JP2005149030A - Printing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make it possible to start printing without waiting for the storage of a printing image for one page or the like or an intermediate code and to realize high throughput in printing operation. <P>SOLUTION: In the printing system including a controller for controlling the printing operation, a printing engine for executing printing on the basis of an image signal and a hardware unit for transmitting the image signal to the printing engine under the control of the controller, the hardware unit is provided with a processing module for generating the image signal and constituted so as to generate and transmit the image signal in accordance with a synchronizing signal sent from the printing engine. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming technique, and more particularly to a print system including a host device and a printer device.

  2. Description of the Related Art Conventionally, in a printing system including a host device and a printer device, 1) image processing (resolution conversion processing, halftone processing, color conversion processing, etc.) is performed by software on the host device to generate a print image, and 2) the host device The print image is transmitted from the printer to the printer device, 3) in the printer device, the controller transfers the print image to the print engine according to the synchronization signal of the print engine, and 4) the print engine executes printing. There are many cases.

  Under the framework as described above, since image processing has a large amount of data to be processed in the first place, the processing load is large, and it is not always possible to occupy the CPU resources of the host device for image processing. It has been difficult to generate a print image by executing image processing in real time according to the synchronization signal of the print engine (that is, in time for the transfer timing to the print engine).

  Therefore, conventionally, after generation and transmission of a print image is started in the host device, the printer device waits until a print image for one page, for example, is accumulated, and then the controller stores the print image according to the synchronization signal of the print engine. A configuration is employed in which the printed image is transmitted to the print engine.

  However, with such a configuration, it takes a certain time from the start of print image generation to the actual start of printing, resulting in a problem that sufficient throughput cannot be obtained.

  Such a problem occurs when a print job described in PDL (page description language) is transmitted from the host device to the printer device, and a print image is generated based on the print job in the printer device (or once expanded into an intermediate code). But it happens in the same way.

  Therefore, an object of the present invention is to provide a printing system that can start printing without waiting for accumulation of a print image or intermediate code for one page, for example, and can realize high throughput.

  The print system of the present invention includes a controller that controls a printing operation, a print engine that executes printing based on an image signal, a hardware unit that transmits an image signal to the print engine under the control of the controller, The hardware unit includes a processing module for generating an image signal, and is configured to execute generation and transmission of the image signal in accordance with a synchronization signal from the print engine. It is characterized by.

  Preferably, the hardware unit transmits an image signal to the print engine based on a differential interface method.

  Preferably, the controller is functionally realized by software executed on a host device, and the hardware unit is realized as an external unit connected to the host device by a bus.

  According to such a configuration, it is possible to realize a framework for generating and transmitting an image signal in real time according to a synchronization signal from the print engine, thereby greatly improving the throughput in the printing operation.

  In addition, printing can be executed by generating an image signal in real time without imposing a large load on the host device and depending on the load state of the host device.

  Further, since it is not necessary to provide a print control function and an image processing function inside the printer apparatus as in the prior art, the structure and functions of the printer apparatus can be simplified (the number of parts can be reduced), and manufacturing can be performed. / Maintenance costs can be reduced.

  Further, by adopting a configuration in which the controller and the external board are arranged outside the printer device (separately), the controller and the external board can be shared and used by a plurality of printer devices.

  The hardware unit of the present invention is provided to be interposed between a controller that controls a printing operation and a print engine that executes printing based on an image signal, and the image signal is printed based on the control of the controller. A hardware unit for transmitting to an engine, comprising a processing module for generating an image signal, wherein the image signal is generated and transmitted in accordance with a synchronization signal from the print engine. To do.

  The control method of the present invention includes a controller that controls a printing operation, a print engine that executes printing based on an image signal, and hardware that generates an image signal under the control of the controller and transmits the image signal to the print engine. A signal indicating start of printing from the controller to the print engine via the hardware unit, and generation and transmission of an image signal by the hardware unit. And a step of controlling the hardware unit so as to be executed in synchronization with a synchronization signal transmitted from the print engine in response to a signal indicating start.

  The control method of the present invention can be implemented by a computer, and a computer program therefor can be installed or loaded on the computer through various media such as a CD-ROM, a magnetic disk, a semiconductor memory, and a communication network. It also includes the case where a computer program is recorded and distributed on a printer card or printer option board.

  As described above, according to the present invention, printing can be started without waiting for accumulation of a print image or intermediate code for one page, for example, and high throughput can be realized.

  FIG. 1 is a block diagram showing a hardware configuration of a print system 1 according to an embodiment of the present invention. As shown in FIG. 1, the print system 1 includes a host device 10, an external board 20 connected to the host device 10 by a predetermined standard (for example, PCI bus standard), an external board 20, and a video interface (described later). And a printer device (image forming device) 30 connected via the printer.

  The host device 10 includes a CPU, a ROM, a RAM, a user interface, an interface (for example, a PCI slot) for connecting the external board 20 via a bus, and the like.

  Functionally, the raster image is received from the printer driver 11 and the printer driver 11 that generate a raster image in response to a print request from an application program operating on the host device 10, and the raster image is received from the external board 20 or the printer device 30. A controller 12 for controlling a series of printing operations including the operations is provided (see FIG. 2).

  The printer driver 11 has the same functional configuration as that of a normal printer driver. For example, a RIP (raster image processor) function for generating a raster image based on print target data described in a predetermined printer control language such as Postscript. Etc.

  However, the printer driver 11 does not need to have a function of generating a print image by performing predetermined image processing (halftone processing, color conversion processing, etc.) on the raster image. As will be described later, in the present embodiment, these functions are realized by hardware in the external board 20.

  The controller 12 has the same functional configuration as that of a controller (implemented by a CPU or the like provided in the printer apparatus) that is conventionally arranged in the printer apparatus. For example, the controller 12 is based on an instruction from the printer driver 11 or a user. A function for transmitting a control signal to the printer device 30 (print engine 32) to execute various operations (print control function), and a function for transmitting an image signal in accordance with a synchronization signal from the printer device 30 (print engine 32) (Data transfer control function).

  However, as will be described later, the controller 12 is configured to indirectly transmit a control signal and an image signal to the printer device 30 (print engine 32) via the external board 20, so that the conventional configuration is used. It is different from the controller.

  The functions of the printer driver 11 and the controller 12 are functionally realized by the CPU executing a program stored in a ROM or RAM in the host device 10 or an external storage medium.

  The external board 20 is an external hardware unit including a RAM 21, an image processing module 22, a PWM (Pulse Width Modulation) module 23, a video interface 24, an interface 25 (for example, a PCI interface) for connecting to the host device 10, and the like. . As can be seen from FIGS. 1 and 2, the external board 20 is provided between the controller 12 and the printer device 30 (print engine 32).

  The RAM 21 is a memory in which the raster image generated by the printer driver 11 is stored, and can be configured using, for example, an SDRAM (Synchronous Dynamic Random Access Memory) that can perform burst transfer at high speed.

  The image processing module 22 performs a series of image processing such as halftone processing and color conversion processing on the raster image on the RAM 21 in real time in accordance with the synchronization signal of the printer device 30 (print engine 32), and prints the print image. Dedicated hardware to be generated, which can be configured using, for example, an ASIC.

  The PWM module 23 is dedicated hardware for generating an image signal by modulating a print image by a pulse width modulation method (PWM), and is configured using a general PWM module used in a conventional laser printer or the like. be able to.

  The video interface 24 is an interface based on a transmission format between the external board 20 and the printer device 30 (print engine 32), and is a UART for transmitting a control signal from the external board 20 to the printer device 30 (print engine 32). (Universal Asynchronous Receiver / Transmitter) circuit, a circuit (for example, LVDS circuit) based on a differential interface system for transmitting an image signal from the external board 20 to the printer device 30 (print engine 32), and the like. As the above transmission format, it is desirable to adopt a transmission format that has been used for data transfer between a controller and a print engine, which is conventionally arranged inside the printer apparatus. This is because in the USB (Universal Serial Bus) standard or the like, it is difficult to transmit the image signal in real time without being delayed by the synchronization signal of the print engine.

  The printer device 30 includes a video interface 31, a print engine 32, and the like.

  The video interface 31 is the same as the video interface 24. They are connected by a dedicated cable.

  The print engine 32 is, for example, a normal electrophotographic print engine, and includes an engine driver 33, an engine mechanism unit 34 (laser diode, photoconductor, transfer belt, and their drive units), and the like. The type of print engine may be either a 4-cycle system or a tandem system.

  The engine driver 33 and the engine mechanism unit 34 have the same functional configuration as the normal engine driver and engine mechanism unit. For example, the engine driver 33 functions to update the status of the printer device 30 based on a control signal received via the video interface 31, a sensor signal from the engine mechanism unit 34, and the control signal ( A function of outputting a motor drive signal, a toner control signal, and the like, and a function of transmitting a status and a synchronization signal via the video interface 31.

  Hereinafter, the printing operation in the printing system 1 will be described with reference to the flowchart shown in FIG. In addition, each process (including the partial process to which the code | symbol is not provided) can be arbitrarily changed in order within the range which does not produce contradiction in the processing content, or can be performed in parallel.

  When the printer driver 11 receives a print request from an application program running on the outside or the host device 10, the printer driver 11 notifies the controller 12 of the start of printing (step S100).

  Further, a raster image (for example, a CMYK four-color raster image) is generated by the RIP function based on print target data described in a predetermined printer control language such as PostScript received from the application program, and the RAM of the host device 10 (Step S101). Note that step S101 can be omitted if print target data can be received in the form of a raster image from an application program or the like.

  Upon receiving the print start notification from the printer driver 11, the controller 12 receives an activation signal and, if necessary, from the printer driver 11 via the interface 25 to the external board 20 (image processing module 22, PWM module 23). The printing related information is transmitted (step S102).

  Next, the controller 12 transfers the raster image from the RAM of the host device 10 to the RAM 21 of the external board 20 via the interface 25 (step S103). The printer driver 11 may store the raster image directly in the RAM 21.

  Next, using the UART of the video interface 24, the controller 12 transmits a control signal instructing execution of printing for one page to the printer device 30 (engine driver 33) (step S104).

  When the engine driver 33 receives a control signal indicating printing execution via the video interface 31, the engine driver 33 sets the status to “printing” and outputs a necessary control signal to the engine mechanism unit 34 to prepare for printing. (Step S105).

  When the preparation for printing is completed, each synchronization signal is transmitted to the external board 20 via the video interface 31 based on the sensor signal (main scanning synchronization signal, sub-scanning synchronization signal) from the engine mechanism unit 34 ( Step S106).

  On the other hand, when the synchronization signal is received via the video interface 24, the image processing module 22 activated by the activation signal performs image processing (halftone) on the raster image stored in the RAM 21 in synchronization with the synchronization signal. Processing, color conversion processing, etc.) are executed, and print images are generated in the scanning order (step S107). As described above, since the image processing module 22 is configured as dedicated hardware, a print image can be generated by executing image processing in real time without being delayed by the synchronization signal from the engine driver 33. When there are a plurality of raster images such as CMYK, the order in which the print images are generated is determined according to the type of the print engine 32 (for example, in the case of the 4-cycle method, one page for C And a print image for one page for M is generated).

  When the synchronization signal is received via the video interface 24, the PWM module 23 activated by the activation signal performs pulse width modulation on the print image generated by the image processing module 22 in synchronization with the synchronization signal. Modulation is performed by the method (PWM) to generate an image signal (step S108).

  Then, the differential interface circuit of the video interface 24 transmits the image signal generated by the PWM module 23 to the printer device 30 (engine driver 33) in synchronization with the received synchronization signal (step S109).

  When the engine driver 33 receives an image signal via the video interface 31, the engine driver 33 drives the engine mechanism unit 34 based on the image signal to execute printing (step S110).

  The engine driver 33 stops transmission of each synchronization signal when printing for one page is completed, for example, sets the status to “waiting”, and sends the status to the external board 20 via the video interface 31. The status is transmitted (step S111).

  When the controller 12 receives the “standby” status in the external board 20 (video interface 24), if there is a raster image that has not yet been printed (step S112: YES), the controller 12 performs printing on the raster image in step S103. Alternatively, the process returns to S104.

  As described above, in this embodiment, the host device 10 does not perform image processing by software to generate a print image or image signal, but performs image processing or the like by a hardware unit (external board 20). Since the print image and the image signal are generated, the image signal can be generated at high speed. As a result, a framework for generating and transmitting an image signal in real time according to the synchronization signal from the print engine 32 can be realized, and the throughput in the printing operation can be greatly improved.

  Further, by providing a dedicated hardware unit (image processing module 22) for executing such image processing, image processing by software in the host device 10 becomes unnecessary, which increases the burden on the CPU of the host device 10. Can be reduced. Further, since the image processing is performed without using the CPU resource of the host device 10, the printing process can be executed in real time without being influenced by the CPU load state of the host device 10.

  Further, since the controller 12 is realized on the host device 10 and the external board 20 is connected to the host device 10, a print control function (so-called controller) and an image processing function are provided inside the printer device as in the past. There is no need, the structure and function of the printer device 30 can be simplified (the number of parts can be reduced), and the cost of manufacturing / maintenance can be reduced. Further, by adopting a framework in which the controller 12 and the external board 20 are arranged outside the printer device 30 as described above, the controller 12 and the external board 20 can be shared by a plurality of printer devices 30 and used.

(Other)
The present invention is not limited to the above embodiment and can be applied in various modifications. For example, the external board 20 may be a hardware unit configured to be connectable to the host device 10, and may be configured as an expansion card (such as a PCI card), for example.

  Further, for example, in order to save the capacity of the RAM 21 of the external board 20, the raster image is compressed and stored in the RAM 21, and the image processing module 22 executes decompression processing and image processing in synchronization with the synchronization signal, A configuration may be adopted in which print images are generated in the scanning order.

  Further, for example, the controller 12 not only receives a print start from the printer driver 11 and starts a print operation, but also accepts designation of image data stored in the RAM of the host device 10 from the user and prints directly. A function for starting the operation may be provided.

  Further, for example, in the above-described embodiment, only “printing” and “standby” are described as the statuses set by the engine driver 33, but the engine driver 33 receives a sensor from the engine mechanism unit 34 as in the conventional printer device. Various statuses (for example, “no paper”, “paper jam”, etc.) can be set based on the signal. These statuses are transmitted to the controller 12 in response to a status request from the controller, for example.

  Finally, the present invention may be applied to any color / monochrome printer apparatus, and can also be applied to an image forming apparatus other than the printer apparatus and a print engine other than the electrophotographic system.

1 is a block diagram illustrating a hardware configuration of a print system 1 according to an embodiment of the present invention. 3 is a block diagram illustrating a functional configuration diagram in a host device 10. FIG. 3 is a flowchart for explaining a printing operation in the printing system 1;

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Print system, 10 Host apparatus, 11 Printer driver, 12 Controller, 20 External board, 21 RAM, 22 Image processing module, 23 PWM module, 24 Video interface, 25 Interface for connecting to host apparatus, 30 Printer apparatus, 31 Video interface, 32 print engine, 33 engine driver, 34 engine mechanism

Claims (6)

A printing system comprising: a controller that controls a printing operation; a printing engine that executes printing based on an image signal; and a hardware unit that transmits an image signal to the printing engine under the control of the controller. ,
The hardware system includes a processing module for generating an image signal, and is configured to execute generation and transmission of an image signal in accordance with a synchronization signal from the print engine.   The printing system according to claim 1, wherein the hardware unit transmits an image signal to the print engine based on a differential interface method.   3. The printing system according to claim 1, wherein the controller is functionally realized by software executed on a host device, and the hardware unit is realized as an external unit connected to the host device by a bus. . A hardware unit that is provided between a controller that controls a printing operation and a print engine that executes printing based on an image signal, and that transmits the image signal to the printing engine based on the control of the controller. There,
A hardware unit comprising a processing module for generating an image signal and configured to generate and transmit an image signal in accordance with a synchronization signal from the print engine. A printing system comprising: a controller that controls a printing operation; a printing engine that executes printing based on an image signal; and a hardware unit that generates an image signal under the control of the controller and transmits the image signal to the printing engine. A targeted control method,
Sending a signal indicating the start of printing from the controller to the print engine via the hardware unit;
Controlling the hardware unit such that generation and transmission of an image signal by the hardware unit is executed in synchronization with a synchronization signal transmitted from the print engine in response to a signal indicating the start of printing; A control method comprising:   A program for causing a computer to execute the control method according to claim 5.

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