect.

  As described above, the recording medium 207 stored in the paper feed cassette is driven up by the lift-up motor 220 to the paper feed start position. Then, driving is started at the speed setting instructed from the engine CPU via serial communication, and the timing of starting the paper feeding operation is notified to the option CPU 202 by inverting the level of the TMG 208 as the synchronization means. The option CPU 202 detects that the level of the TMG 208 is reversed and turns on the solenoid 217, whereby the recording medium 207 is fed.

<Operation of image forming system>
FIG. 2 is a timing chart showing the operation of the image forming system according to the first embodiment of the present invention. FIG. 3 is a flowchart for explaining the operation of the image forming system according to the first embodiment of the present invention. The operation of the image forming system according to the first embodiment of the present invention will be described with reference to FIGS. In FIG. 2, 1 indicates the communication start timing in the recording medium measurement mode, and 2 indicates the communication end timing in the recording medium measurement mode. Reference numeral 3 denotes a CLK 203 signal used for serial communication, which is transmitted from the engine CPU 62 and received by the option CPU 202. Reference numeral 4 denotes a CMD 204 signal used for serial communication, which is transmitted from the engine CPU 62 and received by the option CPU 202.

  The contents instructed to the option CPU 202 from the engine CPU 62 included in the CMD 4 include, for example, a rotation / stop instruction of the paper feed motor 210, a paper feed start instruction, a recording medium conveyance pause / restart instruction, and the like. In the embodiment of the present invention, the recording medium measurement mode instruction, the rotation speed instruction of the paper feed motor 210 in the recording medium measurement mode, and the like are also included in the CMD.

  Reference numeral 5 denotes a CMD interrupt signal branched from the CMD 204 and input to the interrupt port of the option CPU 202. Reference numeral 6 denotes an STS 206 signal used for serial communication. After the option CPU 202 confirms reception of the CMD from the engine CPU 62, it is transmitted from the option CPU 202 and received by the engine CPU 62. Reference numeral 8 denotes a TMG 208 signal for synchronizing the operation controlled by the engine CPU 62 and the operation controlled by the option CPU 202, which is transmitted from the engine CPU 62 and received by the option CPU 202.

  The engine CPU 62 holds the signal level of the CMD 204 at a high level before the start of communication, and sets it to a low level as the communication starts. The option CPU 202 determines that the CMD from the engine CPU 62 is transmitted at the timing when the level of the CMD 204 is reversed from High to Low (5-A period), and waits for receiving the CMD with the interrupt disabled. To. Then, the engine CPU 62 transmits CMD transmission CLK (3-A) and CMD (4-A) to the option CPU 202, and inverts the level of CMD4 from Low level to High level. The CMD4 holds the High level until the next communication is started. Next, the engine CPU 62 transmits the STS reception CLK (3-B) to the option CPU 202 to enter a standby state for receiving the STS.

  When the option CPU 202 receives the CMD (4-A), the option CPU 202 analyzes the content of the received CMD and transmits the STS (6-B) to the engine CPU 62. At this time, the option CPU 202 transmits STS (6-B) to the engine CPU 62 in synchronization with the STS reception CLK (3-B) transmitted from the engine CPU 62. When the option CPU 202 transmits the STS (6-B), the setting of the CMD interrupt signal 5 is inverted from the low level to the high level to make the interrupt enabled state (period 5-B), and enters the standby state for receiving the next CMD. To do.

  Thereafter, similarly, CMD (4 is synchronized with CLK (3-C, 3-E, 3-G, 3-I, 3-K, 3-M, 3-O, 3-Q) transmitted from the engine CPU 62. -C, 4-E, 4-G, 4-I, 4-K, 4-M, 4-O, 4-Q) are transmitted to the option CPU 202. The option CPU 202 synchronizes with the CLK (3-D, 3-F, 3-H, 3-J, 3-L, 3-N, 3-P, 3-R) transmitted by the engine CPU 62 and the STS (6- D, 6-F, 6-H, 6-J, 6-L, 6-N, 6-P, 6-R) are transmitted to the engine CPU 62. As for the CMD interrupt, the interrupt is disabled at the low level and the interrupt is enabled at the high level as described above.

  After the CMD4 is transmitted from the engine CPU 62 to the option CPU 202, retry communication is performed when the reception of the STS 6 from the option CPU 202 cannot be confirmed within a predetermined time. Retry communication is normally performed about 1 to 3 times, and if it still cannot receive STS6, it is considered as a communication error.

  Next, the operation in the recording medium measurement mode will be described. In FIG. 3, first, a recording medium is fed from the extended sheet feeder 200 (S101). Next, the recording medium is transported at a predetermined transport speed at which a normal printing operation is performed, and is transported to the transport sensor 114 in the image forming apparatus 100 via the transport sensor 214 in the extended sheet feeder 200 as described above. . When the conveyance sensor 114 is turned on (S102), the recording medium is temporarily stopped at the position of the registration roller 115 (S105). If the conveyance sensor 114 is not turned on even after a predetermined time has elapsed (S103), the process ends as a recording medium feed delay error (S104).

  In CMD4 described with reference to FIG. 2, first, the option CPU 202 is instructed to start the recording medium measurement mode by CMD (4-A). In CMD (4-C), the option CPU 202 is notified of the conveyance speed of the paper feed motor 210 in the recording medium measurement mode (S106).

  In the recording medium measurement mode, in order to perform measurement at a plurality of points on the recording medium, the recording medium is conveyed and paused at the measurement point, and the recording medium is conveyed and paused at the next measurement point. Therefore, the rotation speed of the paper feed motor 210 may instruct rotation of one to several clock pulses depending on the measurement point of the recording medium. In CMD (4-E), TMG8 reverses from Low level to High level, that is, sends an instruction to define the timing for starting the conveyance at the rising edge of TMG (8-A) (S107).

  In the next CMD (4-G), the TMG 8 reverses from the High level to the Low level, that is, sends an instruction for defining the timing for stopping the conveyance at the fall of the TMG (8-A) (S108). In the next CMD (4-I), the number of repetitions of starting / stopping of the paper feeding motor 210 by the repetition of the high / low level of the TMG 8 is instructed (S109).

  In this embodiment, eight measurement points of the recording medium are set, and the engine CPU 62 transmits TMG (8-A to 8-H) that only starts and stops the paper feed motor 210 eight times. The number of repetitions may be arbitrarily set according to the measurement environment of the recording medium. The operation of the TMG (8-A to 8-H) is also interlocked with the conveyance motor 120 on the image forming apparatus 100 side. By directly instructing the timing of the TMG (8-A to 8-H) from the engine CPU 62, the transport motor 120 and the paper feed motor 210 on the image forming apparatus 100 side are not affected by the delay time due to serial communication. Can be matched with high accuracy.

  When TMG (8-A to 8-H) is received by the option CPU 202, the paper feed motor 210 is started and stopped in synchronization with this (S110).

  The CMD (4-K to 4-O) during the period when the engine CPU 62 is measuring the recording medium by the media sensor 118 (the period of TMG (8-A to 8-H for the option CPU 202)) is used to measure the recording medium. Unrelated content can be communicated. The contents not related to the measurement include, for example, exchange of detection information by various sensors, monitoring of an error state of the extension sheet feeding device, and the like.

  When the engine CPU 62 finishes measuring the recording medium (S111), the CMD (4-Q) instructs the option CPU 202 to end the recording medium measuring mode. The option CPU 202 stops the paper feed motor 210 of the extended paper feeder and ends.

  As described above, in the recording medium measurement mode, the transfer speed and start / stop timing of the transfer unit on the image forming apparatus side and the transfer unit on the extended sheet feed unit side are not affected by the delay time due to the serial communication between both CPUs. The conveyance speed and start / stop timing can be controlled identically. As a result, the recording medium can be transported in a stable posture while avoiding pushing of the recording medium to the image forming apparatus side and pulling of the recording medium from the image forming apparatus side. Then, by conveying the recording medium in a stable posture, it is possible to improve the measurement accuracy of the recording medium type discrimination by the media sensor.

  In the embodiment of the present invention, it has been explained that the timing signal line is used in the recording medium measurement mode to synchronize the conveying means of the image forming apparatus and the extended sheet feeding apparatus. However, the operation of the recording medium other than the measurement mode can also synchronize the image forming apparatus and the conveying means of the extended sheet feeder.

<Configuration of image forming system>
FIG. 4 is a diagram for explaining the configuration of the image forming system according to the second embodiment of the present invention, in which the configuration in the case where three stages of extension paper feeding devices are mounted on the image forming device is described. In describing the configuration of the image forming system according to the present exemplary embodiment, the detailed description of the reference numerals described above is omitted. In FIG. 4, the extended sheet feeder closest to the image forming apparatus is referred to as an extended sheet feeder A, for example, an option CPU_A, a sheet feed motor A, or the like. Similarly, the second-stage expansion sheet feeding apparatus is the expansion sheet feeding apparatus B, and the third-stage expansion sheet feeding apparatus is the expansion sheet feeding apparatus C.

  The components mounted on the extended sheet feeder A perform the same functions as those described in the first embodiment. The paper size sensor 218, the lift-up motor driving means 219, the lift-up motor 220, the paper surface position detection sensor 221 and the paper presence / absence detection sensor 222 already described are omitted because they are the same as described above. The extended paper feeders B and C are also described with the above-mentioned functions, although they are mounted.

  Functions installed in the extended sheet feeding device B, the option controller 301, the option CPU 302, the motor driving unit 309, the sheet feeding motor 310, the transport sensor 314, the solenoid driving unit 316, and the solenoid 317 are functions corresponding to the expanded sheet feeding device A. It has the same function.

  Further, the option controller 401, the option CPU 402, the motor driving means 409, the paper feeding motor 410, the transport sensor 414, the solenoid driving means 416, and the solenoid 417 mounted on the extended paper feeding device C are those of the extended paper feeding devices A and B. With the same functions.

  Reference numeral 203 denotes a CLK. Reference numerals 203A, 203B, and 203C denote CLKs input to the option CPU_A, CPU_B, and CPU_C, respectively. These CLKs are input to the option CPUs at the same time.

  Reference numeral 204 denotes a CMD, 204A denotes a CMD signal line input to the option CPU_A, 204B denotes a CMD signal line input to the option CPU_B, and 204C denotes a CMD signal line input to the option CPU_C. 206 is an STS, and 206A, 206B, and 206C are STSs that are output from the options CPU_A, CPU_B, and CPU_C to the engine CPU 62, respectively.

  Here, CMD is sequentially input to each option CPU A, B, C. Each CMD is assigned an ID of an extended sheet feeder such as CMD4A, CMD4B, and CMD4C. The CMD is once input to the option CPU_A 202, and if the CMD is CMD4A, the option CPU_A 202 returns STS6A to the engine CPU 62. If the CMD is CMD4B or CMD4C, the option CPU_A 202 passes the CMD to the options CPU_B 302 and CPU_C 402 side.

  Similarly, CMD4B or CMD4C is once input to option CPU_B302, and if CMD is CMD4B, option CPU_B302 returns STS6B to engine CPU62. If the CMD is CMD4C, the option CPU_B 302 passes the CMD to the option CPU_C 402 side. The passed CMD4C is input to the option CPU_C402, and STS6C is returned to the engine CPU62.

  205A is an interrupt signal line from which the CMD 204 is branched inside the option controller 201, and is connected to the interrupt port of the option CPU_A. 205B is an interrupt signal line from which the CMD 204 is branched in the option controller 301, and is connected to the interrupt port of the option CPU_B. 205C is an interrupt signal line from which the CMD 204 is branched inside the option controller 401, and is connected to the interrupt port of the option CPU_C.

<Operation of image forming system>
FIG. 5 is a timing chart showing the operation of the image forming system according to the second embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation of the image forming system according to the second embodiment of the present invention. The operation of the image forming system according to the second embodiment of the present invention will be described with reference to FIGS. In the recording medium measurement mode described in this embodiment, the recording medium is fed and conveyed from the extended sheet feeding device C, and the recording medium is measured by the media sensor 118 installed in the image forming apparatus 100. And

  First, the ID of the extended sheet feeding device C that feeds the recording medium is designated (S201). In FIG. 5, the CMD (4C-A) is designated with the ID of the extended sheet feeder at the head (for example, 01, 02, 03 for the expanded sheet feeder A, the expanded sheet feeder B, and the expanded sheet feeder C, respectively). Is a command for instructing the option CPU to start the recording medium measurement mode. In the case of the present embodiment, an instruction is given to the option CPU_C 402 of the extended sheet feeding device C that feeds and conveys the recording medium to be in the recording medium measurement mode. On the other hand, the option CPU_C 402 transmits a status signal STS (6C-B) notifying the engine CPU 62 that CMD (4C-A) has been received.

  Next, the sheet feeding operation is started from the designated extended sheet feeding device C (S202). The recording medium is transported at a predetermined transport speed at which a normal printing operation is performed, and is sent to the extended paper feeder B via the transport sensor 414 in the extended paper feeder C. The extended sheet feeder B conveys the recording medium to the extended sheet feeder A via the conveyance sensor 314 in the extended sheet feeder B at a predetermined conveyance speed at which the printing operation is performed. The extended sheet feeder A conveys the recording medium to the image forming apparatus 100 via the conveyance sensor 214 in the extended sheet feeder A at a predetermined conveyance speed at which the printing operation is performed.

  When the recording medium reaches the conveyance sensor 114 in the image forming apparatus 100 and the conveyance sensor 114 is turned on (S203), the recording medium is temporarily stopped at the position of the registration roller 115 (S206). If the conveyance sensor 114 is not turned on after a predetermined time has elapsed (S204), the process ends as a recording medium feed delay error (S205).

  In step S207, the CMD (4A-C) specifies the ID of the extended sheet feeding apparatus A at the head of the command, and notifies the option CPU_A202 of the conveyance speed of the sheet feeding motor A210 in the recording medium measurement mode. On the other hand, the option CPU_A 202 transmits a status signal STS (6A-D) notifying the engine CPU 62 that CMD (4A-C) has been received.

  Subsequently, in CMD (4B-E), the ID of the extended sheet feeding device B is specified at the head of the command, and the conveying speed of the sheet feeding motor B310 in the recording medium measurement mode is notified to the option CPU_B302. On the other hand, the option CPU_B 302 transmits a status signal STS (6B-F) notifying the engine CPU 62 that CMD (4B-E) has been received. Similarly, in CMD (4C-G), the ID of the extended sheet feeding device C is specified at the beginning of the command, and the conveying speed of the sheet feeding motor C410 in the recording medium measurement mode is notified to the option CPU_C402. On the other hand, the option CPU_C 402 transmits a status signal STS (6C-H) notifying the engine CPU 62 that CMD (4C-G) has been received.

  As described above, when a multi-stage extended sheet feeder is installed, by assigning the ID of each extended sheet feeder, the extended sheet feeder of the stage assigned with each ID executes the instruction.

  Similarly, in S208, the CMD (4A-I) sends an instruction to the option CPU_A 202 to define the timing at which the TMG 8 is inverted from the Low level to the High level, that is, the transfer is started at the rising edge of the TMG (8-A). Then, the option CPU_A 202 transmits a status signal STS (6A-J) notifying the engine CPU 62 that CMD (4A-I) has been received. Subsequently, an instruction for defining the timing for starting the conveyance at the rising edge of TMG (8-A) is similarly sent to the option CPU_B 302 and the option CPU_C 402.

  Similarly, although not shown in FIG. 5, in S209, the TMG 8 reverses from the High level to the Low level, that is, sends an instruction for defining the timing for stopping the conveyance at the fall of the TMG (8-A) to each option CPU. In the next command, the number of repetitions of starting / stopping of the sheet feeding motor due to repetition of the high / low level of TMG 8 is instructed (S210).

  The TMG (8-A to 8-H) timing is instructed directly from the engine CPU to each of the option CPUs, so that the transfer motor on the image forming apparatus side is not affected by the delay time due to serial communication. The operation with the paper feed motor can be matched with high accuracy.

  When the TMGs (8-A to 8-H) are received by the option CPU_A 202, B302, C402, the paper feed motors A210, B310, C410 are started and stopped in synchronism with this (S211). The CMD (4-O to 4-W) during the period during which the engine CPU 62 is measuring the recording medium by the media sensor 118 (the TMG (8-A to 8-H) for the option CPU 202) is used to measure the recording medium. Unrelated content can be communicated.

  When the engine CPU 62 ends the measurement of the recording medium (S212), the CMD (4-Y) instructs the options CPU_A 202, B302, and C402 to end the recording medium measurement mode. The option CPU_A 202, B 302, C 402 stops the sheet feeding motors A 210, B 310, C 410 of the extension sheet feeding apparatuses A, B, C and ends.

  As described above, even when a plurality of extended sheet feeding apparatuses are connected to the image forming apparatus, the recording medium measurement mode is not affected by the delay time due to the serial communication between the engine CPU and the option CPU. As a result, the conveyance speed and start / stop timing of the conveyance means on the image forming apparatus side and the plurality of extended sheet feeding apparatus sides can be controlled in the same way. Then, the recording medium can be transported in a stable posture while avoiding pushing of the recording medium to the image forming apparatus side and pulling of the recording medium from the image forming apparatus side. That is, the measurement accuracy of the recording medium type discrimination by the media sensor can be improved by transporting the recording medium in a stable posture.

  In the embodiment of the present invention, it has been described that the timing signal line is used in the recording medium measurement mode to synchronize the image forming apparatus and the conveying means of the plurality of extended sheet feeding apparatuses. However, the operation of the recording medium other than the measurement mode can also synchronize the image forming apparatus and the conveying means of the extended sheet feeder.

  In the embodiment of the present invention, the synchronization of the image forming apparatus and the conveying means of the plurality of extended sheet feeding apparatuses has been described. However, it is also possible to control the conveying means of the plurality of extended sheet feeding apparatuses so as to synchronize only the part related to the conveyance of the recording paper.

<Configuration of image forming system>
FIG. 7 is a diagram for explaining the configuration of the image forming system according to the third embodiment of the present invention. In the case where the image forming apparatus is mounted with an expansion sheet feeding device having one option CPU 502 and three sheet feeding means. Describes the configuration. In describing the configuration of the image forming system according to the present exemplary embodiment, the detailed description of the reference numerals described above is omitted. In FIG. 7, a sheet feeding unit closest to the image forming apparatus is referred to as a sheet feeding unit A, which is referred to as a sheet feeding motor A, a motor driving unit A, or the like. Similarly, the second-stage paper feeding means is the paper feeding means B, and the third-stage paper feeding means is the paper feeding means C.

  Paper size sensor, lift-up motor driving means, lift-up motor, paper surface position detection sensor, and paper presence / absence detection sensor which are mounted on paper supply means A, paper supply means B, and paper supply means C and are controlled by the option CPU 502 Is the same as described above, and is omitted.

  Also, the motor drive means, the paper feed motor, the conveyance sensor, the solenoid drive means, and the solenoid that are components to be controlled by the option CPU 502 and are mounted on the paper feed means A, the paper feed means B, and the paper feed means C are described in the present invention. Since this is the same as the second embodiment, detailed description thereof is omitted.

  Reference numeral 203 denotes a CLK signal line, 204 denotes a CMD signal line, 206 denotes an STS signal line, and 205 denotes an interrupt signal line branched from the CMD 204 inside the option controller 501, which is connected to an interrupt port of the option CPU 502. .

<Operation of image forming system>
Since the timing chart showing the operation of the image forming system according to the third embodiment of the present invention and the flowchart explaining the operation are the same as those of the second embodiment of the present invention, FIG. 5 and FIG. The operation of the image forming system of the third embodiment will be described. In the recording medium measurement mode described in the present embodiment, the recording medium is fed and transported from the paper feeding unit C, and the recording medium is measured by the media sensor 118 installed in the image forming apparatus 100. To do.

  First, the engine CPU 62 designates the sheet feeding means C for feeding the recording medium to the option CPU 502 (S201). In FIG. 5, CMD (4C-A) designates the location of the paper feed means at the head of the command (for example, 01 for paper feed means A, 02 for paper feed means B, 03 for paper feed means C, etc. Is a command for instructing the option CPU to start the recording medium measurement mode. The option CPU 502 transmits a status signal STS (6C-B) notifying the engine CPU 62 that CMD (4C-A) has been received.

  Next, the paper feeding operation is started from the designated paper feeding means C (S202). The recording medium is transported at a predetermined transport speed at which a normal printing operation is performed, and is sent to the paper feeding unit B via the transport sensor 714 in the paper feeding unit C. The sheet feeding unit B conveys the recording medium to the sheet feeding unit A via the conveyance sensor 614 in the sheet feeding unit B at a predetermined conveyance speed at which the printing operation is performed. The sheet feeding unit A conveys the recording medium to the image forming apparatus 100 via the conveyance sensor 514 in the sheet feeding unit A at a predetermined conveyance speed at which the printing operation is performed.

  When the recording medium reaches the conveyance sensor 114 in the image forming apparatus 100 and the conveyance sensor 114 is turned on (S203), the recording medium is temporarily stopped at the position of the registration roller 115 (S206). If the conveyance sensor 114 is not turned on after a predetermined time has elapsed (S204), the process ends as a recording medium feed delay error (S205).

  In step S207, the CMD (4A-C) designates a code which is an instruction for the paper feeding unit A at the head of the command, and notifies the option CPU 502 of the conveyance speed of the paper feeding motor A510 in the recording medium measurement mode. . On the other hand, the option CPU 502 transmits a status signal STS (6A-D) notifying the engine CPU 62 that CMD (4A-C) has been received.

  Subsequently, in CMD (4B-E), a code which is an instruction for the paper feeding means B is designated at the head of the command, and the option CPU 502 is notified of the conveyance speed of the paper feeding motor B 610 in the recording medium measurement mode. On the other hand, the option CPU 502 transmits a status signal STS (6B-F) notifying the engine CPU 62 that CMD (4B-E) has been received. Similarly, in CMD (4C-G), a code that is an instruction to the paper feeding unit C is specified at the head of the command, and the option CPU 502 is notified of the conveyance speed of the paper feeding motor C710 in the recording medium measurement mode. On the other hand, the option CPU 502 transmits a status signal STS (6C-H) notifying the engine CPU 62 that CMD (4C-G) has been received.

  As described above, when the image forming apparatus 100 is mounted with an expansion sheet feeding device having one option CPU 502 and three sheet feeding units, each sheet feeding unit is designated in the CMD sent from the engine CPU 62 to the option CPU 502. assign. As a result, the sheet feeding means of each assigned stage executes the instruction.

  Similarly, in S208, in the CMD (4A-I), the TMG 8 is reversed from the Low level to the High level with respect to the option CPU 502, that is, the conveyance of the sheet feeding motor A 510 of the sheet feeding unit A is started at the rising edge of TMG (8-A). Send instructions to define when to do. Then, the option CPU 502 transmits a status signal STS (6A-J) notifying the engine CPU 62 that CMD (4A-I) has been received. Subsequently, an instruction for defining the timing for starting the feeding of the paper feeding motor B 610 and the paper feeding motor C 710 is sent to the paper feeding means B and C as well at the rising edge of TMG (8-A).

  Similarly, although not shown in FIG. 5, in S209, TMG 8 reverses from the High level to the Low level, that is, an instruction for defining the timing for stopping the conveyance of each stage of the paper feed motor at the fall of TMG (8-A). Is sent to the option CPU 502. In the next command, the number of repetitions of starting / stopping the paper feeding motor by repeating the high / low level of the TMG 8 is instructed (S210).

  The timing of this TMG (8-A to 8-H) is instructed directly from the engine CPU to the option CPU, so that it is not affected by the delay time due to serial communication. As a result, the operations of the conveyance motor 120 on the image forming apparatus 100 side and the sheet feeding motor A 510, the sheet feeding motor B 610, and the sheet feeding motor C 710 on the extended sheet feeding apparatus side can be matched with high accuracy.

  When TMG (8-A to 8-H) is received by the option CPU 502, the paper feed motors A510, B610, and C710 are started and stopped in synchronization with this (S211). The CMD (4-O to 4-W) during the period during which the engine CPU 62 is measuring the recording medium by the media sensor 118 (the TMG (8-A to 8-H) for the option CPU 502) is used to measure the recording medium. Unrelated content can be communicated.

  When the engine CPU 62 ends the recording medium measurement (S212), the CMD (4-Y) instructs the option CPU 502 to end the recording medium measurement mode. The option CPU 502 stops the paper feeding motors A510, B610, and C710 of the paper feeding means A, B, and C and ends the processing.

  As described above, even when an extended sheet feeder having at least one sheet feeder is connected to the image forming apparatus, the delay due to the serial communication between the engine CPU and the option CPU in the recording medium measurement mode. Not affected by time. Therefore, the conveyance speed and start / stop timing of the conveyance unit on the image forming apparatus side and the conveyance speed and activation / stop timing of at least one conveyance unit on the extended sheet feeding apparatus side can be controlled to be the same. As a result, the recording medium can be transported in a stable posture while avoiding pushing of the recording medium to the image forming apparatus side and pulling of the recording medium from the image forming apparatus side. Then, by conveying the recording medium in a stable posture, it is possible to improve the measurement accuracy of the recording medium type discrimination by the media sensor.

  In the embodiment of the present invention, it has been described that the timing signal line is used in the recording medium measurement mode to synchronize at least one conveyance unit of the image forming apparatus and the extended sheet feeding apparatus. However, it is possible to synchronize the image forming apparatus and the conveying means of at least one extended sheet feeding apparatus for operations other than the measurement mode of the recording medium.

  In the embodiment of the present invention, the configuration of the extended sheet feeding device is one option CPU and three stages of sheet feeding means. However, the present invention is not limited to this configuration, and an equivalent function can be satisfied even in an arbitrary combination of configurations.

  Further, in the embodiment of the present invention, the synchronization of at least one conveyance unit of the image forming apparatus and the extended sheet feeding apparatus has been described. However, it is also possible to perform control so that only the part related to the conveyance of the recording paper is synchronized with respect to at least one conveyance unit of the extended sheet feeding device.

1 is a block diagram illustrating the configuration of an image forming system according to a first embodiment. Timing chart for explaining the operation of the image forming system of the first embodiment Flowchart for explaining the operation of the image forming system of the first embodiment. Block diagram illustrating the configuration of an image forming system according to a second embodiment Timing chart for explaining the operation of the image forming system of the second embodiment Flowchart for explaining the operation of the image forming system of the second embodiment. Block diagram for explaining the configuration of the image forming system of the third embodiment 1 is a diagram illustrating a schematic configuration of a conventional image forming apparatus and an extended sheet feeding apparatus. FIG. 2 is a diagram illustrating a configuration of a serial interface between a conventional image forming apparatus and an extended sheet feeding apparatus. Diagram showing an example of the configuration of the media sensor Example of digital processing of surface image of recording medium and output data of image sensor Control system block diagram for performing control based on detection data from media sensor

Explanation of symbols

3 CLK signal 4 CMD signal 5 CMD interrupt signal 6 STS signal 8 TMG signal 61 Engine controller 62 Engine CPU (corresponding to the first control means)
66 Motor drive means (corresponding to the first transport means)
DESCRIPTION OF SYMBOLS 100 Image forming apparatus 107,207 Recording medium 114 Conveyance sensor 118 Media sensor (Recording medium discrimination means)
120 motor (corresponding to the first conveying means)
200 Extended paper feeder 201, 301, 401, 501 Option controller 202, 302, 402, 502 Option CPU (corresponding to second control means)
203 CLK signal line (corresponding to serial communication means)
204 CMD signal line (corresponding to serial communication means)
205 CMD interrupt signal line (corresponding to serial communication means)
206 STS signal line (corresponding to serial communication means)
208 TMG signal line (corresponding to synchronization means)
209, 309, 409, 509, 609, 709 Motor drive means (corresponding to the second transport means)
210, 310, 410, 510, 610, 710 Paper feed motor (corresponding to the second conveying means)
214, 314, 414, 514, 614, 714 Conveyance sensors 216, 316, 416, 516, 616, 716 Solenoid driving means 217, 317, 417, 517, 617, 717 Solenoid

Claims (15)

In an image forming system comprising an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and an expansion sheet feeding apparatus that can be expanded and connected to the image forming apparatus.
A first control unit that controls the image forming apparatus; a second control unit that controls the extended sheet feeding device;
A first conveying unit installed in the image forming apparatus for conveying a recording medium; a second conveying unit installed in the extended sheet feeding apparatus for conveying a recording medium;
Serial communication means for performing communication and control between the first control means and the second control means;
Synchronization means for matching the operation timing of the first transport means and the operation timing of the second transport means;
A recording medium determining means for determining the type of the recording medium;
In the recording medium measurement mode of the recording medium determination unit, when the recording medium is fed and conveyed from the extended sheet feeding device to the image forming apparatus, the operation timing of the first conveying unit and the first timing are adjusted by the synchronization unit. An image forming system characterized in that it synchronizes with the operation timing of the two conveying means.   In the recording medium measurement mode, the definition of the operation performed by the second control unit with respect to the synchronization unit is defined in advance from the first control unit to the second control unit using the serial communication unit. The image forming system according to claim 1, wherein notification is performed.   The definition related to the operation instructed by the synchronization means is the setting of the speed of the second transport means, the start of transport of the recording medium, the waiting for transport of the recording medium, and the number of times of measurement of the recording medium. The image forming system according to claim 2.   2. The start and stop timings of the second transport unit are notified from the first control unit to the second control unit by the synchronization unit in the recording medium measurement mode. 3. The image forming system according to any one of 3 above.   5. The image according to claim 1, wherein the synchronization means is a timing signal line electrically connected to general-purpose input / output terminals of the first control means and the second control means. Forming system. In an image forming system including an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and a plurality of expansion paper feeding apparatuses that can be expanded and connected to the image forming apparatus.
A first control unit that controls operations of the image forming apparatus; a plurality of control units that control operations of the plurality of extended sheet feeding devices;
A first conveying unit that is installed in the image forming apparatus and conveys a recording medium; and a plurality of conveying units that are respectively installed in the plurality of extension paper feeding devices and convey the recording medium;
Serial communication means for sequentially communicating and controlling between the image forming apparatus and the plurality of extended sheet feeding apparatuses;
Synchronization means for matching the operation timing of the first conveying means and the operation timing of the plurality of conveying means;
A recording medium determining means for determining the type of the recording medium;
In the recording medium measurement mode of the recording medium determination unit, when the recording medium is fed and conveyed from any one of the plurality of extended sheet feeding apparatuses to the image forming apparatus, the first conveyance is performed by the synchronization unit. An image forming system characterized in that the operation timing of the means is synchronized with the operation timing of the plurality of conveying means.   In the recording medium measurement mode, the definition of the operation performed by the plurality of control units that control the plurality of expansion sheet feeding devices with respect to the synchronization unit is defined from the first control unit to the plurality of units using the serial communication unit. 7. The image forming system according to claim 6, wherein notification is made in advance to a plurality of control means for controlling the extended sheet feeding apparatus.   The definition related to the operation instructed by the synchronization means is the setting of the speed of the plurality of transport means, the start of transport of the recording medium, the waiting for transport of the recording medium, and the number of times of measurement of the recording medium. The image forming system according to claim 7.   In the recording medium measurement mode, the synchronization unit notifies the start and stop timings of the plurality of transport units from the first control unit to a plurality of control units that control the operations of the plurality of extended sheet feeding apparatuses. The image forming system according to claim 6, wherein the image forming system is an image forming system.   The synchronizing means is a timing signal line electrically connected to general-purpose input / output terminals of a plurality of control means for controlling operations of the first control means and the plurality of extended sheet feeding apparatuses. The image forming system according to claim 6. In an image forming system comprising an image forming apparatus that forms a toner image on a recording medium using an electrophotographic process, and an expansion sheet feeding apparatus that can be expanded and connected to the image forming apparatus.
First control means for controlling the operation of the image forming apparatus, at least one control means for controlling the operation of the extended sheet feeding apparatus,
A first conveying unit that is installed in the image forming apparatus and conveys a recording medium; and at least one or more conveying unit that is installed in the extended sheet feeding apparatus and conveys the recording medium;
Serial communication means for performing communication and control between the image forming apparatus and the extended sheet feeding apparatus;
Synchronization means for matching the operation timing of the first transport means with the operation timing of the at least one transport means;
A recording medium determining means for determining the type of the recording medium;
In the recording medium measurement mode of the recording medium determination unit, when the recording medium is fed and conveyed from any one of the conveying units in the extended sheet feeding device to the image forming apparatus, the synchronization unit performs the first An image forming system characterized in that an operation timing of a conveying unit and an operation timing of at least one conveying unit of the extended sheet feeder are synchronized.   In the recording medium measurement mode, the definition of the operation performed by at least one control unit that controls the expansion sheet feeding device with respect to the synchronization unit is defined from the first control unit using the serial communication unit. 12. The image forming system according to claim 11, wherein at least one control means is notified in advance.   The definition related to the operation instructed by the synchronization means is the setting of the speed of the at least one conveyance means, the start of conveyance of the recording medium, the waiting for conveyance of the recording medium, and the number of times of measurement of the recording medium. The image forming system according to claim 12.   In the recording medium measurement mode, the synchronization means starts and stops the at least one transport means, and at least one control means controls the operation of the extended sheet feeder from the first control means. The image forming system according to claim 11, wherein the image forming system is notified.   The synchronization means is a timing signal line electrically connected to a general-purpose input / output terminal of at least one control means for controlling the operation of the extended sheet feeder from the first control means. The image forming system according to claim 11.

Images