JPH09114609A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set the optimum size of a reception butter. SOLUTION: A CPU 2 adjusts the size of the reception butter 9 based on whether host I/Fs 6-8 perform bidirectional communication or the communication of only a reception direction in the case of receiving data from host machines 21-25 through the host I/Fs 6-8. Also, based on the kind of the protocol of the host machines 21-25 and an operated emulation program, the size of the reception buffer 9 is adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer that prints based on print data from a host device.

[0002]

2. Description of the Related Art Generally, print data sent from a host device to a printer has various types such as character codes, image data, and control commands. In addition, the communication means between the printer and the host device is capable of bidirectional communication,
When the printer supports the inquiry command, the host device may inquire various information to the printer by the inquiry command. In response to this inquiry command, the printer returns the corresponding information via the communication means.

Data received from the host in the printer is temporarily stored in the reception buffer before being processed by the command interpreter (emulation program). This receive buffer has a dumb-like role so that both processes can proceed smoothly due to the difference between the communication speed of the two and the processing speed of the command analysis unit. Also, when the capacity of this receive buffer is large, Can receive data from the host and store it in this reception buffer without waiting for processing on the interpreter side, which has the advantage of completing the processing on the host side quickly.

[0004]

If the capacity of the reception buffer is large, when the host device sends an inquiry command to the printer, a large amount of data that has not been processed by the command analysis unit is stored in the reception buffer. It may remain. Therefore, in this case, since the response from the printer to the host device in response to the inquiry command comes after processing all the received data before this inquiry command, it is in a state in which the host device is not processed so much in this state. Depending on the situation, there is a problem that an error occurs due to timeout monitoring.

In order to solve such a problem, it is known that the user can set the size of the reception buffer from the operation panel. In such a configuration, a plurality of host I / Fs are connected. When using multiple host devices via a network or the like, it is troublesome for the user to check the optimal size of the receive buffer before using it and to reset it. There is.

In view of the above conventional problems, it is an object of the present invention to provide a printer capable of automatically setting the optimum size of the reception buffer.

[0007]

In order to achieve the above object, the present invention receives data from a host device by performing bidirectional communication or communication only in the receiving direction with a plurality of host devices. The reception based on a plurality of interfaces, a reception buffer for temporarily storing data received via the interfaces, and whether the interface receiving the data performs bidirectional communication or communication in the reception direction only. And a means for adjusting the size of the buffer.

The present invention also provides a plurality of interfaces for receiving data from the host device by performing bidirectional communication or communication only in the receiving direction with the plurality of host devices, and the reception via the interfaces. It is characterized by having a receiving buffer for temporarily storing data and means for adjusting the size of the receiving buffer based on the type of protocol of the destination host device which received the data.

The present invention also provides a plurality of interfaces for receiving data from the host device by performing bidirectional communication or communication only in the receiving direction with the plurality of host devices, and the reception via the interfaces. A receiving buffer for temporarily storing data, a plurality of command interpreting means for interpreting commands of a plurality of destination host devices, and the receiving operation based on which command interpreting means is operating when receiving the data. And a means for adjusting the size of the buffer.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an image processing unit (controller) of a laser beam printer as one embodiment of a printer according to the present invention, and FIG. 2 is an explanation showing a procedure until print data sent from a host machine is printed. 3, FIG. 3 is an explanatory diagram showing the management information of the host buffer of FIG. 1, FIG. 4 is a flowchart for explaining the process of changing the buffer size based on the communication direction, and FIG. 5 is a buffer size based on the partner protocol. Is a flowchart for explaining the processing for changing the buffer size, and FIG. 6 is a flowchart for explaining the processing for changing the buffer size based on the emulation program.

In FIG. 1, the CPU 2 is a controller 1
An instruction for controlling the whole and operating the CPU 2, an emulation program for interpreting the print command and converting it into print image data, and the like are stored in the program ROM 3. The RAM 4 is a memory having a work area for storing temporary information and the like, and the font ROM 5 is a memory for storing character image information.

The host I / Fs 6 to 8 are host machines 21 to 21.
The host I / F 6 is a Centronics I / F that performs unidirectional communication with the host machine 21, and the host I / F 7 is a host machine 22 in this example. Is a RS232C I / F capable of bidirectional communication with the host machine, and the host I / F 8 is a network I / F which communicates with the host machines 23 to 25 via the network 26. The host buffer 9 is a reception buffer for temporarily storing the data received from the host machines 21 to 25.

The panel I / F 10 is an interface section for controlling communication with the operation section 11, and the operation section 11 is composed of a display section showing the printer status and a switch section for the operator to control the printer. The video memory 11 can store print image data in page units,
The video I / F 12 sends the image data in the video memory 11 to the printer engine 13. The printer engine 13 forms the image data sent from the video I / F 12 on a print medium such as paper by a laser beam, an electrophotographic process, or the like. The bus 14 has a CPU 2 and a program RO
M3, RAM 4, font ROM 5, host buffer 9, panel I / F 10 and video memory 11 are connected.

Next, referring to FIG. 2, the host machines 21-
The procedure until the print data sent from 25 is printed will be described. The print data sent from the host machines 21 to 25 is received by the host I / Fs 6 to 8. When the host I / Fs 6 to 8 receive the print data, the CPU 2 is notified of the data reception by interruption. CP
U2 receives the received data by the host I / F6
8 to 8 and once stored in the host buffer 9.

The emulation program 30 is a module that sequentially reads print data from the host buffer 9 and analyzes it to create a print image. Here, the commands sent from the host machines 21 to 25 have several kinds of command systems for each of the host machines 21 to 25, and a plurality of kinds of emulation programs 30 are stored in advance in the program ROM 3 in order to correspond to them. It can be switched through a dedicated command or the operation unit 11.

The print data sent from the host machines 21 to 25 includes: -a character code for specifying a character-image data for printing image data-a graphics command for printing a graphic-printing position Control commands to control the printer, etc.-Contains commands to inquire about the printer status and printer configuration.

The emulation program 30 analyzes and identifies these print data and forms a print image on the video memory 11 page by page. In the case of an inquiry command, the response data is returned to the host machines 21 to 25 via the host I / Fs 6 to 8 that received the inquiry command. Each drawing module performs the actual drawing work in response to an instruction from the emulation program. When drawing a character, the character drawing module 31 is used.
Is a font ROM that stores character image information corresponding to the character code.
5, the print image is drawn on the video memory 11 page by page.

The image drawing module 31 and the graphics drawing module 32 draw the print image on the video memory 11 page by page based on the image data and the graphics data, respectively. When the print image for one page is completed, this print image is displayed on the video memory 11
Alternatively, it is sent to the printer engine 13 via the video I / F 12 and printed on paper or the like.

Next, the host buffer 9 will be described.
t In First Out) format. In order to manage this by a program, it is managed by at least four pieces of information as shown in FIG. 3, and this information includes a head pointer P1 indicating the head address of the host buffer 9, an input pointer P2 indicating the input address of print data, and The output pointer P3 indicates the output address of the print data, and the end pointer P4 indicates the end address of the host buffer 9.

In FIG. 3, in the initial state of the host buffer 9, the input pointer P2 and the output pointer P3 are set to the same value as the head pointer P1.
When the data is received via F6 to 8, the received data is stored in the address indicated by the input pointer P2, and the input pointer P2 is set to the next address. Therefore,
The difference between the values of the input pointer P2 and the output pointer P3 is the number of data in the host buffer 9.

When reading data from the host buffer 9, the data is sequentially fetched from the address indicated by the output pointer P3 within a range not exceeding the input pointer P2, and the value of the output pointer P3 is updated. When the input pointer P2 and the output pointer P3 reach the end pointer P4, the host buffer 9 is circulated and used by moving the pointers P2 and P3 to the head pointer P1.

These pointers P1 to P4 are created as variables on the RAM 4 by the CPU 2 at the time of activation. At this time, the head pointer P1 is set to the head address of the host buffer 9, and the end pointer P4 is set to the head pointer P1. The address obtained by adding the size of the host buffer 9 is set, and the input pointer P2 and the output pointer P3 are set to the same value as the head pointer P1. When data is input / output, the values of the input pointer P2 and the output pointer P3 are changed as described above to manage the buffer 9.

In this embodiment, as an example, two types of size information of the host buffer 9 are prepared in advance. The larger one is used when the communication form with the host machines 21 to 25 is only reception, and the smaller one is the host machines 21 to 2.
It is used in the case of a communication mode in which response data is returned to The former is a case of receiving via the host I / F 6 of Centronics, and the size in this case will be called MAX size in the following description. The latter is a case of receiving via the host I / F 7 of RS232C, and the size in this case is called MIN size. In addition, the network 26,
When receiving via the host I / F 8, there are two types, unidirectional and bidirectional, depending on the host machines 23 to 25.

FIG. 4 shows a host I / F 6 whose communication direction is known,
The process when data is received via 7 is shown. When data is received via the host I / Fs 6 and 7, it is first checked whether bidirectional reception is performed (step S11). here,
As described above, when the host I / Fs 6 to 8 receive the data, the CPU 2 notifies the CPU 2 of the data reception by the interrupt. Therefore, the CPU 2 can determine the communication mode depending on which of the host I / Fs 6 to 8 is the interrupt.

When it is determined that the reception is bidirectional in step S11, it is checked whether the size of the host buffer 9 is set to the MIN size (step S).
12). If the MIN size is set, the received data is stored in the host buffer 9 of the MIN size (step S13). On the other hand, if the MIN size is not set, the host buffer 9 becomes empty. It waits (step S14), and when it becomes empty, the end pointer P
4 is set for the MIN size (step S15), and the process proceeds to step S13 to store the received data in the host buffer 9 of the MIN size.

On the other hand, when the bidirectional reception is not performed in step S11, the size of the host buffer 9 is M.
It is checked whether the AX size is set (step S16). If it is set to the MAX size, the received data is stored in the host buffer 9 of that MAX size (step S13). On the other hand, if it is not set to the MAX size, the host buffer 9 becomes empty. It waits (step S17), and when it becomes empty, sets the end pointer P4 for MAX size (step S1).
8) Go to step S13 and set the received data to MAX
The size is stored in the host buffer 9.

Next, the processing when data is received via the network 26 and the host I / F 8 whose communication direction is unknown will be described with reference to FIGS. Here, when performing communication via the network 26, the host machines 23 to
The protocol (communication protocol) differs depending on the 25 types. For example, a host machine that uses the Appletalk protocol of the Macintosh company inquires various information of the printer at the time of printing and creates print data suitable for it.
The host machine that uses the TCP / IP protocol does not make an inquiry, but only transfers print data.

Therefore, in the processing shown in FIG. 5, when data is received via the network I / F 8, first, the destination host machines 23 to 25 check whether or not the protocol requires transmission of response data (step S21). ). When it is determined that the protocol requires the transmission of the response data, it is checked whether or not the size of the host buffer 9 is set to the MIN size as in the case shown in FIG. 4 (step S22), and the MIN is set. If the size is set, the received data is stored in the host buffer 9 of the MIN size (step S23). On the other hand, if the MIN size is not set, the host buffer 9 waits until it becomes empty ( At step S24), when it becomes empty, the end pointer P4 is set for the MIN size (step S2).
5) Go to step S23 and set the received data to the MIN
The size is stored in the host buffer 9.

Also, when the response data is not required to be transmitted in step S21, it is similarly checked whether or not the size of the host buffer 9 is set to the MAX size (step S26), and the size is changed to the MAX size. If it is set, the received data is stored in the host buffer 9 of that MAX size (step S23), while if it is not set to the MAX size, it waits until the host buffer 9 becomes empty (step S27). ), When it becomes empty, the end pointer P4 is set for the MAX size (step S28), and the process proceeds to step S23 to store the received data in the host buffer 9 of the MAX size.

In the process shown in FIG. 6, when the emulation program is changed based on the destination,
It is checked whether the emulation program has an inquiry command (step S31). When it is determined that the emulation program has an inquiry command, it is checked whether or not the size of the host buffer 9 is set to the MIN size as in the case shown in FIGS. 4 and 5 (step S32). If the MIN size is set, the received data is stored in the host buffer 9 of the MIN size (step S33),
On the other hand, if the MIN size is not set, the host buffer 9 waits until it becomes empty (step S34),
When it becomes empty, the end pointer P4 is set for the MIN size (step S35), and the process proceeds to step S33 to store the received data in the host buffer 9 of the MIN size.

Similarly, if the emulation program does not have an inquiry command in step S31, it is similarly checked whether the size of the host buffer 9 is set to the MAX size (step S3).
6) If the maximum size is set, the received data is stored in the maximum size host buffer 9 (step S33). On the other hand, if the maximum size is not set, the host buffer 9 becomes empty. Waits until (step S37) and becomes empty, the end pointer P4 is set to MAX.
Set for size (step S38), step S33
Then, the received data is stored in the host buffer 9 of the MAX size.

[0032]

As described above, according to the present invention, whether the interface that receives data performs bidirectional communication,
Alternatively, since the size of the reception buffer is adjusted based on whether communication is performed only in the reception direction, the optimum size of the reception buffer can be automatically set.

Further, according to the present invention, the size of the receiving buffer is adjusted based on the type of protocol of the destination host device which received the data, so that the optimum size of the receiving buffer can be automatically set.

The present invention also adjusts the size of the receive buffer based on which command interpreting means is operating when receiving data, so that the optimum size of the receive buffer is automatically set. You can

[Brief description of the drawings]

FIG. 1 is a block diagram showing an image processing unit (controller) of a laser beam printer as an embodiment of a printer according to the present invention.

FIG. 2 is an explanatory diagram showing a procedure until print data sent from a host machine is printed.

FIG. 3 is an explanatory diagram showing management information of a host buffer of FIG.

FIG. 4 is a flowchart illustrating a process of changing a buffer size based on a communication direction.

FIG. 5 is a flowchart for explaining a process of changing a buffer size based on a partner protocol.

FIG. 6 is a flowchart illustrating a process of changing a buffer size based on an emulation program.

[Explanation of symbols]

 2 CPU 3 program ROM 9 host buffer 6-8 host I / F 21-25 host machine

Claims (3)

[Claims] 1. A plurality of interfaces for receiving data from a host device by performing two-way communication or communication only in the receiving direction with a plurality of host devices, and temporarily storing data received via the interfaces. A printer having a receiving buffer for storing, and means for adjusting the size of the receiving buffer based on whether the interface receiving the data performs bidirectional communication or communication in the receiving direction only. 2. A plurality of interfaces for receiving data from the host device by performing two-way communication or communication only in the receiving direction with the plurality of host devices, and data received via the interfaces. And a means for adjusting the size of the reception buffer based on the protocol type of the destination host device that received the data. 3. A plurality of interfaces that receive data from the host device by performing bidirectional communication or communication only in the receiving direction with the plurality of host devices, and temporarily store the data received via the interfaces. A receive buffer for storing, a plurality of command interpreting means for interpreting commands of a plurality of destination host devices, and a size of the receive buffer based on which command interpreting means operates when receiving data. And a means for adjusting the height.