JPH09237167A - Printing method and printing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate memory deficiency at a printer side without increasing memory capacity at the printer side. SOLUTION: At the time of memory deficiency is caused at the printer 30 side, a memory securing instruction for securing a printer memory area is outputted to a host 20 so as to wait for the presuppose of memory securing completion. When the response of memory securing completion is returned, data to be transferred is selected and outputted together with a writing instruction to the host 20 side. When data saved at the host 20 side is required, a data reading instruction is outputted and data is written in RAM 43 of the print 30 side when data reading response is returned. When the memory area is not required to be secured at the host 20 side, a memory releasing instruction is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention stores image data in a memory on the printer side based on data sent from a host computer, and performs printing based on the stored image data. The present invention relates to a method and a printing system that implements the printing method.

[0002]

2. Description of the Related Art Conventionally, a page printer represented by a laser printer needs a RAM capable of sufficiently storing one page of image information, and data exceeding the capacity of the printer RAM is sent from the host computer. When it comes, it runs out of memory and an error occurs. Efforts have been made to solve the memory shortage by using data compression technology, but on the other hand, it is necessary to reduce the memory capacity as much as possible for cost reduction, and the problem of memory shortage still remains.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the memory shortage on the printer side without increasing the memory capacity on the printer side.

[0004]

According to the printing method of the present invention, image data is stored in a memory on the printer side based on data sent from a host computer, and the storage is performed. In the printing method that executes printing based on the image data that was created, save some of the data that should be secured on the printer side to the memory on the host computer side as necessary. In addition, when the saved data is needed on the printer side, the data is returned to the printer side.

For example, a hard disk on the host side or RA
A part of the data to be secured on the printer side is saved in M or the like. By saving a part of the data to the host side in this way, it is possible to expand the usable memory on the printer side and solve the memory shortage. Then, the saved data is returned to the printer side as necessary, so that the saving of the data does not cause a problem such as printing failure.

In the printing system of the present invention, image data is stored in the memory on the printer side based on the data sent from the host computer, and printing is executed based on the stored image data. In the printing system, the host computer and the printer are connected so as to be capable of bidirectional communication, and a part of the data to be secured on the printer side is stored in the host computer side as necessary. And a data returning means for returning the data to the printer side when the printer side needs the data saved in the memory of the host computer side. .

According to this printing system, the data saving means saves a part of the data to be secured on the printer side to the host computer side as necessary, and when this data is needed on the printer side, The data returning means returns the data to the printer side. This realizes the method of the present invention.

In this printing system, it is preferable to provide a memory shortage determination means for operating the data saving means when the printer runs out of memory. By doing so, it is not necessary to save and restore data more than necessary, and the operating efficiency of the entire system is not hindered.

In these printing systems of the present invention, more specifically, the data saving means has, on the printer side, a memory area for storing a part of data to be secured on the printer side. The memory allocation command means for outputting a memory allocation command to be allocated to the host computer side and the data transfer means for transferring the partial data to the host computer side are provided, and the memory allocation command is provided to the host computer side. And a data depositing means for storing the data output by the data transfer means in the secured memory area. The means causes the printer side to return necessary data from the secured memory area. And a data retransfer means for reading the corresponding data from the memory area and transferring it to the printer when the return command is received. It may be configured by being provided.

According to this system, a memory area is secured on the host side in response to a memory securing command from the printer side, and the printer side saves data to be saved in the memory area. And when the data is needed,
It is possible to output a return command from the printer side, notify the host side of this, and cause the host side to return the data.

In this case, the printer side is provided with a memory release command output means for outputting a memory release command for releasing the memory area secured by the host computer side, and the memory release command is issued on the host computer side. It is preferable to provide a memory releasing means for releasing the reserved memory area when receiving. By doing so, the host side does not need to unnecessarily reserve a memory area for saving data, and utilization of the memory on the host side is not hindered.

In the printing system of the present invention, the printer is a page printer having a page memory, and the data to be saved is data to be secured in a storage area other than the page memory on the printer side. Good. For example, data such as a pattern cache, a font cache, page data, graphic data, a download pattern, a download macro, and a download font can be given. The reason why the page memory itself is not saved is that the image data necessary for printing is always expanded here, and it becomes necessary to restore it immediately after saving. On the other hand, the illustrated pattern cache and the like are not always necessary for printing, and thus may be temporarily saved.

In this case, when there are a plurality of types of data to be saved, it is preferable to provide a save priority determining means for determining a save priority according to the type of data. In this case, the priority order of saving may be set considering the frequency required for printing as a characteristic of data.

[0014]

EXAMPLES Examples will be described below with reference to the drawings in order to make the embodiments of the present invention more understandable. The printer system 10 of the embodiment includes a print host 2 as shown in FIG.
0 and a laser printer 30. The print host 20 and the laser printer 30 are connected via a Centronics cable 15 for parallel data transmission / reception so as to be capable of bidirectional communication.

The host 20 includes a CPU 21, a ROM 22,
A personal computer including a RAM 23, a hard disk 24, an input / output port 25, and the like, and is configured to output PDL (Page Description Language) type print data and command data (hereinafter, “PDL output”, “PDL output”). "Data" etc.).

The laser printer 30 is provided with an exposure device, a photoconductor, a developing device, a transfer device, a fixing device, etc., and an engine section 35 for forming an image on a sheet by electrophotography.
Controller unit 40 for driving and controlling the engine unit 35
Consists of The controller unit 40 includes a CPU 41, RO
The M42, the RAM 43, the line scan buffer 44, the drive circuit 45, the input / output port 46 and the like are mainly configured.
Of these, the RAM 43 is the PDL received from the host 20.
It is used to store data once and also to store image data expanded by command execution. Also,
It is also used to store data such as pattern cache, font cache, page data, graphic data, download patterns, download macros, and download fonts.

Here, the pattern cache and the like will be described. Pattern cache A pattern (pattern) specified by the host is expanded into a bitmap for printing and the result is temporarily stored in memory. This helps to avoid the need to deploy again when the host specifies the same pattern again.

Font cache According to the type and size of characters specified by the host, the result of scalable expansion into a bitmap for printing is temporarily stored in memory. By doing this, it is not necessary to expand the character again when the same character is specified by the host.

Page data Completely bitmapped data for one page immediately before printing. This data is output to the laser beam as it is. Shape data Intermediate shape data before expanding to page memory. The shape of the figure is represented by numerical values (coordinates). It is not expanded until printing.

Download pattern A pattern downloaded from the host. This data is not immediately expanded into print data, but is referred to when the drawing data for using the pattern is next sent from the host.

Similar to the download macro. A macro is an encapsulation of a series of procedures, and when using the same series of procedures over and over, it is not necessary to repeatedly send a large amount of data from the host.

Similar to download font. The print host 20 and the laser printer 30 execute printing by the following processing.

First, the control processing on the laser printer 30 side will be described. On the laser printer 30 side, when the PDL data from the host 20 is received, as shown in FIG.
The command included in this is executed to expand the print data into image data (S10, S20). Then, as a result of this data expansion, it is determined whether or not there is a memory shortage in the RAM 43 (S30). "Memory shortage" here means that there is not enough free space when trying to secure a memory of the size required for data expansion.

If the memory is insufficient, the host 20 outputs a memory reservation command for reserving a memory area for the printer (S40). And the host 20
It waits for a response from the device indicating that the memory allocation is completed (S50). When the memory allocation completion response is returned, select the data to be transferred to the host 20 side (S
60), this data is output to the host 20 side together with the write command (S70). The data to be transferred is selected from the pattern cache and the like. The priority of selection is
Download font, download macro, download pattern, graphic data, page data,
The order is font cache and pattern cache. This priority is determined by the relationship with the frequency of use. The lower the frequency of use, the earlier the data is saved to the host 20 side.

On the other hand, when the data saved to the host 20 side becomes necessary (S80 = YES), the host 20
A data read command is output to (S90).
Then, it waits for a data read response to be returned from the host 20 (S100), and writes the transferred data to the RAM 43 on the printer 30 side (S110).

When it is no longer necessary to secure a memory area on the host 20 side (S120 = YES), the host 2
A memory release command is output to 0 (S130). When the image data for one page has been developed, the printing process is executed (S140, S150).

Next, regarding the processing on the side of the print host 20,
This will be described with reference to FIG. The host 20 should output P
If there is DL data, the data is output byte by byte (S210, S220). This is exactly the same as the processing in a normal PDL printer.

In addition to this data output process, this embodiment is characterized in that when a memory reservation command is sent from the printer 30 (S230 = YES), the RAM 23 or hard disk 24 on the host 20 side is used for the printer. A memory area is secured (S240), and when the memory is secured, a response to that effect is returned (S250, S260). In addition,
If the memory allocation fails (S250 = YES),
An error is notified and the process ends (S270).

When a data write command is received from the printer 30 (S280), the save data from the printer 30 is written in the memory area reserved for the printer (S290). Then, this saved data is stored in the printer 3
When a data read command from 0 is received, it is read out,
It is output (S300, S310). The above-mentioned memory area for the printer can be released by receiving a memory release command from the printer 30 (S320, S320).
330).

According to the present embodiment, the above-described processing secures a printer memory area on the host 20 side in response to the memory shortage on the printer 30 side, and temporarily stores infrequently used data in order from the download font. Evacuate. As a result, on the printer 30 side, a sufficient ring buffer area for image data in the RAM 43 can be secured, and troubles due to insufficient memory can be avoided.

Next, the data structure of the memory reservation instruction and the like will be described. In the embodiment, the printer 30 outputs data having a structure as shown in FIGS. 4A to 4D as a memory reservation command or the like. At the beginning of each instruction, an escape code "1bh" and an identifier consisting of "M", "M", and "G" are attached (hereinafter, referred to as "memory manager identifier").

For the memory reservation instruction, "A" is added to the memory manager identifier, followed by the acronym "Allocate", and subsequently data indicating the number of bytes to be reserved is recorded. As for the memory allocation instruction, Release is added after the memory manager identifier.
"R" is added after the first letter of "," and a "memory handle" for designating the memory area to be released is recorded.

On the other hand, in the case of the data write command, "W" is attached to the memory manager identifier followed by the acronym "Write", and the "memory handle" for designating the memory area to be written is recorded. Further, after the "memory offset" indicating the write start position in the memory handle is recorded, the number of write data bytes and the data to be written are recorded.

For the data read command, "R" is added to the memory manager identifier after the initial of Read, and a "memory handle" for designating the memory area to be read is recorded. further,
After the "memory offset" indicating the read start position in the memory handle is recorded, the number of read data bytes is recorded.

On the other hand, the response from the host 20 side is shown in FIG.
It is configured as shown in (a) and (b). Here too, the memory manager identifier is added to the beginning of each of them. Then, following this, in the memory allocation completion response,
“A” of Allowable and “memory handle” indicating the secured memory area are recorded. In the data read response, the memory manager identifier, “R” of Read, the number of data bytes, and data are recorded.

In this way, in the embodiment, when a memory reservation instruction or the like is executed, a memory manager identifier is added to the beginning in order to distinguish it from normal data so as not to cause confusion. Although one embodiment of the present invention has been described above, the present invention is not limited to this embodiment. For example, print data is not limited to PDL data, and various other types are possible without departing from the scope of the invention. Of course, it can be carried out in other modes.

Regarding the distinction between the data for managing the memory and the print data, for example, IEEE128
In the case of the printing system in the ECP mode of No. 4, it is possible to distinguish by the address instead of the memory manager identifier. Specifically, from the host, the address "0
It is also possible to output the print data following "0" and the memory management data following the address "01". On the printer side, it is possible to easily distinguish between print data and memory management data by this address.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a printer system according to an embodiment.

FIG. 2 is a flowchart showing the control processing contents on the printer side in the embodiment.

FIG. 3 is a flowchart showing the contents of control processing on the host side in the embodiment.

FIG. 4 is an explanatory diagram showing a data structure of a command output from the printer side in the embodiment.

FIG. 5 is an explanatory diagram showing a data structure of a response output from the host side in the embodiment.

[Explanation of symbols]

10 ... Printer system, 15 ... Centronics cable, 20 ... Printing host 20, 21 ... C
PU, 22 ... ROM, 23 ... RAM, 24 ...
・ Hard disk, 30 ・ ・ ・ Laser printer, 35 ・
..Engine part, 40 ... Controller part, 41 ...
-CPU, 42 ... ROM, 43 ... RAM, 44
... Line scan buffer, 45 ... Input / output port.

Claims (7)

[Claims] 1. A printing method in which image data is stored in a memory on the printer side based on data sent from a host computer, and printing is executed based on the stored image data. For some of the data that should be secured,
A part of the data is saved in the memory of the host computer side as needed, and when the saved data is needed in the printer side, the data is returned to the printer side. A printing method characterized by. 2. A printing system in which image data is stored in a memory on a printer side based on data sent from a host computer, and printing is executed based on the stored image data. And the printer are connected so that they can be bidirectionally communicated with each other, and a part of the data to be secured on the printer side is saved in the memory on the host computer side as necessary. A printing system comprising: means and a data returning means for returning the data saved in the memory on the host computer side to the printer side when the printer side needs the data. 3. The printing system according to claim 2, wherein
A printing system, comprising: a memory shortage determination means for operating the data saving means when a memory shortage occurs on the printer side. 4. The printing system according to claim 2, wherein the data saving unit has a memory area on the printer side for storing a part of data to be secured on the printer side. The memory reservation command means for outputting a memory reservation command to be reserved on the computer side and the data transfer means for transferring the part of the data to the host computer side are provided, and the memory reservation command is transmitted to the host computer side. And a data storage means for storing a memory area when receiving the data and a data storage means for storing the data output by the data transfer means in the secured memory area. Is for returning the necessary data from the secured memory area to the printer side. The host computer side is provided with a return instruction means for outputting an instruction, and the host computer side is provided with a data retransfer means for reading out the corresponding data from the memory area and transferring it to the printer side when the return instruction is received. A printing system comprising the above. 5. The printing system according to claim 4, wherein the printer side is provided with a memory release command output means for outputting a memory release command for releasing a memory area secured by the host computer side, the host computer The printing system is characterized in that the side is provided with a memory releasing means for releasing the reserved memory area when the memory releasing instruction is received. 6. The printing system according to claim 2, wherein the printer is a page printer having a page memory, and the saved data is secured in a storage area other than the page memory on the printer side. A printing system characterized by being data to be stored. 7. The printing system according to claim 6, further comprising, when there are a plurality of types of data to be saved, a save priority order determining unit that sets a save priority order according to the type of data. .