JP2002264423A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer in which printing subjected to clipping can be executed efficiently. SOLUTION: The printer is arranged such that the compressed raster data (e.g. 'first compressed C raster data') of each color component concerning to each raster of image data generated based on print data is stored in a compressed raster data storage area 201 upon receiving the print data, information (raster offset, number of raster bytes) concerning to the storage location and size of each compressed raster data is stored in an address table 2021 , and only compressed raster data required for printing is decompressed based on the information before being fed to a print engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a printing apparatus for executing a printing process including a compression / expansion process.

[0002]

2. Description of the Related Art As is well known, it is necessary to prepare one page of image data in order to cause a print engine provided in a printing apparatus generally called a printing apparatus to perform printing. It is. The size of this image data is
When the resolution is high or the number of gradations is large, it becomes extremely large. If a memory capable of storing such image data is provided, the price of the printing apparatus becomes high. Therefore, one page of image data is prepared in a compressed state on the memory, and the image data is decompressed. While supplying the print engine.

[0003]

SUMMARY OF THE INVENTION
In a conventional printing apparatus in which a printing process including a decompression process is executed, a plurality of pieces of compressed data from which band-size image data is obtained are created at the time of printing.

For this reason, in a conventional printing apparatus, when clipping is performed on the printing apparatus side, useless data must be expanded. Also, as is well known, when performing double-sided printing, it is sometimes necessary to perform reverse printing in which the image is reversed (rotated 180 degrees) on one side. However, it is necessary to decompress the compressed data and then reverse the image. Therefore, the conventional printing apparatus is configured to perform processing for inverting an image before compression. For this reason, a conventional printing apparatus is an apparatus that performs reverse printing even when it is better not to perform reverse printing due to some abnormality. In addition, since a function of compressing an image after inverting the image has to be provided, there is a problem that the configuration (contents of a program) of the printing apparatus is complicated.

The present invention has been made in view of such circumstances, and a first object of the present invention is to provide a printing apparatus capable of efficiently performing clipped printing.

A second object of the present invention is to provide a printing apparatus capable of high-speed reverse printing, in which an image is inverted when decompressing compressed data.

[0007]

In order to solve the above-mentioned first problem, a printing apparatus according to a first aspect of the present invention supplies a plurality of raster data, each of which defines one line of drawing content. A print execution unit for forming an image corresponding to a plurality of supplied raster data on a sheet, a first storage unit, a second storage unit, and a plurality of ordered raster data representing an image to be processed; , Compressed raster data generated by compressing the raster data is generated, the generated plurality of compressed raster data is stored in the first storage means, and the storage position of each compressed raster data in the first storage means is indicated. Compression processing means for storing information in the second storage means; and information to be processed from a plurality of compressed raster data stored in the first storage means with reference to the information stored in the second storage means. Together sequentially read some compressed raster data relating to the portion that is specified to print the image according to the order, and a decompression means having a function of supplying to the print execution means to decompress each compressed raster data read out.

In other words, the printing apparatus according to the first aspect of the present invention generates compressed data (a set of compressed raster data) in a form capable of decompressing only data relating to an arbitrary raster, based on the compressed data. In this case, only the data relating to the raster required for printing is expanded and printing is performed. Therefore, according to the printing apparatus of the first aspect, the clipped printing can be efficiently performed. Further, if the configuration of the printing apparatus according to the first aspect is adopted, it is possible to manufacture a printing apparatus that completes printing at a high speed, and to perform compression processing and decompression processing realized by relatively low-performance hardware. In spite of the provision of the means, it is possible to manufacture a printing apparatus that performs printing in a form in which the function of the print execution means is sufficiently exhibited.

[0009] The printing apparatus according to the first aspect of the present invention comprises:
This may be realized by mounting two memories functioning as a first storage unit and a second storage unit, and may be realized by mounting one memory functioning as a first storage unit and a second storage unit. May be. Further, the printing apparatus according to the first aspect of the present invention may be realized as an apparatus that receives print data from a host computer and performs printing, and that performs printing in accordance with scanned image data (ie, a copy apparatus). Machine).

When the printing apparatus according to the first aspect of the present invention is realized, the decompression processing means refers to the information stored in the second storage means and is stored in the first storage means. A plurality of compressed raster data are sequentially read out in the reverse order, and for each read compressed raster data, after the compressed raster data is expanded, the arrangement order of the pixel data constituting the raster data obtained by the expansion is changed. Means that also has a reversal / expansion function that generates inverted data and supplies the data to the print execution means may be employed. Further, as expansion processing means, some of the plurality of pieces of compressed raster data stored in the first storage means relating to a portion for which printing of an image to be processed is designated for printing is performed in the reverse order. After sequentially reading the compressed raster data, the compressed raster data is decompressed, and then the data in which the arrangement order of the pixel data constituting the raster data obtained by decompression is reversed is generated and supplied to the print execution means. Alternatively, means having an inversion / expansion function may be employed.

Regardless of which decompression means is employed, the printing apparatus according to the first aspect of the present invention can solve the second problem by reversing an image when decompressing compressed data, that is, the second problem. It can be a device. Because as long as the raster data can be obtained in reverse order,
This is because generating data representing an inverted image at high speed is a simple matter (it can be realized by processing that does not take much time). In addition, if the latter one of the two types of decompression processing means is adopted, the printing apparatus of the first aspect is a device capable of performing reverse printing of an arbitrary portion of the processing target image. Can be done.

Further, in order to solve the second problem,
The printing apparatus according to the second aspect of the present invention receives supply of a plurality of raster data defining drawing contents for one line, and forms an image on a sheet according to the plurality of supplied raster data. A print execution unit, a first storage unit, and a second storage unit.
Storage means for generating compressed raster data obtained by compressing the raster data for each of a plurality of ordered raster data representing an image to be processed, storing the generated plurality of compressed raster data in the first storage means; ,
Compression processing means for storing information indicating the storage position of each compressed raster data in the first storage means in the second storage means;
With reference to the information stored in the storage means, the plurality of compressed raster data stored in the first storage means are sequentially read out in an order reverse to the order. And decompression processing means having a function of generating data obtained by reversing the arrangement order of pixel data constituting raster data obtained by decompression and supplying the generated data to the print execution means.

In other words, the printing apparatus according to the second aspect of the present invention generates compressed data (a set of compressed raster data) in a form capable of decompressing only data relating to an arbitrary raster, based on the compressed data. , A configuration in which reverse printing is performed. As long as raster data can be obtained in reverse order, it is easy to generate data representing an inverted image, so if this configuration is adopted, reverse printing can be performed for some unexpected reason. When it is better not to perform the printing, it is possible to realize a printing apparatus that performs normal printing. Further, since it is not necessary to provide the printing apparatus with a function of generating image data of an inverted image and then compressing the image data, the configuration of the printing apparatus can be simplified.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a schematic configuration of a printing apparatus 10 according to an embodiment of the present invention. First, an outline of the printing apparatus 10 according to the embodiment will be described with reference to FIG.

A printing apparatus 10 according to one embodiment of the present invention.
Includes a control unit 11 and a printing mechanism unit 12 as illustrated. The print mechanism unit 12 includes a print engine 13 that operates upon receiving supply of print image data including four types of image data related to C, M, Y, and K planes, a paper feed device, a paper discharge device, and a duplex printing device. This unit includes a paper reversing mechanism and the like.

The control unit 11 is a unit that generates print image data based on the received print data and supplies the print image data to the print engine 13. The control unit 11 includes a host interface unit 15 that receives print data transmitted from the host computer 50, a ROM 16 in which various programs and font data are stored, a CPU 17 that operates according to the programs stored in the ROM 16, A memory 20 for storing compressed data and the like, a color conversion processing unit 18 and a compression processing unit 19 used when generating compressed data of printing image data, and generating printing image data from compressed data of printing image data. It is composed of a decompression processing unit 21 and the like that are used when performing. Each of the color conversion processing unit 18, the compression processing unit 19, and the decompression processing unit 21 is a so-called ASIC (application specific IC).

Hereinafter, the operation of the printing apparatus 10 when receiving print data will be described focusing on the operation of the compression processing unit 19 and the decompression processing unit 21.

The print data is transferred to the host interface unit 15
Under the control of the CPU 17, the printing device 10 generates RGB image data corresponding to the print data in the memory 20, and converts the RGB image data into a CMYK image using the color conversion processing unit 18 under the control of the CPU 17. A compressed data generation process is performed which converts the data into data and supplies the data to the compression processing unit 19.

The compression processing section 19 that is used when the compressed data generation process, as schematically shown in FIG. 2, comprises four compression circuits 191 _{1 to 191 4.}

The compression circuit 191 _X (X = 1 to 4) takes in data of a specific color component included in the CMYK image data supplied from the color conversion processing unit 18 and raster data (one line for the specific color component) (Compressed raster data)
Are sequentially stored in the compressed data storage area 201 set on the memory 20.

Further, a compression circuit 191 _X (X = 1 to 4)
Each time the compressed raster data is stored in the compressed data storage area 201, the storage start position of the compressed raster data is
A raster offset indicated by an offset from the start address of the compressed data storage area 201 (hereinafter referred to as a compressed data start address) and a raster byte number indicating the size (byte number) of the compressed raster data are stored in the memory 20.
A process for storing in the address table 202 _X set above is also performed.

[0023] The compression circuit 191 _{1 to 191 4} is configured to store compressed raster data to the compressed data storage area 201 in a round robin fashion. That is,
In the compressed data storage area 201, as schematically shown in FIG. 3, compressed raster data (C1, M1, M1, and Y1 in FIG. 3) relating to the C, M, Y, and K components of the first raster.
1 "," K1 ") are present at the beginning, followed by compressed raster data for the C, M, Y, and K components of each of the second and subsequent rasters. Compressed raster data is stored.

The raster offset and the number of raster bytes are fixed-length data.
_X, as shown schematically in FIG. 4, the number of rasters offset and raster byte, so that they are arranged without gaps alternately stored in the address table 202 _X.

When the generation of the compressed raster data for one page is completed, in principle, (print engine 1
3 is in an operable state and there is no need to wait for the generation of the compressed raster data for the next page), while the expansion processing unit 21 is used under the control of the CPU 17,
A print image data generation process, which is a process in which print image data is generated from a plurality of pieces of compressed raster data in the compressed data storage area 201 and supplied to the print engine 13, is performed.

As shown in FIG. 5, the decompression processing unit 21 used in the print image data generation processing includes a DMA circuit 211, a decompression circuit 212, a left and right clip circuit 213, and a left and right inversion circuit 214.

At the time of print image data generation processing, the decompression processing unit 21 stores the compressed data start address, which is the start address of the compressed data storage area 201, and left and right clip position designation data for designating the left and right clip positions. Is given. The decompression processing unit 21 also includes the number of read rasters for specifying the number of rasters to be drawn by the print engine 13 and the reversal adoption data for specifying whether or not to invert the image (rotate 180 degrees). A read start address for specifying a raster to be printed by an address at which a raster offset for compressed raster data relating to the raster is stored is given. Details will be described later,
The processing executed by the decompression processing unit 21 based on these data (hereinafter, referred to as control information) is processing for supplying image data for one plane to the print engine 13. , Expansion processing unit 21
Is performed four times.

Specifically, the raster numbers are N _{S to} N _E (N _S
When printing is performed without inversion using only raster data in the range of <N _E ), first, the decompression processing unit 21
Compressed data start address, with including lateral clip-position specifying data, reading raster number, inverted adoption data, the read start address, _{respectively, "N E -N S +1"} , data indicating that not performed inversion, the address table 202
Control _{information 1} of the first N _S raster offset is the address stored is given. Thereafter, every time the feed to the print engine 13 of the image data of one plane is completed, the expansion processing section 21, instead of the address of the read start address first N _S raster offset address table 202 ₂ is stored control information, address control information the read start address first N _S raster offset address table ₂₀₂₃ is changed to the address stored, the N _S raster offset address table 202 ₄ read start address is stored Is given.

On the other hand, when performing printing and reversed, the expansion processing section 21, first, inversion adoption data are data indicating that perform inversion, the read start address is an address table 202 ₁ of the first N _E Control information, which is an address at which the raster offset is stored, is provided. Thereafter, the control information of the read start address first N _E raster offset address table 202 ₂ is changed to the address stored, the address table 20 to read start address
Control information first N _E raster offset of 2 ₃ is changed to the address stored, the control information of the read start address first N _E raster offset address table 202 ₄ is changed to the address stored is given.

As shown in the figure, the decompression processing unit 2
1 is supplied to the left and right clipping circuit 213, and the inverted adoption / non-adoption data is supplied to the DMA circuit 211 and the left and right inverting circuit 214. The compressed data start address, the number of read rasters, and the read start address are supplied to the DMA circuit 211.

The DMA circuit 211 is a circuit that performs the following operation when a compressed data start address, the number of read rasters, a read start address, and inverted adoption data are given.

The DMA circuit 211 stores the read start address as a raster offset read address, and stores two data of a predetermined size stored in the memory 20 from the raster offset read address, that is, two data of a predetermined size.
The raster offset and the number of raster bytes stored in one of the address tables 202 _X (X = 1 to 4) are read. Then, an address obtained by adding the read raster offset to the head address of the compressed data is obtained, and data of a size equal to the number of read raster bytes stored in the memory 20 from the obtained address, that is, compressed data storage Certain compressed raster data stored in the area 201 is read and supplied to the decompression circuit 212.

Thereafter, the DMA circuit 211 increments or decrements the raster offset read address by a predetermined amount (the total size of the raster offset and the number of raster bytes) in accordance with the inverted adoption data. Then, the above-described processing is executed again for the changed raster offset read address.

Then, the DMA circuit 211 ends the processing when the supply of the compressed raster data of the same number as the read raster number to the decompression circuit 212 is completed.

That is, the DMA circuit 211 uses the combination of the read start address, the read raster number, and the inverted adoption data as shown in FIGS. 6A and 6B.
Compressed raster data for a total of (Q−P + 1) rasters from the Pth raster to the Qth raster is supplied to the decompression circuit 212 in ascending order of raster numbers.
As schematically shown in (B), a circuit that can supply compressed raster data for a total of (Q-P + 1) rasters from the Qth raster to the Pth raster to the decompression circuit 212 in descending order of raster number. It has become.

The expansion circuit 212 to which the compressed raster data is supplied is a circuit that can expand the compressed raster data. The DMA circuit 21 described above
1 is a process of reading the raster offset and the number of raster bytes from the address table 202 _X and a process of reading the compressed raster data from the compressed data storage area 201 and supplying the same to the decompression circuit 212. The speed and timing are such that the speed is higher than the speed at which raster data is to be supplied to the print engine 13.

A left and right clip circuit 213 to which the left and right clip position designation data is supplied removes the amount of pixel data corresponding to the left and right clip position designation data from the left and right sides of the raster data output from the expansion circuit 212. It has become.

The left / right inversion circuit 214 to which the inverted adoption / rejection data is supplied is supplied with the left / right clipping circuit 21 when the inverted adoption / rejection data indicating that no inversion is performed is supplied.
The raster data supplied from 3 is directly used (however,
The buffering for timing adjustment is performed.) When the reverse adoption data indicating the reversal is supplied to the print engine 13 and instructing the reversal, the left and right of the raster data supplied from the left and right clipping circuit 213 is reversed. The circuit supplies the print engine 13 later. That is, when inversion adoption data indicating inversion is supplied, the left / right inversion circuit 214 temporarily stores the raster data supplied from the left / right clipping circuit 213, and arranges the pixel data based on the raster data. Generate raster data in reverse order and print engine 1
Supply 3

As described above, the printing apparatus 10 according to the embodiment generates compressed data (a set of compressed raster data) in a form capable of decompressing only data relating to an arbitrary raster, and generates the compressed data. , Only the compressed raster data relating to the raster required for printing is decompressed and supplied to the print engine 13. In other words, the printing apparatus 10
This apparatus performs clipped printing without performing useless processing (processing for expanding unused data).

As described with reference to FIG. 3, the printing apparatus 10 according to the embodiment is an apparatus in which compressed raster data for each color component is stored in the memory 20 without any gap. Therefore, as schematically shown in FIG.
Effective use of the memory 20 can be achieved as compared with a case where a storage area for each color component is secured on the memory 20.
Further, when the compressed raster data is stored in the form shown in FIG. 8, after that, a process of collecting these data in one place is actually required. Therefore, the printing apparatus 10 can be said to be a high-speed functioning apparatus because the processing need not be performed.

When generating the data for reverse printing, the printing apparatus 10 reads out the compressed raster data in descending order of raster number (in order of decreasing raster number), and reads out each read compressed raster data. After being extended, it is turned left and right to form a device. That is, the printing apparatus 10
Since the compressed data of the above-described form is adopted, the apparatus is capable of inverting an image after being compressed. If the technique used in the printing apparatus 10 according to the embodiment is used, Thus, a printing apparatus capable of performing double-sided printing can be realized without adding a function of generating image data of an inverted image. If it is better not to perform reverse printing for some unexpected reason, it is possible to realize a printing apparatus that performs normal printing.

<Modification> Printing apparatus 10 according to the embodiment
Can perform various deformations. For example, the printing apparatus 10 is an apparatus that receives print data from the host computer 50 and performs color printing.
0 may be applied to a printing apparatus capable of performing only monochrome printing, or to a monochrome or color copying machine. Further, the printing apparatus 10 according to the embodiment includes the address tables 202 _{1 to} 202 ₄ and the compressed data storage area 20.
1 is provided on the same memory 20 (the address tables 202 _{1 to} 202 ₄ and the compressed data storage area 201).
Are not accessible at the same time), but the address tables 202 _{1 to} 202 ₄ and the compressed data storage area 20
1 may be provided on another memory.

The printing apparatus 10 is an apparatus in which compressed raster data is generated by an ASIC (color conversion processing section 18 and compression processing section 19) provided in the printing apparatus 10. May be performed on the host computer 50 side.

[0044]

According to the present invention, there are provided a printing apparatus capable of efficiently performing clipped printing and a printing apparatus capable of performing high-speed reverse printing, wherein an image is inverted when compressed data is expanded. A printing device is obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printing apparatus according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of a compression processing unit provided in the printing apparatus according to the embodiment.

FIG. 3 is an explanatory diagram of a compressed data storage area in which compressed raster data is stored by a compression processing unit.

FIG. 4 is an explanatory diagram of an address table in which a raster address and the number of raster bytes are stored by a compression processing unit;

FIG. 5 is a schematic configuration diagram of a decompression processing unit provided in the printing apparatus according to the embodiment.

FIG. 6 is an explanatory diagram of an operation of a decompression processing unit during normal printing.

FIG. 7 is an explanatory diagram of an operation of the decompression processing unit during reverse printing.

FIG. 8 is an explanatory diagram of a storage format of compressed raster data in a memory.

[Explanation of symbols]

 Reference Signs List 10 printing apparatus 11 control unit 12 printing mechanism unit 13 print engine 15 host interface unit 16 ROM 17 CPU 18 color conversion processing unit 19 compression processing unit 20 memory 21 expansion processing unit 191 compression circuit 201 compressed data storage area 202 address table 211 DMA circuit 212 Expansion circuit 213 Left and right clip circuit 214 Left and right inversion circuit

Claims (4)

[Claims] A print execution unit that receives supply of a plurality of raster data for defining one line of drawing content and forms an image on a sheet according to the supplied plurality of raster data; Storage means; second storage means; for each of a plurality of ordered raster data representing an image to be processed, generate compressed raster data obtained by compressing the raster data; Compression processing means for storing, in the second storage means, information indicating a storage position of each compressed raster data in the first storage means, and storing the information in the second storage means; With reference to the information, some of the plurality of compressed raster data stored in the first storage means are stored in the compressed raster data relating to a portion for which printing of the processing target image is designated. Sequentially reads according to metadata the order, the printing apparatus characterized by by decompressing each compressed raster data read and a decompression means having a function of supplying to said print execution means. 2. The method according to claim 1, wherein the decompression processing means further comprises:
With reference to the information stored in the storage means, the plurality of compressed raster data stored in the first storage means are sequentially read out in an order reverse to the above order, and for each read compressed raster data, After decompressing the compressed raster data, an inverse decompression function is provided that generates data in which the arrangement order of the pixel data constituting the raster data obtained by decompression is reversed and supplies the data to the print execution unit. The printing device according to claim 1. 3. The decompression processing means further comprises:
Among the plurality of compressed raster data stored in the storage means, some compressed raster data relating to a portion for which printing of the processing target image is designated is sequentially read out in the reverse order to the above-mentioned order, and For the compressed raster data, after decompressing the compressed raster data, an inversion decompression function for generating data in which the arrangement order of the pixel data constituting the raster data obtained by decompression is reversed and supplying the data to the print execution means, The printing apparatus according to claim 1, further comprising: 4. A print execution means for receiving a plurality of raster data defining the rendering content for one line and forming an image on a sheet in accordance with the plurality of supplied raster data. Storage means; second storage means; for each of a plurality of ordered raster data representing an image to be processed, generate compressed raster data obtained by compressing the raster data; Compression processing means for storing, in the second storage means, information indicating a storage position of each compressed raster data in the first storage means, and storing the information in the second storage means; With reference to the information, the plurality of compressed raster data stored in the first storage means are sequentially read out in an order reverse to the above order, and each read compressed raster data is read out. And decompression processing means having a function of generating data obtained by reversing the arrangement order of the pixel data constituting the raster data obtained by decompression and then supplying the data to the print execution means. A printing apparatus, comprising: