JP2001014116A - Printer control circuit, printer and print system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the processing load of a host device and to accelerate a printing speed in a print system in which the host device transfers RGB data to a printer. SOLUTION: An intermediate hardware 4 provided with a source image data format conversion circuit 5 for converting the data format of RGB source image data 10 depending on the kind of an OS is connected between a host computer 1 and a printer 3. The printer driver 11 of the host computer 1 transmits a format parameter for specifying the format depending on the OS to the format conversion circuit 5 of the intermediate hardware 4 together with the RGB source image data 10. The format conversion circuit 5 converts the RGB source image data 10 depending on the OS to the image data 53 of a common format processable by the printer 3 based on the format parameter. A color conversion/half toning circuit 6 fetches the image data 53, performs a color conversion processing and a half toning processing to the image data 53, turning them to printer commands 55 processable by the printer 3 and sends them to the printer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer control technique for high-speed printing.

[0002]

2. Description of the Related Art In a printing system, original image data in a host computer is represented by host-side color system data, typically RGB data, which does not always match printer-side color system data (typically, CMYK data). is there. This RGB data is Microsoft Windows 9
8 and the format of each OS such as Apple Computer's Macintosh is different. In other words, the format of the RGB data depends on each OS.

[0003]

A process for printing out the original image data in the host computer;
That is, color conversion processing for converting RGB data to CMYK data and halftoning processing for binarizing the CMYK data are performed by a printer driver in the host computer.
Alternatively, it is performed by a printer (strictly, imaging software in the printer).

When processing such as color conversion and halftoning is performed on the printer side, a printer driver of a host computer receives original image data, that is, RGB data from the OS of the host computer and transfers it to the printer. Since the printer driver does not perform color conversion or halftoning processing, the load on the CPU of the host computer is lightened accordingly. However, the printer driver
Since the RGB data is in a format that depends on the OS, the format must be converted to a format that the printer on the receiving side can understand and perform the above conversion process.

[0005] The format conversion of the RGB data is as follows.
There is a considerable burden on the CPU of the host computer. As a result, there is a problem that the opening of the host device is delayed and the printing speed is reduced.

Accordingly, it is an object of the present invention to provide a host
In a printing system that transfers GB data to a printer without performing color conversion or halftoning, it is an object of the present invention to reduce a processing load on a host device and increase a printing speed.

[0007]

According to the present invention, a printer control circuit is provided between a host device and a printer. This printer control circuit may be built in the host device, may be built in the printer, or may be external to both. The printer control circuit includes a receiving unit, a format conversion unit, and an image data transfer unit. The receiving unit receives, from the host device, original image raster data whose data format depends on the OS in the host device, and format parameters specifying an OS-dependent format of the original image raster data.
The format conversion means converts the original image raster data in the OS-dependent format into image data in a predetermined common format according to the received format parameters.
The image data transfer unit converts the image data in the common format into image data in a format that can be processed by the printer and transfers the image data to the printer.

According to the present invention, since the printer control circuit performs the format conversion process, the host device does not need to perform the format conversion process, so that the load on the CPU of the host device can be reduced and high-speed printing can be performed. Become.

[0009] In a preferred embodiment, the printer control circuit is a pure hardware circuit. As a result, the printer control circuit becomes an ASIC (Application Specified IC).
For example, it can be made cheaper than a conventional high-speed printing system equipped with a high-speed CPU.

In a preferred embodiment, the format conversion means has a rearrangement means for rearranging a byte array constituting one pixel data of the original image raster data in a byte order according to a common format based on the format parameter.

[0011] In a preferred embodiment, the format conversion means is arranged such that the number of bytes constituting one pixel data of the original image raster data is smaller than the number of bytes constituting one pixel data of the common format, and the one pixel data of the common format is empty. When a byte is generated, a mask processing means for automatically filling empty bytes with null data is provided.

For example, if one pixel data of the original format raster data of the OS-dependent format is three bytes while one pixel data of the common format is four bytes, one byte of free bytes is generated. . Therefore,
The format conversion means automatically creates null data for the one-byte empty byte and performs a masking process with the null data. Since the creation of null data can be performed in parallel with the format conversion processing, it is possible to prevent the printing speed from deteriorating.

In a preferred embodiment, the printer control circuit further includes a circuit for performing color conversion processing and halftoning processing on the image data in the common format, and converts the image data after performing the color conversion processing and halftoning processing. Transfer to printer.

[0014]

FIG. 1 shows an overall configuration of a printing system according to an embodiment of the present invention.

In the printing system shown in FIG. 1, original image data (that is, RGB
The conversion of the data into the final CMYK data is performed by the intermediate hardware 4 provided between the host computer 1 and the printer 3. That is, the intermediate hardware 4 is pure hardware made of an ASIC (Application Specified IC) or the like, and converts the RGB raster data sent from the host computer 1 into a CMYK system (or a CMY system) using a lookup table or the like. ), And converts color-converted CMYK raster data into, for example, 256-tone pixel values of each color by using a method such as error diffusion or dithering to avoid hitting or hitting each color dot of CMYK. "Half-toning" for converting the pixel value into a two-stage pixel value indicating the above is performed. Further, when the printer 3 is, for example, an ink jet printer or an impact wire dot printer, in order to improve image quality, dots are printed in an order different from the arrangement order of pixel positions, that is, so-called “interlaced” printing or “overprinting”. Processing for performing "lap" printing is also performed.

Original image data (RGB) received from the host computer 1 by the intermediate hardware 4 for performing the above-described processing.
Data) is bitmap expanded image data,
That is, it is raster image data and has a format dependent on the OS 7 of the host computer 1. The intermediate hardware 4 includes a format conversion circuit 5 for converting RGB raster image data having a format dependent on the OS 7 from the host computer into a predetermined common format, and the above-described color conversion and conversion for the RGB data in the common format. A color conversion / halftoning circuit 6 for performing a halftoning process. As described above, the format conversion circuit 5 and the color conversion / halftoning circuit 6
It is a hardware logic circuit such as C, which is not a computer that executes software by a CPU, and thus can perform high-speed processing.

In the host computer 1, the printer driver 11 receives the image data 9 created by the application software from the OS 7, and if the image data 9 is represented by a graphic function or a character code, the raster data is "rasterized". The raster image data 10 is created by developing the map. This raster image data 10
Is typically an RGB full-color format, that is, an 8-bit word in which one color component per pixel can represent 256 gradations in the RGB color system.
Other formats, for example, RGB binary, monochrome 256 gradation, monochrome binary, etc., are also possible. In the following description, the raster image data 10 is assumed to be RGB full-color data, and is hereinafter referred to as RGB original image data 10. This R
The data format of the GB original image data 10 is OS7
It depends on the type. For example, as shown below.

(1) Format of “first OS”: <
R, G, B><R, G, B> ... Here, <> means data for one pixel. In this format, data for one pixel is composed of three bytes arranged in the order of R, G, and B.

(2) Format of "second OS": <
R, G, B, x><R, G, B, x> ... That is, data for one pixel is composed of 4 bytes arranged in the order of R, G, B, x. Here, “x” is a byte indicating the attribute of the image.

(3) Format of "third OS": <
B, G, R><B, G, R> ... That is, data for one pixel is composed of three bytes arranged in the order of B, G, and R.

(4) Format of "fourth OS": <
x, R, G, B><x, R, G, B> ... That is, data for one pixel is composed of 4 bytes arranged in the order of x, R, G, B.

The printer driver 11 converts the RGB original image data 10 having a format dependent on the OS 7 into an intermediate command 13 having a predetermined command format that can be understood by the intermediate hardware 4, and converts it into the intermediate command 13 via the OS 7. Send to intermediate hardware 4.

The intermediate hardware 4 is connected between the host computer 1 and the printer 3. The format conversion circuit 5 of the intermediate hardware 4 receives the intermediate command 13 from the host computer 1, refers to the format parameter included in the intermediate command 13, and according to the RGB,
The OS7-dependent data format of the original image data 10 is changed to a common format (for example, <x, R, G, B><
x, R, G, B>...), and sends it to the color conversion / halftoning circuit 6. Color conversion
The half-toning circuit 6 uses the common format R
The GB data 53 is color-converted into CMYK data, which is further half-toned to be converted into CMYK binary data, which is sent to the printer 3 as a printer command 55 that the printer 3 can understand.

Hereinafter, a more specific description will be given.

The printer driver 11 uses the RGB original image data 10 to create an intermediate command 13 having a configuration as shown in FIG.

FIG. 2 shows the structure of the intermediate command 13 output from the printer driver 11.

As shown in FIG. 2, the intermediate command 13 is
It comprises a command name field 15, a format parameter field 17, and an original image data field 19 in which the RGB original image data 10 is set.

In the command name field 15, a command name indicating the intermediate command 13, for example, <xfe
rJ> is set.

In the format parameter field 17, a format parameter (hereinafter, f parameter) indicating the format of the RGB original image data 10 set in the RGB original image data field 19 is set. The f-parameter is, for example, an 8-bit word as shown in FIG. One bit is
For example, empty data). "Valid bytes" parameter 21
Indicates how many bytes of valid data for one pixel are composed of the RGB original image data 10.
If "11", 4 bytes are valid (that is, one pixel is composed of 4 bytes). If "10", 3 bytes are valid (that is, 1 byte).
(A pixel is composed of 3 bytes). The "byte order" parameter 23 indicates the arrangement order of the R, G, and B components in the number of effective bytes of the RGB original image data 10. "0000" indicates "B, G, R", and "01110" indicates "R, G, R". G, B, x "or" R, G, B "," 1011
"1" indicates that they are arranged in "x, R, G, B".
Specifically, parameters are set for the first to fourth OSs as described below.

(1) Format of “first OS”: <R, G, B>
<R, G, B> ... → “10” “01110” (2) Format of “second OS”: <R, G, B,
x><R, G, B, x>... → “11” “01110” (3) Format of “third OS”: <B, G, R>
<B, G, R>... → “10” “00000” (4) Format of “fourth OS”: <x, R, G,
B><x, R, G, B>... → “11” “10111”.

FIG. 4 shows the configuration of the intermediate hardware 4.

The format conversion circuit 5 of the intermediate hardware 4 includes a command interpretation circuit 25, an input register 27, a position counter 29, a write byte position decoder 31, a byte write circuit 33, a mask data generation circuit 35, and a byte position mask processing circuit 37. , An output register 39.
First, the command interpretation circuit 25 receives the intermediate command 13 from the printer driver 11.

When the command interpreting circuit 25 recognizes that the command is the intermediate command 13 from the command name, the “valid byte number” parameter 21 and the “byte order” parameter 23 of the f parameter 17 included in the command 13 are described.
Is written into the input register 27, and the RGB original image data 10
To the byte write circuit 33. The input register 27 has at least a storage area 41 for the “valid byte count” parameter 21 and a “byte order” parameter 23.
Storage area 43 is secured. The RGB original image data 10 is transferred to the OS 7 by the byte write circuit 33.
The data is output to the corresponding byte plane of the 4 bytes according to the arrangement order of each color data in the dependent format. For example, if the RGB original image data 10 is configured in the format <R, G, B> that depends on the “first OS”, the data is input in the order of “R” → “G” → “B”. , "Second OS" dependent format <
x, R, G, B>, “x” → “R”
→ “G” → “B” are input in this order.

The byte position counter 29 counts each time the byte write circuit 33 reads out the color data, and resets the counted number to the same value as the number of valid bytes recorded in the input register 27. To go. For example, if the number of valid bytes is 4 bytes,
Reset is performed every time counting is performed four times, such as "0, 1, 2, 3, (reset) 0, 1, 2, 3, (reset) 0, ...". If the number of valid bytes is 3 bytes, "0,
1, 2, (reset) 0, 1, 2, (reset) 0,
... ”, Reset every time it counts three times. The byte position counter 29 counts in this manner, and each time the above-described color data is read, the count result (that is, the byte position of each color data in the RGB original image data 10) 45 is written to the write byte position decoder 31. Notify.

The write byte position decoder 31 receives the count result 45 from the byte position counter 29, and receives the count result 45 and the "byte order" stored in the input register 27.
The byte order shown in the parameter 23 is referred to. Then, based on this, the common format 4
For each byte data, it is determined to which byte position the above-mentioned read color data is to be written, and the determined write byte position 47 is instructed to the byte write circuit 33.

The byte write circuit 33 includes the input register 2
7, each color data of the RGB original image data 10 is read out (that is, read out one byte at a time), and each is written to a predetermined byte position of the common format data in accordance with the instruction of the write byte position decoder 31. This will be specifically described with reference to FIG.
Here, the common format is <x, R, G, B>
And

RG coming through the command interpreting circuit 35
If the format of the B original image data 10 depends on, for example, the “first OS” (that is, <R,
G, B><R, G, B>...), As shown in FIG.
Byte write circuit 33 in the order of “R” → “G” → “B”
Comes entered. According to the instruction of the write byte position decoder 31, the byte write circuit 33 outputs the first "R"
Is written in the second byte of the register 48, the second "G" is written in the third byte, and the third "B" is written in the fourth byte. If it depends on the “second OS”,
As shown in (B), each data is read out in the order of “R” → “G” → “B” → “x”, and the first “R” is stored in the second byte according to the above instruction. "G" is written in the third byte, the third "B" is written in the fourth byte, and the fourth "x" is written in the first byte. If it depends on the “third OS”, as shown in FIG. 5C, “B” →
Each data is read in the order of “G” → “R”, and the first “B” is in the fourth byte, the second “G” is in the third byte, and the third “R” is in accordance with the above instruction. Write each in the second byte. If it depends on the “fourth OS”, as shown in FIG. 5D, “x” → “R” → “G”
→ Read each data in the order of “B”, and follow the above instructions, with the first “x” in the first byte, the second “R” in the second byte, and the third “G” in the third byte. Then, the fourth “B” is written in the fourth byte.

The byte writing circuit 33 reads out valid data for one pixel in the RGB original image data 10 and, when the byte writing is completed, transfers the written data 49 to the byte position mask processing circuit 37.

In the writing of one pixel of valid data (each color data) described with reference to FIG. 5, if the valid data is 3 bytes (that is, the “valid number of bytes” is 3 bytes), 1 byte of the register 48 Nothing is written to the eye, so it is the value originally written there. Therefore, in order to make the first byte null data, the mask data generation circuit 35 and the byte position mask processing circuit 37 perform a mask process on the first byte.

That is, the mask data generation circuit 35
"Valid number of bytes" parameter 21 from input register 27
Then, the “byte order” parameter 23 is read out, and mask data 51 of 4 bytes corresponding to the number of bytes of the post-write data 49 is generated with reference to each of them. That is, when the “valid number of bytes” is 3 bytes, a mask in which all bits of the first byte are 0 and all bits of the other 3 bytes are 1 in order to make the first byte of the 4 bytes null data. The data 51 is generated. "Valid bytes" is 4
In the case of a byte, the mask data 51 in which all the bits of the 4-byte are 1 is generated so as not to mask any byte. The mask data generation circuit 35 passes the generated mask data 51 to the byte position mask processing circuit 37.

The byte position mask processing circuit 33 receives the post-write data 49 from the byte write circuit 33 and the mask data 51 from the mask data generation circuit 35, and performs an AND operation on the post-write data 49 and the mask data 51.
D operation, and outputs the AND operation result 53 to an output register 39
Write to. Specifically, when the “valid number of bytes” is 3 bytes as described above, the first byte of the 4 bytes is “0, 0, 0, .., And the other three bytes are set to “1, 1, 1,...”. By performing an AND operation on the post-write data 49 and the mask data 51, the operation result data 53 becomes , The first byte “x” is null data of “0, 0, 0,...”, And the other three bytes “R, G, B” are “R, G, B” of the post-write data 49.
G, B ". When the “valid number of bytes” is 4 bytes, the data 53 after the mask processing is exactly the same as the post-write data 49. The byte position mask processing circuit 37 writes the RGB data 53 after the mask processing into a predetermined address of the output register 39.

The above RGB written in the output register 39
The data 53 is taken into the color conversion / halftoning circuit 6.

According to such an embodiment, the host computer 1 (printer driver 11) does not need to perform format conversion of the RGB original image data 10 at all.
This format conversion is performed by a dedicated hardware circuit (that is, the format conversion circuit 5 of the intermediate hardware 4).
Do. The host computer 1 only needs to specify the format type of the RGB original image data 10 to the intermediate hardware 4. Therefore, C of the host computer 1
The load on the PU is considerably reduced as compared with the related art, so that high-speed printing can be performed without delaying opening of the host device. Also, the host computer 1
Can set the "byte order" parameter arbitrarily, so that even if the OS 7 is of any type, or if the format of the image data 10 requested by the OS 7 changes, It is possible to cope by changing the setting of "byte order". In addition, the host computer 1 can set the “valid number of bytes” parameter according to the format relating to the color system and the number of gradations of the original image data 10, which also contributes to high-speed printing as described below. I do.

For example, when the color system of the original image data 10 is monochrome, the host computer 1 sends RG
Since only the “G” data of the B data is continuously transmitted, the host computer 1 sets the “valid byte number” parameter 21 to “1 byte valid”. This allows
Whenever the 1-byte "G" data is received, the format conversion circuit 5 writes it into the designated byte position, and automatically generates mask data including 3-byte null data that becomes an empty byte in parallel. Then, a mask process is performed. As described above, since the null data is generated in parallel with the writing of the color data, printing can be performed at high speed without deteriorating the printing speed.

Also, since the intermediate hardware 4 can be created by an ASIC or the like, it is less expensive than a conventional high-speed printing system equipped with a high-speed CPU.

The arrangement of the intermediate hardware 4 has three variations as shown in FIG.
That is, a system built in the host computer 31 as shown in a block 10 in FIG. 6, a system built in the printer 9 as shown in a block 30, and an external connection to the host computer 31 and the printer 9 as shown in a block 20. It is a method. In the built-in host type, the format conversion circuit 5 is provided in the form of an option board for a host computer, is connected to an internal bus of the host computer 31, and is connected to the printer 9 by a parallel interface cable (or a communication network), for example. Can be connected. This has the advantage that it can handle a plurality of printers. On the other hand, in the printer built-in type, the format conversion circuit 5 is provided in the form of an option board for a printer, connected to the internal bus of the printer 9,
The host computer 31 can be connected with, for example, a parallel interface cable (or a communication network). This has the advantage of being able to handle multiple hosts. In the external type, the format conversion circuit 5
Can be connected to both the host computer 31 and the printer 9 by, for example, a parallel interface cable (or a communication network).

Although some preferred embodiments of the present invention have been described above, these are merely examples for describing the present invention, and are not intended to limit the scope of the present invention only to these examples. . The present invention can be implemented in other various forms. For example, some of the functions of the intermediate hardware 4 may be implemented in software by a CPU for the intermediate hardware 4.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the overall configuration of a print system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of an intermediate command 13;

FIG. 3 is a block diagram showing a configuration of a format parameter field 17;

FIG. 4 is a block diagram showing a configuration of intermediate hardware 4.

FIG. 5 is a view for explaining a method of byte writing of each color data of the RGB original image data 10 depending on first to fourth OSs.

FIG. 6 is a diagram showing a variation in arrangement of an original image data format conversion circuit 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host computer 3 Printer 4 Intermediate hardware 5 Original image data format conversion circuit 6 Color conversion / halftoning circuit 7 OS 11 Printer driver 25 Command interpretation circuit 27 Input register 29 Byte position counter 31 Write byte position decoder 33 Byte write circuit 35 Mask Data generation circuit 37 Byte position mask processing circuit 39 Output register

Claims (11)

[Claims] 1. A printer control circuit connected between a host device and a printer, comprising: original image raster data whose data format depends on an OS in the host device;
Receiving means for receiving a format parameter designating an S-dependent format from the host device; format converting means for converting the original image raster data of the OS-dependent format into image data of a predetermined common format according to the format parameter; A printer control circuit comprising: image data transfer means for converting the image data in the common format into image data in a format that can be processed by the printer and transferring the image data to the printer. 2. The method according to claim 1, which is a pure hardware circuit.
Printer control circuit as described. 3. The format conversion unit has a rearrangement unit that rearranges a byte array forming one pixel data of the original image raster data into a byte order according to the common format based on the format parameter. Item 2. The printer control circuit according to Item 1. 4. The format conversion means, wherein the number of bytes constituting one pixel data of the original image raster data is smaller than the number of bytes constituting one pixel data of the common format, and is free for one pixel data of the common format. 2. The printer control circuit according to claim 1, further comprising mask processing means for automatically filling the empty bytes with null data when a byte is generated. 5. A printer according to claim 1, further comprising a circuit for performing a color conversion process and a halftoning process on the image data in the common format, and transferring the image data after the color conversion process and the halftoning process to the printer. Item 2. The printer control circuit according to Item 1. 6. A printer comprising the printer control circuit according to claim 1. 7. A host device comprising the printer control circuit according to claim 1. 8. A host device, a printer, and a printer control circuit connected to the host device and the printer, wherein the host device has an OS-dependent format dependent on an OS in the host device. Original image raster data generating means for generating image raster data, format parameter generating means for generating a format parameter for specifying an OS-dependent format of the original image raster data, original format raster data in the format parameter and the OS-dependent format Transmitting means for transmitting the original image raster data of the OS-dependent format and the format parameter from the host device; and According to the previous parameters Format conversion means for converting the original image raster data of the OS-dependent format into image data of a predetermined common format; and image data for converting the image data of the common format into image data of a format that can be processed by the printer and transferring the image data to the printer A print system comprising a transfer unit. 9. The printing system according to claim 8, wherein said printer control circuit is a pure hardware circuit. 10. The printer control circuit further includes a circuit for performing a color conversion process and a halftoning process on the image data in the common format, and converts the image data after performing the color conversion process and the halftoning process. 9. The print system according to claim 8, wherein the data is transferred to the printer. 11. An original image raster data creating step for creating original image raster data having an OS-dependent format dependent on an OS in a host device, and a format parameter for specifying an OS-dependent format of the original image raster data is generated. A computer-readable recording medium recording a program for causing a computer to execute a format parameter generating step of performing the following, and a transmitting step of transmitting the format parameters and the original image raster data of the OS-dependent format to a predetermined external device. .