JPH11203067A - Printer control system, printer, host computer, printing method and storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer control system which can eliminate interruption of data transfer from a host computer to a printer. SOLUTION: In this printer control system, a host computer 200 confirms a current communication state and sends print data to a printer 100 through synchronous communication if available. If synchronous communication is not available, it's checked whether the print data can be sent through asynchronous communication. If the print data can be sent through asynchronous communication, the print data are sent to the printer 100 through asynchronous communication. If the print data cannot be sent through asynchronous communication, transfer of the print data is suspended for a set time-out period until synchronous communication is available. In this time-out mode, the print data are converted into another data of an appropriate form suitable for asynchronous communication. Then the converted print data are sent to the printer 100 through asynchronous communication.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control system in which a printer is connected to a host computer via an interface capable of synchronous communication and asynchronous communication.
The present invention relates to a printer, a host computer, a printing method, and a storage medium.

[0002]

2. Description of the Related Art In recent years, as a data processing system, a bidirectional interface (for example, IEEE139) capable of performing synchronous communication and asynchronous communication with a host computer has been known.
4, a printer connected via USB), the output information input from the host computer is analyzed on the printer side, and is developed into bitmap data as output data of a printer engine (for example, a laser beam printer). A printer control system for performing image recording by scanning a photosensitive drum with a laser beam modulated based on the development data and exposing the same to a photosensitive drum is known.

[0003] Such a printer control system is configured to be able to process a plurality of printer control language systems when the printer has an emulation function.
The printing process can be executed while switching between the emulation mode and the native mode according to the application executed by the user. Here, the printer is provided with a switch for switching the control language of the printer and a card slot for giving a switching instruction in advance.

In recent years, interfaces capable of performing synchronous communication have been available. Synchronous communication is a communication method that guarantees that a predetermined minimum amount of data can be transferred within a certain period of time, and can be transferred at a high communication speed.

[0005] Synchronous communication having such characteristics is used for print processing for printing in synchronization with the paper transport speed of a printer, such as a video printer, and print processing for transmitting a large amount of print data, such as color printing. Have been.

[0006]

However, the above-described printer control system has the following problems, and improvements have been demanded. That is, the ability to transfer a minimum amount of data determined within a certain period of time by synchronous communication means that the interface bus is occupied during that time, and synchronous communication can be inevitably performed by one interface. The number is limited. In other words, there is a problem that even if an attempt is made to perform synchronous communication, communication cannot be performed at all if all synchronous communication rights are used by another device.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printer control system, a printer, a host computer, a printing method, and a storage medium that can prevent data transfer from a host computer to a printer from being stopped. .

[0008]

In order to achieve the above object, a printer control system according to a first aspect of the present invention includes a printer connected to a host computer via an interface capable of synchronous communication and asynchronous communication. The printer control system further includes a selection unit for selecting a communication method of print data transmitted from the host computer to the printer via the interface, to either the synchronous communication or the asynchronous communication.

According to a second aspect of the present invention, there is provided a printer control system in which a printer is connected to a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication, wherein the synchronous communication is performed via the bidirectional interface. Synchronous communication determining means for determining whether or not the synchronous communication is possible, and when it is determined that the synchronous communication is possible, transmitting the print data from the host computer to the printer by the synchronous communication; A data transmission unit that transmits the print data from the host computer to the printer by the asynchronous communication when it is determined that the printing is not possible.

According to a third aspect of the present invention, in the printer control system according to the second aspect, when it is determined that the synchronous communication is not possible, it is determined whether the print data is data capable of the asynchronous communication. And a standby unit that waits for a predetermined time until the synchronous communication becomes possible if the data is not data that can be asynchronously communicated.

According to a fourth aspect of the present invention, in the printer control system according to the third aspect, when the synchronous communication is not enabled after the lapse of the predetermined time, the print data can be printed by the asynchronous communication. Data conversion means for converting data into data is provided.

According to a fifth aspect of the present invention, in the printer control system according to the fourth aspect, the printer determines whether or not the print data has been received from the host computer by the synchronous communication. And video signal determination means for determining whether the received print data is a video signal, and when the print data is received by the asynchronous communication, or when the print data is not a video signal, Rasterizing means for performing a rasterizing process.

The printer according to claim 6, wherein the printer is connected to the host computer via a bidirectional interface capable of synchronous communication and asynchronous communication. Reception determination means for determining whether print data has been received, video signal determination means for determining whether the received print data is a video signal, and when the print data is received by the asynchronous communication, Alternatively, when the print data is not a video signal, a rasterization processing unit for performing a rasterization process on the print data is provided.

[0014] The host computer according to claim 7 is
A host computer connected to the printer via a bidirectional interface capable of synchronous communication and asynchronous communication; a synchronous communication determining means for determining whether or not the synchronous communication is possible via the bidirectional interface; When it is determined that the communication is possible, the print data is transmitted to the printer by the synchronous communication, and when it is determined that the synchronous communication is not possible, the print data is transmitted to the printer by the asynchronous communication. Data transmission means.

In a printing method according to an eighth aspect of the present invention, there is provided a printing method for printing, by a printer, print data sent from a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication. It is determined whether or not the synchronous communication is possible via the bidirectional interface. If it is determined that the synchronous communication is possible, the print data is transmitted to the printer by the synchronous communication while the synchronous communication is performed. If it is determined that communication is not possible, the print data is transmitted to the printer by the asynchronous communication, and the printer receives the print data from the host computer through the bidirectional interface by the synchronous communication. And determining whether the received print data is a video signal. Determine if receiving the print data by the asynchronous communication, or the print data may not be a video signal, and performing the rasterizing process of the print data.

According to a ninth aspect of the present invention, there is provided a storage medium for storing a program describing a procedure for printing, by a printer, print data transmitted from a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication. In the medium, the program includes a step of determining whether the synchronous communication is possible via the bidirectional interface, and a step of determining whether the synchronous communication is possible. A step of transmitting the print data to the printer by the asynchronous communication when it is determined that the synchronous communication is not possible, and a step of transmitting the print data to the printer by the synchronous communication from the host computer via the bidirectional interface. Determining whether or not the print data has been received, and A step of determining whether or not the data is a video signal, and a step of performing a rasterizing process on the print data when the print data is received by the asynchronous communication or when the print data is not a video signal. It is characterized by.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A printer control system according to the present invention,
An embodiment of a printer, a host computer, a printing method, and a storage medium will be described. A laser beam printer is used in the printer control system of the present embodiment. First, the configuration of the laser beam printer will be described.

FIG. 1 is a sectional view showing the configuration of the laser beam printer according to the embodiment. In the figure, 100
Is a laser beam printer (LBP) main body, which inputs and stores print information such as character codes, form information or macro instructions supplied from an externally connected host computer, and responds according to the information. A character pattern, a form pattern, and the like are created, and an image is formed on a recording medium such as recording paper.

Reference numeral 12 denotes an operation panel on which operation switches and an LED display are arranged, and 1 denotes a printer control unit for controlling the overall control of the LBP main body 100 and analyzing character information supplied from a host computer. The printer control unit 1 mainly converts character information into a video signal of a corresponding character pattern and outputs a laser driver 2.

The laser driver 2 is a circuit for driving the semiconductor laser 3, and switches on and off the laser light 4 emitted from the semiconductor laser 3 according to an input video signal.

The laser beam 4 is oscillated in the left-right direction by the rotary polygon mirror 5 to scan and expose the electrostatic drum 6 to the light. As a result, an electrostatic latent image of a character pattern is formed on the electrostatic drum 6. This latent image is developed by a developing unit 7 provided around the electrostatic drum 6 and then transferred to a recording sheet.

A cut sheet is used as the recording paper.
The cut sheet recording paper is stored in a paper cassette 8 mounted on the LBP main body 100, taken into the apparatus by a paper feed roller 11, and supplied to the electrostatic drum 6.

The LBP main body 100 has at least one or more card slots (not shown), and is configured so that an option card and a control card (emulation card) having a different language system can be connected in addition to a built-in font.

FIG. 2 is a block diagram showing an electrical configuration of the printer control system. In the figure, reference numeral 200 denotes a host computer, which is a program ROM of the ROM 24.
Graphics based on document processing programs stored in
The system includes a CPU 22 that executes processing of a document in which images, characters, tables (including spreadsheets and the like) are mixed, and the CPU 22 comprehensively controls each device connected to the system device 25.

The program RO of the ROM 24
M stores a control program of the CPU 22 and the like.
The font ROM used for document processing is stored in the font ROM of the M24.
The OM stores various data used when performing document processing or the like.

Reference numeral 23 denotes a RAM, which functions as a main memory of the CPU 22, a work area, and the like. Reference numeral 26 denotes a keyboard controller (KBC), and a keyboard (KB) 3
0 or key input from a pointing device (not shown) is controlled.

Reference numeral 27 denotes a CRT controller (CRTC), which controls display on a CRT display (CRT) 31. Reference numeral 28 denotes a memory controller (MC) which controls access to an external memory 32 such as a hard disk (HD) or a floppy disk (FD) for storing a boot program, various applications, font data, user files, edited files, and the like. .

Reference numerals 29 and 46 denote a host I / O control unit and a printer I / O control unit for controlling I / O between devices.
In this part, control of synchronous communication and asynchronous communication is performed via the signal line 60. Specifically, a bidirectional interface such as IEEE1394 can be mentioned, but any type of interface can be used as long as the interface can perform synchronous communication and asynchronous communication. In addition, information on whether synchronous communication is possible or not is managed in this part. Other processing units can obtain the information by issuing a communication request or the like to this control unit. Needless to say, the control may be performed by a unique data stack (not shown).

On the other hand, in the printer (LBP main body) 100, reference numeral 42 denotes a printer CPU, which is connected to the system bus 45 based on a control program or the like stored in the program ROM of the ROM 44 or a control program or the like stored in the external memory 51. A print unit (printer engine) 4 that controls access to various connected devices as a whole and is connected via a print unit I / O interface 47
9 outputs an image signal as output information.

The program RO in the ROM 44 is
In M, a control program and the like to be described later executed by the CPU 42 are stored. For a printer without an external memory 51 such as a hard disk, the data RO
In M, information used on the host computer 200 and the like are stored.

The CPU 42 can communicate with the host computer 200 via an input (printer IO control) unit 46, and can communicate information and the like in the printer to the host computer 200.

Reference numeral 43 denotes a RAM functioning as a main memory, a work area, and the like of the CPU 42, which is designed so that the memory capacity can be expanded by an optional RAM connected to an additional port (not shown). In the RAM 43, an NVRAM or the like is used as an output information development area and an environment data storage area.

The access to the external memory 51 such as a hard disk (HD) and an IC card is controlled by a memory controller (MC) 48. The transmission buffer is created here. The external memory 51 is connected as an option, and stores font data, an emulation program, form data, and the like.

The number of external memories is not limited to one. At least one external memory is provided so that a plurality of external memories storing an option card and a program for interpreting a printer control language of a different language system in addition to a built-in font can be connected. You may comprise. Furthermore, it has a not-shown NVRAM,
The printer mode setting information from the operation panel 12 may be stored.

Reference numeral 12 denotes the above-described operation panel (operation unit). The operation panel 12 is provided with operation switches, an LED display machine, and the like.

FIG. 3 is a flowchart showing the procedure for switching between synchronous communication and asynchronous communication and for converting print data. This processing program is stored in the ROM 24 in the host computer 200 as described above.
It is stored in the OM and executed by the CPU 22.

First, a synchronous communication request is issued to the host IO controller 29 (step S1). The current communication state is confirmed (step S2), and it is determined whether or not synchronous communication is possible (step S3).

If synchronous communication is possible, print data is transmitted to the printer 100 by synchronous communication (step S).
9), end the processing.

On the other hand, if synchronous communication is not possible in step S3, it is checked whether or not the print data is asynchronously communicable (step S4). Here, the print data that cannot be asynchronously communicated is print data of a video printer system or data whose data amount is too large and whose processing is too slow in data transmission by asynchronous communication.

If the print data is asynchronous communication,
The print data is transmitted to the printer 100 via the asynchronous communication (step S10), and the process ends.

On the other hand, if the print data cannot be asynchronously communicated, the process waits until synchronous communication becomes possible until the set timeout time (steps S5 and S6). The timeout period is set to the host computer 200, the printer 100,
It is set to an appropriate value depending on the performance of the bidirectional interface.

When the synchronous communication is enabled within the timeout period, the print data is transferred to the printer 100 by the synchronous communication.
(Step S11), and the process ends.

On the other hand, if synchronous communication is not possible in step S6 and a timeout occurs, the print data is converted into an appropriate data format for asynchronous communication (step S7). Data format conversion is performed, for example, in the case of print data of a video printer system, by using a page description language PDL (Page Discrip
This is performed by changing the data to intermediate data called an “Interaction Language” (PDL method). The PDL print data is rasterized in the printer 100. If the print data has a large data amount, the data format is converted by a process of reducing the data amount by reducing the resolution and the gradation.

The print data converted in step S7 is transmitted to the printer 100 by asynchronous communication (step S7).
8), end the process.

FIG. 4 is a flowchart showing a print processing procedure for print data transmitted by synchronous communication or asynchronous communication. This processing program is executed by the printer 100
The program is stored in the program ROM of the ROM 44 and executed by the CPU 42.

First, reception of print data is started (step S21). It is determined whether or not the communication is synchronous communication (step S22). If it is determined that the communication is not synchronous communication, for example, since the PDL method is used, one page or all data is received (step S25), and the received data is rasterized (step S26). Then, it is converted into a video signal and transferred to the printing unit 49 (step S2).
7) Printing is performed (step S31).

On the other hand, if it is determined in step S22 that the communication is synchronous communication, it is determined whether or not the print data is of the video printer type (step S23). In the case of the video printer system, the data is converted into a video signal while being received and transferred to the printing unit 49 (step S24), and printing is performed (step S31).

On the other hand, if the video printer system is not used in step S23, one page or all data is received (step S28), the received data is rasterized (step S29), converted into a video signal, and printed. 49 (step S30) and print (step S31).

As described above, in the printer control system according to the present embodiment, the data transfer from the host computer 200 to the printer 100 is stopped by changing the transfer method of the two synchronous communication and the asynchronous communication according to the situation. Can be prevented.

The printer is not limited to a laser beam printer, but may be an ink jet printer or a printer of another printing system.

The present invention is applicable to a single device, a system including a plurality of devices, and a system in which processing is performed via a network such as a LAN.

Further, it goes without saying that the present invention can be applied to the case where the present invention is achieved by supplying a program to a system or an apparatus. In this case, by reading out a storage medium storing a program represented by software for achieving the present invention into a system or a device, the system or the device can enjoy the effects of the present invention. RO as the storage medium
M, for example, floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, DVD, magnetic tape, nonvolatile memory card, or the like can be used.

[0053]

According to the printer control system of the first aspect of the present invention, the communication system of the print data transmitted from the host computer to the printer via the interface by the selection means is controlled by the synchronous communication and the communication method. Since one of the asynchronous communication methods is selected, the transfer of data from the host computer to the printer can be prevented from being stopped by changing the two transfer methods according to the situation.

According to the printer control system of the present invention, whether the synchronous communication is possible through the bidirectional interface is determined by the synchronous communication determining means, and the synchronous communication is determined by the data transmitting means. When it is determined that the communication is possible, the host computer transmits the print data to the printer by the synchronous communication, while when it is determined that the synchronous communication is not possible, the host computer transmits the print data to the printer by the asynchronous communication. Since the print data is transmitted, the print data generated by the host computer is transmitted to the printer by synchronous communication when synchronous communication is possible, and is transmitted to the printer by asynchronous communication when synchronous communication is not possible. Causes the transfer of data from the host computer to the printer to stop It is possible to prevent the theft.

As described above, since the number of synchronous communication that can be performed by one interface that can perform synchronous communication is limited, when all synchronous communication rights are used between other devices, a state where the synchronous communication cannot be used is avoided. For this purpose, asynchronous communication provided simultaneously with an interface capable of synchronous communication is used. Asynchronous communication is a transfer method in which data is transferred using the bus time even if the bus is available for a short time. Naturally, it is not possible to transfer a predetermined amount of data within a certain time. The transfer rate is low, but the transfer is always possible. Therefore, by changing the two transfer methods according to the situation, it is possible to prevent the data transfer from the host computer to the printer from being stopped. it can. The same effect can be obtained by the host computer according to the seventh aspect and the printing method according to the eighth aspect.

According to the printer control system of the third aspect, when it is determined that the synchronous communication is not possible,
The data discriminating means discriminates whether or not the print data is data capable of asynchronous communication. If the data is not data capable of asynchronous communication, the standby means waits for a predetermined time until the synchronous communication becomes possible. The possibility of transfer by communication can be increased.

According to the printer control system of the fourth aspect, if the synchronous communication is not enabled even after the predetermined time has elapsed, the print data is converted into the asynchronously communicable print data by the data conversion means. Therefore, by converting the data into an appropriate data format for asynchronous communication and transmitting the data to the printer, it is possible to prevent improper printing.

According to the printer control system of the present invention, the printer determines whether or not the print data has been received from the host computer by the synchronous communication by the reception determining means, and the video signal determining means. It is determined whether or not the received print data is a video signal, and if the print data is received by the asynchronous communication, or if the print data is not a video signal, the rasterization processing unit performs rasterization processing of the print data. Therefore, print data received by synchronous communication and asynchronous communication can be correctly printed.
A similar effect can be obtained in the printer according to the sixth aspect.

According to the storage medium of the ninth aspect, there is stored a program in which a procedure for printing, by a printer, print data sent from a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication is stored. A storage medium that performs a step of determining whether or not the synchronous communication is possible via the bidirectional interface; and a step of: determining that the synchronous communication is possible if the synchronous communication is determined to be possible. A step of transmitting data to the printer, a step of transmitting the print data to the printer by the asynchronous communication when the synchronous communication is determined to be impossible, and a step of transmitting the bidirectional interface from the host computer by the synchronous communication. Determining whether or not the print data has been received via the A procedure for determining whether or not the print data is a video signal, and a procedure for performing a rasterizing process on the print data when the print data is received by the asynchronous communication or when the print data is not a video signal. Since it is included in the printer control system, the scalability and versatility can be enhanced by being interchangeably mounted on the printer control system.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a laser beam printer according to an embodiment.

FIG. 2 is a block diagram illustrating an electrical configuration of the printer control system.

FIG. 3 is a flowchart illustrating a procedure for switching between synchronous communication and asynchronous communication and a procedure for converting print data.

FIG. 4 is a flowchart illustrating a print processing procedure of print data transmitted by synchronous communication or asynchronous communication.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 laser beam printer main body (printer) 200 host computer 22, 42 CPU 24, 44 ROM 29 host IO control unit 46 printer IO control unit 60 signal line

Claims (9)

[Claims] 1. A printer control system in which a printer is connected to a host computer via an interface capable of synchronous communication and asynchronous communication, wherein a communication method of print data transmitted from the host computer to the printer via the interface is provided. A printer control system comprising a selection unit for selecting one of the synchronous communication and the asynchronous communication. 2. In a printer control system in which a printer is connected to a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication, it is determined whether or not the synchronous communication is possible via the bidirectional interface. Synchronous communication determination means, when it is determined that the synchronous communication is possible, while transmitting the print data from the host computer to the printer by the synchronous communication, when it is determined that the synchronous communication is not possible, A printer control system comprising: a data transmission unit configured to transmit the print data from the host computer to the printer by the asynchronous communication. 3. A data discriminating means for judging whether or not the print data is data capable of asynchronous communication when it is determined that the synchronous communication is not possible, and 3. The printer control system according to claim 2, further comprising a standby unit that waits for a predetermined time until synchronous communication is enabled. 4. A data conversion means for converting the print data into print data capable of asynchronous communication when the synchronous communication is not enabled even after the predetermined time has elapsed. A printer control system as described. 5. The printer according to claim 1, wherein the printer determines whether the print data is received from the host computer by the synchronous communication, and determines whether the received print data is a video signal. A video signal determination unit, when the print data is received by the asynchronous communication,
5. The printer control system according to claim 4, further comprising: a rasterizing unit that performs a rasterizing process on the print data when the print data is not a video signal. 6. A printer connected to a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication, and whether or not the print data has been received from the host computer via the bidirectional interface by the synchronous communication. Receiving determination means for determining whether or not the received print data is a video signal; andvideo signal determination means for determining whether the received print data is a video signal;
Alternatively, if the print data is not a video signal, the printer further comprises a rasterizing processing means for performing a rasterizing process on the print data. 7. A host computer connected to a printer via a bidirectional interface capable of synchronous communication and asynchronous communication, wherein a synchronous communication determination for determining whether said synchronous communication is possible via said bidirectional interface. Means, when it is determined that the synchronous communication is possible, the print data is transmitted to the printer by the synchronous communication, while when it is determined that the synchronous communication is not possible, the print data is transmitted by the asynchronous communication. A host computer comprising: a data transmission unit that transmits the data to the printer. 8. A printing method for printing, by a printer, print data sent from a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication, wherein the host computer comprises: It is determined whether or not communication is possible.If it is determined that the synchronous communication is possible, the print data is transmitted to the printer by the synchronous communication, while it is determined that the synchronous communication is not possible. In the case, the print data is transmitted to the printer by the asynchronous communication, and the printer determines whether or not the print data is received from the host computer through the bidirectional interface by the synchronous communication. Determining whether the print data is a video signal; When receiving the print data by Shin,
Alternatively, when the print data is not a video signal, a rasterizing process of the print data is performed. 9. A storage medium storing a program describing a procedure for printing, by a printer, print data sent from a host computer via a bidirectional interface capable of synchronous communication and asynchronous communication, wherein the program comprises: A step of determining whether the synchronous communication is possible via the bidirectional interface, and a step of transmitting print data to the printer by the synchronous communication when the synchronous communication is determined to be possible, A step of transmitting the print data to the printer by the asynchronous communication when it is determined that the synchronous communication is not possible; and a step of receiving the print data from the host computer through the bidirectional interface by the synchronous communication. Determining whether or not the received print data is a video signal. Determining whether or not the print data has been received by the asynchronous communication;
Alternatively, when the print data is not a video signal, a procedure for performing a rasterizing process on the print data is included.