JP4954751B2 - Printing device - Google Patents

Description

  The present invention relates to a printing apparatus.

  A tandem type printing apparatus has a plurality of OPC (Organic Photo Conductor) drums corresponding to each color arranged side by side, forms a single color toner image on each drum, and transfers these single color toner images to an intermediate transfer belt. To a printing apparatus for secondary transfer onto a sheet. The tandem type printing apparatus has an advantage that the image forming time is shortened because the toner images of the respective colors are simultaneously formed using a plurality of OPC drums corresponding to the respective colors.

  By the way, in a printing apparatus typified by a printer apparatus, a copier apparatus, a facsimile apparatus, etc. that have already been widely used, there are those in which a main body apparatus and a plurality of option apparatuses (for example, an option feeder and a finisher) are connected by a bus. . When such an optional device is mounted on the main device, the control unit of the main device and the control unit of the optional device are connected, and data communication is performed between the main device and the optional device. As a communication method between the main unit and the optional device, a plurality of select lines are connected to the optional device by bus, the main unit switches the select line as appropriate, selects the optional device, and performs serial communication with the optional device. To do is generally done.

On the other hand, from the viewpoint of improving communication efficiency, a method of performing broadcast communication in which communication is performed simultaneously with all option devices has been proposed.
JP 2004-144919 A

  However, in the case of broadcast communication in which communication is performed simultaneously with all option devices, the selected option device is not uniquely determined, and each option device that returns a response returns a response. Therefore, a signal may collide with a communication line on the same bus, and a response may not be returned to the main unit, making it difficult to check the communication state of each option device.

  In view of the above-described problems, an object of the present invention is to enable reliable confirmation of the communication state of each option device when performing broadcast communication from a main device to a plurality of option devices.

  In order to solve the above-described problems, a printing apparatus according to the present invention is a printing apparatus in which a main apparatus and a plurality of option apparatuses are connected by a bus, and the main apparatus is broadcast to the plurality of option apparatuses. When communication is performed, only the option device having the lowest error rate among the plurality of option devices returns a response to the broadcast communication to the main body device.

  The printing apparatus according to the present invention employs a configuration in which the option device located farthest on the bus connection from the main body device is determined as the option device with the lowest error rate.

  In the printing apparatus of the present invention, before performing the broadcast communication, the main unit transmits a signal indicating an order corresponding to the distance on the bus connection as viewed from the main unit to the optional device. Adopting a configuration to do.

  In the printing apparatus of the present invention, the error rate between the main device and the plurality of optional devices is measured before the broadcast communication, and the highest error rate is determined according to the measurement result. A configuration is adopted in which a bad optional device is determined.

According to the printing apparatus of the present invention, when performing broadcast communication, all the optional devices receive this broadcast command, but only the optional device with the worst error rate among the optional devices, Returns a response to the server. Since the response is returned from the option device having the worst error rate, it can be confirmed that the broadcast command can be transmitted to all the option devices. Since a response is returned from the option device having the worst error rate, it is possible to prevent a signal from colliding with a communication line on the same bus.
Therefore, according to the printing apparatus of the present invention, it is possible to reliably check the communication state of each option device when performing broadcast communication from the main device to a plurality of option devices.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is applied to a printing apparatus represented by a printer apparatus, a copier apparatus, a facsimile apparatus, and the like. Here, a printer apparatus will be described as an example.

  FIG. 1 shows a configuration of a printer apparatus 1 according to the present embodiment. In FIG. 1, 11 is a printing apparatus main body (main body apparatus), and 12a to 12d are optional feeders (optional apparatus).

  The printing apparatus body 11 receives an image signal from an external personal computer or the like, and forms a color image from the image signal. The printing apparatus main body 11 includes an image processing unit 21, an image forming unit 22, a control unit 23, a paper tray 24, and a paper feed conveyance mechanism including a plurality of rollers and sensors. As the paper feed / conveying mechanism, there are a pickup roller 25 for taking out the paper stored in the paper tray 24, a retard roller 26 for separating and sending out one or more of the paper taken out by the pickup roller 25, It includes various rollers such as a conveyance roller 27 that conveys paper within the apparatus and a registration roller 28 that performs alignment correction, and a sensor for detecting the rotation of each roller and the paper being conveyed. These rollers are driven based on the control of the control unit 23. In addition, detection outputs of various sensors are supplied to the control unit 23. The control unit 23 is connected to an input unit 31 for performing input from various operation keys, a display unit 32 for displaying various states, and a storage unit 33 for storing various programs.

  The option feeders 12 a to 12 d are paper feeders of a type in which a plurality of feeders are stacked in multiple stages in the vertical direction, and are detachable from the printing apparatus main body 11. Here, four option feeders 12a to 12d are shown, but the number of option feeders is not limited to this.

  Each of the option feeders 12a to 12d has a control unit 51, a paper tray 52, and a paper feeding / conveying mechanism including a plurality of rollers and sensors. The paper feed and transport mechanism includes various rollers such as a pickup roller 53, a retard roller 54, and a transport roller 55, and sensors for detecting rotation of each roller and transported paper. These rollers are driven based on the control of the control unit 51. Further, the detection output of each sensor is sent to the control unit 51.

  The control unit 23 of the printing apparatus main body 11 is provided with a communication interface 34. The control interface 51 of the option feeders 12a to 12d is provided with a communication interface 59. When the option feeders 12a to 12d are attached to the printing apparatus main body 11, the communication interface 34 and the communication interface 59 are connected via the bus 60, and the control unit 23 of the printing apparatus main body 11 and the control units of the option feeders 12a to 12d are connected. Data communication with 51 is performed. That is, the printing apparatus main body 11 and the option feeders 12 a to 12 d are connected by bus via the communication interfaces 34 and 59 and the bus 60.

  When printing is performed by the printer device 1 of the present embodiment, an image signal from an external device is input to the interface 35. This image signal is sent to the image processing unit 21 via the control unit 23. The image processing unit 21 forms Y (yellow), C (cyan), M (magenta), and B (black) color signals from the input image signal. Each color signal is supplied to the exposure devices 36a, 36b, 36c, and 36d of the image forming unit 22, respectively.

  The image forming unit 22 is a tandem type image forming unit, and includes four OPC drums 37a, 37b, 37c, and 37d corresponding to colors of Y (yellow), M (magenta), C (cyan), and B (black). , Exposure devices 36a, 36b, 36c, 36d, an intermediate transfer belt 38, drive rollers 39a, 39b around which the intermediate transfer belt 38 is wound, and a fixing roller 40.

  When an image is formed by the image forming unit 22, first, the surfaces of the OPC drums 37a, 37b, 37c, and 37d are uniformly charged. The OPC drums 37a, 37b, 37c, and 37d are scanned and irradiated with laser light by the exposure devices 36a, 36b, 36c, and 36d based on the image signals of the respective colors. When the laser beam is irradiated, the electric charge in the portion irradiated with the laser beam is lost, and latent images are formed on the OPC drums 37a, 37b, 37c, and 37d. Then, the toner of each color is developed on the OPC drums 37a, 37b, 37c, and 37d of each color, and a toner image of each color is formed. This toner image is primarily transferred to the intermediate transfer belt 38.

  On the other hand, among the paper stored in the paper tray 24 of the printing apparatus main body 11 or the paper stored in the paper tray 52 of the option feeders 12a to 12d, the paper in the selected tray is fed as described above. The mechanism is transported to the secondary transfer position of the image forming unit 22 (for example, the position of the registration roller 28). The toner image transferred to the intermediate transfer belt 38 is secondarily transferred onto the fed paper. The toner image transferred onto the paper is fixed by the fixing roller 40 and discharged.

  FIG. 2 is a sequence diagram in the case where communication is performed between the control unit 23 of the printing apparatus main body 11 and the control unit 51 of the option feeders 12a to 12d in the present embodiment.

  Communication from the control unit 23 of the printing apparatus main body 11 includes select communication performed by selecting the option feeders 12a to 12d of the other party to perform communication, and broadcast communication that transmits all the option feeders 12a to 12d all at once. is there.

  In the select communication, the control unit 23 of the printing apparatus main body 11 selects the select line, switches to the option feeders 12a to 12d, sends a command to the control unit 51 of the selected option feeders 12a to 12d, and the control unit 51 When a command is received, a response is returned to the control unit 23 of the printing apparatus main body 11.

  That is, in FIG. 2, when selecting the option feeder 12a and performing the select communication, the control unit 23 of the printing apparatus main body 11 selects the select line for the option feeder 12a (step S1), and the option feeder 12a A command is transmitted to the control unit 51 (step S2). When receiving the command (step S3), the control unit 51 of the option feeder 12a returns a response to the control unit 23 of the printing apparatus main body 11 (step S4).

  When the option feeder 12b is selected and the select communication is performed, the control unit 23 of the printing apparatus main body 11 selects the select line for the option feeder 12b (step S5), and the control unit 51 of the option feeder 12b A command is transmitted (step S6). When receiving the command (step S7), the control unit 51 of the option feeder 12a returns a response to the control unit 23 of the printing apparatus main body 11 (step S8).

  On the other hand, when performing broadcast communication, the control unit 23 of the printing apparatus main body 11 selects all option feeders 12a to 12d with the select line as a specific pattern, and selects all option feeders 12a to 12d. A command is simultaneously sent to the control unit 51. The control units 51 of all the option feeders 12a to 12d receive this broadcast command, and only the control unit of the option feeder having the worst error rate among the option feeders 12a to 12d controls the printing apparatus main body 11. A response is returned to the unit 23.

  That is, in FIG. 2, it is assumed that the option feeder 12d is the option feeder with the lowest error rate. In FIG. 2, when performing broadcast communication, the control unit 23 of the printing apparatus main body 11 selects all option feeders 12a to 12d with the select line as a specific pattern (step S9), and all option feeders. A broadcast command is transmitted to the control units 51 of 12a to 12d (step S10). The control units 51 of all option feeders 12a to 12d receive the broadcast command and monitor the broadcast communication (steps S11a to 11d). Only the control unit 51 of the option feeder 12d having the worst error rate returns a response to the control unit 23 of the printing apparatus main body 11 (step S12).

  As described above, in the present embodiment, when performing broadcast communication, the control units 51 of all the option feeders 12a to 12d receive the broadcast command, but the error rate is set among the option feeders 12a to 12d. Only the control unit 51 of the worst option feeder 12d returns a response to the control unit 23 of the printing apparatus main body 11. For this reason, collision of response signals does not occur. In addition, the control unit 23 of the printing apparatus main body 11 has received a response from the control unit 51 of the option feeder 12d having the lowest error rate, so that the broadcast command has been transmitted to all the option feeders 12a to 12d. Can be confirmed.

  Here, among the option feeders 12a to 12d, the option feeder having the worst error rate is generally an option feeder that is farthest from the printing apparatus main body 11 on the bus connection. That is, in FIG. 1, the control unit 23 of the printing apparatus main body 11 and the control unit 51 of the option feeders 12 a to 12 d are connected via a bus 60. Since external noise is considered to enter through the bus 60, the option feeder 12d located farthest from the printing apparatus main body 11 on the bus connection is considered to have the worst error rate.

  Therefore, when the option feeder with the worst error rate is uniquely determined with the option feeder 12d physically located farthest from the printing apparatus main body 11, when performing broadcast communication, the option feeders 12a to 12d are Thus, only the control unit 51 of the option feeder 12d that is farthest from the printing apparatus main body 11 on the bus connection may return a response to the control unit 23 of the printing apparatus main body 11.

  That is, as shown in FIG. 3, in the initialization process, device numbers indicating the order of physical distances as viewed from the printing apparatus main body 11 are assigned to the option feeders 12a to 12d (step S51). It transmits to option feeder 12a-12d (step S52). Then, among the option feeders 12a to 12d, the option feeder that is physically farthest away from the printing apparatus body 11 is determined (step S53), and the option feeder that is physically farthest away from the printing apparatus body 11 is determined. Is given a response right in the case of broadcast communication (step S54).

  In the initialization process, a number may be assigned to each option device, an error rate may be measured with each option device, and an option device that returns a response may be determined. FIG. 4 is a flowchart showing the processing in that case.

  In FIG. 4, the control unit 23 of the printing apparatus main body 11 assigns a device number to each of the option feeders 12a to 12d in the initialization process (step S101). The device number is transmitted as a signal indicating the order to each option feeder 12a to 12d at the time of initialization (step S102). Then, the device number N is set to (N = 0) (step S103), and a test signal is transmitted to the option feeder of the device number N (N = 0) (step S104).

  When the control unit 51 of the option feeder with the device number N (N = 0) receives the test signal, it returns a response signal.

  When the control unit 23 of the printing apparatus main body 11 receives the response signal from the control unit 51 of the option feeder having the device number N (N = 0) (step S105), the error rate is detected based on the response signal (step S105). Step S106). Then, it is determined whether or not communication with all option feeders has been completed (step S107). If communication with all option feeders has not been completed, the device number N is incremented (step S108), and the process proceeds to step S104. Return.

  The above processing is repeated, and the error rate is detected in step S106 for all option feeders. If it is determined in step S107 that communication with all option feeders has been completed, the option feeder with the worst error rate is determined (step S109), and the option feeder with the worst error rate is broadcasted. Is given a response right (step S110).

  The embodiment of the present invention has been described above. However, the printing apparatus of the present invention is not limited to the illustrated example described above, and various modifications can be made without departing from the scope of the present invention. It is.

1 is a block diagram illustrating a configuration of a printing apparatus according to an embodiment of the present invention. It is a sequence diagram used for description of the printing apparatus which is one embodiment of the present invention. 3 is a flowchart used to describe a printing apparatus according to an embodiment of the present invention. 3 is a flowchart used to describe a printing apparatus according to an embodiment of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer apparatus, 11 ... Printing apparatus main body, 12a-12d ... Option feeder, 21 ... Image processing part, 22 ... Image forming part, 23 ... Control part, 24 ... Paper tray, 25 ... Pickup roller, 26 ... retard roller, 27 ... conveying roller, 28 ... registration roller, 31 ... input unit, 32 ... display unit, 34 ... communication interface, 35 ... interface, 36a to 36d ... exposure Device: 38 ... Intermediate transfer belt, 40 ... Fixing roller, 51 ... Control section, 52 ... Paper tray, 53 ... Pickup roller, 54 ... Retarding roller, 55 ... Conveying roller, 59 ... Communication interface 60 …… Bus

Claims (4)

A printing device in which a main device and a plurality of optional devices are connected by bus,
The main unit gives a response right in the case of broadcast communication to an option device having the worst error rate among the plurality of option devices,
When the main device performs broadcast communication with the plurality of option devices, only the option device with the lowest error rate among the plurality of option devices returns a response to the broadcast communication to the main device. A printing apparatus characterized by that.   The printing apparatus according to claim 1, wherein an option device located farthest on the bus connection from the main device is determined as the option device having the worst error rate.   3. The device according to claim 2, wherein before performing the broadcast communication, the main body device transmits a signal indicating an order corresponding to a distance on the bus connection as viewed from the main body device to the optional device. Printing device.   Before performing the broadcast communication, an error rate between the main device and the plurality of option devices is measured, and the option device having the worst error rate is determined according to the measurement result. The printing apparatus according to claim 1.

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