Canon Information Systems, Inc.

Toshiba Tech Corporation

Canon Kabushiki Kaisha

Daniel A Danknick

William C Russell

Robert D Wadsworth

Lorraine F Barrett

Tony K Ip

The disclosure relates to methods and apparatus for allocating a print job among multiple printers. The apparatus includes one or more computer workstations that are communicatively coupled to a controller. The controller is communicatively coupled to plural multifunction peripherals (MFPs) for printing. The system provides a user an option of designating a print job as a tandem mode job, wherein a controller utilizes the multiple MFPs in printing the job in order to decrease the overall print time. In one embodiment, the controller utilizes only two MFPs. In another embodiment, more than two MFPs are utilized. Regardless of the number of MFPs utilized, all of the MFPs are desirably controlled by the same controller.

Dynamic load balancing for a tandem printing system

The disclosure relates to methods and apparatus for handling error occurrences in an image outputting system. The system comprises plural multifunction peripherals (MFPs) for printing a document. Each MFP is communicatively coupled to a single control unit, the control unit being communicatively coupled to a computer workstation on a computer network. The control unit receives a print job from the computer workstation and then sends the print job to one or more hard output units. The control unit monitors the status of the print job with respect to each MFP to determine whether an error is present in any of the MFPs. If the control unit detects an error, it waits a predetermined time period to provide a user time to fix the error. If the user does not fix the error within the predetermined time period, the control unit then polls the status of the remaining MFPs to determine whether any other MFPs are error-free. The control unit then sends the print job to one or more of the error-free MFPs. If the print job includes multiple copies of a single document, the control unit desirably divides the copies between several MFPs in order to minimize the overall print time.

Error management for a tandem printing system

A network device which interfaces between a local area network (LAN) and an image forming apparatus and which can output debug information. The network device includes a LAN interface for receiving image forming jobs and command signals from the LAN and a peripheral interface for outputting image forming jobs to the image forming apparatus. The network device further includes a storage device that stores debug information regarding the network device configuration for receiving image forming jobs from the LAN and outputting image forming jobs to the image forming apparatus. In addition, the network device has a processor that detects a triggering condition and, in response to the triggering condition, formats the debug information into an image forming job and outputs the formatted debug information to the image forming apparatus.

Interface device connected between a LAN and a printer for outputting

An interactive network device which interfaces a LAN to a peripheral that includes a front panel through which a user can affect status changes to the peripheral. Included in the interactive network device are a LAN interface which interfaces to the LAN and over which peripheral data is communicated, and a peripheral interface which interfaces to the peripheral and over which the peripheral data is communicated and the status of the peripheral data is received. A processor analyzes the status of the peripheral received over the peripheral interface so as to detect a predetermined sequence of status changes in the peripheral and, in response to detection of the predetermined sequence of status changes, (a) generates testpage information containing at least one of network information and interactive network device information and (b) outputs the generated testpage information.

Network board which responds to status changes of an installed

A fail-safe flash for an EPROM that is arranged into separately erasable sectors proceeds in a stepwise procedure. The EPROM is divided into at least three regions including a boot block region, a file region and a directory region. The boot block region stores at least two independently erasable boot blocks, only one of which is designated as a current boot block, which performs scanning of the directory region so as to determine a current directory in the directory region. The file region stores all executables, including executables designated as critical and non-critical. The directory region stores multiple directories, only one of which is a current directory, which designates which is the current boot block, which of the files stored in the file region are available for loading for execution, as well as which of the files are critical and which are non-critical. In the first step to flash the EPROM, the unused region of the boot block is updated with the new boot block. In the second step of flashing the EPROM, critical files are flashed over non-critical files, and after correct installation of the newly-flashed critical files is confirmed, a new directory is written into the directory region referring only to the newly-flashed critical files. In the third step of flashing the EPROM, non-critical files are flashed, whereafter a new directory is written to the directory region referring to the newly-flashed critical files as well as to the newly-flashed non-critical files.

Fail-safe flashing of EPROM

A method of determining which of plural protocols are active on a computerized local area network. Each of plural frame types are registered with a link support layer (LSL) which monitors network communications for broadcast frame packets. A frame packet which matches a first one of the frame types is provided from LSL, and protocol header information in the received frame packet is decoded so as to determine protocol used in the frame packet. The first frame type is de-registered from LSL, a first protocol stack corresponding to the determined protocol is initialized using the first frame type, the first protocol stack is loaded, and the first protocol stack registers itself with LSL so that the first protocol stack receives future frame packets which match the first frame type. Thereafter, if LSL encounters any other frame types, the above processing is repeated so as to load and register any other needed protocol stacks.

Network protocol sensor

A serial port which transmits a start bit of a serial transmission to a non-maskable interrupt terminal of a microprocessor so as to be certain that the microprocessor responds to serial communication. The serial port includes a microprocessor-writable transmit bit connected to the transmit terminal of the serial port, a microprocessor-readable receive bit connected to the receive terminal of the serial port, and an NMI enable switch connected between the receive terminal and the NMI pin of the microprocessor. In a receive mode, the NMI enable switch which initially is in a conductive state, transmits the start bit of serial transmissions directly to the NMI pin of the microprocessor causing the microprocessor to interrupt on-going processes. The microprocessor disables the NMI enable register and, after waiting for serial transmission periods between transmitted bits, reads all eight data bits received at the receive terminal from the received bit. Thereafter, the microprocessor re-enables the NMI enable switch and resumes the suspended on-going processes. In a transmit mode, the microprocessor writes a binary 1, corresponding to a start bit, to the transmit bit, causing a transmit signal to be output from the transmit terminal. The microprocessor then transmits the eight bits corresponding to the desired transmit byte, each bit being separated by the appropriate inter-bit serial communication time interval.

Serial port using non-maskable interrupt terminal of a microprocessor

A data transfer method in which a sending processor sends data to a receiving processor via a shared memory using a put pointer and a get pointer, the values of pointers indicate a next location in the shared memory to be written and to be read. The sending processor executes a data-sending process by (1) by referring to a counter of outstanding acknowledgements to determine if there is available space, (2) if there is available space, reading the get and put pointers and determining whether the put pointer is equal to one of plural partition indices which correspond to a number of partitions into which the shared memory is divided, (3) in the case where the value of the put pointer is equal to one of the plural predetermined partition indices, writing a command requesting the receiving processor to issue an acknowledgement and updating the counter of outstanding acknowledgements by adding one, (4) writing a block of data at a location of the put pointer, and (5) updating of the put pointer. The data-sending process is suspended when the counter of outstanding acknowledgements indicates that there is insufficient space in shared memory. An acknowledgement is received from the receiving processor and the counter of outstanding acknowledgements is updated by reducing it by one. The data-sending process is re-executed after the receiving processor issues the acknowledgement.

Growing community of inventors

Orange, CA, United States of America

Daniel A Danknick