JPH10151815A - Printing-processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniform a burden of each developing processing part and improve efficiency when a plurality of developing processing parts for rasterization are provided to raster scan data in a dispersed manner. SOLUTION: Printing data are input to a generating processing part 3 via a printing data input part 2, and converted to intermediate data which is basically trapezoidal. The intermediate data are input to a plurality of developing processing parts 4 simultaneously. Each developing processing part 4 develops the data to a bit map at a scan line designated by a developing scan line- designating part among areas where the intermediate data are plotted, and stores in a 1/N page buffer 522. When the whole intermediate data are totally developed to the bit map at the whole of the developing processing parts 4, the data are transferred by a read part 6 to an output part 7 and printed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a print processing apparatus which is particularly effective for graphics processing of a printer controller.

[0002]

2. Description of the Related Art With the development of an electrophotographic page printer suitable for small, high-speed digital printing, images, figures, characters, and the like, which have escaped from the conventional printing of mainly character information, are handled in the same manner. 2. Description of the Related Art A printing processing apparatus using a description language in which enlargement, rotation, deformation, and the like of an image can be freely controlled has been widely used. As a representative example of this description language, Pos
tScript (trademark of Adobe Systems, Inc., USA), Interpress (trademark of Xerox, USA), Acrobat (Adobe System, USA)
s company trademark), GDI (Graphics Device)
Interface, a trademark of Microsoft Corporation in the United States) and the like are known.

[0003] Print data created in a description language is:
A drawing command for expressing an image, a figure, and a character at an arbitrary position in a page is configured in an arbitrary order, and in order to print with the page printer according to the present invention, the print data must be rasterized before printing. No. Rasterization is
This is the process of developing a raster scan line by developing it into a series of individual dots or pixels that traverse the page or part of the page, and successively generating successive scan lines below the page. This image processing is very costly, and how to perform this processing at high speed has been a long-standing problem.

[0004] As one technique for this purpose, a technique for parallelizing processing for expanding into bitmap data has been proposed. This prior art is disclosed in JP-A-6-214555. In this prior art, a plurality of decompression processing means for decompressing intermediate data are provided, each decompression processing means has one page of storage means, and a reading unit is connected to these decompression processing means. . In this prior art, the intermediate data obtained by interpreting the print data is divided into the number of expansion processing units and distributed to each expansion processing unit, and each expansion processing unit processes only the assigned intermediate data, The developed bitmap data is temporarily stored in the storage means. Priority data is recorded in each pixel of the storage means, and by comparing with priority data of other storage means, it is possible to determine which storage means to use data stored in for each pixel. it can. The reading unit performs the operation of specifying the storage unit, and outputs the bitmap data to the output unit while switching the storage unit that stores the bitmap data to be printed.

[0005]

However, according to the above-mentioned prior art, each intermediate data is distributed to a certain expansion processing means. Therefore, depending on the distribution of the intermediate data, it is necessary to expand the data into bitmap data. There may be a difference in the amount of calculation. When the performance of the expansion processing means is the same, the difference in the amount of calculation required for expansion will cause a difference in the expansion end time, and the other expansion processing means will be in an idle state to wait for the expansion end of one expansion processing means. It is highly likely that parallel processing cannot be performed efficiently.

Further, since each of the plurality of storage means holds one page of bitmap data, there is a problem that a large amount of expensive memory is used.

Further, it is necessary for the read section to give priority information for indicating which storage means of the plurality of storage means to read from, to each pixel of the bitmap data.

In view of such a conventional problem, the present invention transfers each intermediate data to all expansion processing means, and each expansion processing means transmits the intermediate data bits of a part of the non-overlapping area. By being in charge of map development, it is possible to more evenly distribute loads in the development processing means. At this time, each storage means holds only bitmap data of a part of the areas which do not overlap each other, and the total memory capacity of the plurality of storage means is at least a minimum for storing the bitmap data. It is possible to reduce only the necessary memory amount. further,
The reading unit switches the storage unit according to the area of the bitmap data to be read, so that it is not necessary to specify the storage unit in pixel units of the bitmap data.

[0009]

In order to solve such a problem, the present invention is to input print data describing print contents in a predetermined language, and develop the print data into bitmap data. A print processing apparatus for outputting the print data, converting the print data into a drawing command and outputting the drawing command, and outputting N (N is an integer of 2 or more) pieces of the drawing command and outputting bitmap data; Expansion processing means, corresponding to each of the expansion processing means, N storage means for temporarily holding bitmap data, reading means for selectively reading bitmap data from the N storage means, Output means for outputting the bitmap data read by the reading means, wherein the drawing command generated by the generation processing means is used for the N development processing. Is input to all means, the N
Expansion processing means selectively generate only bitmap data of a corresponding specific scan line in accordance with the input drawing command, and among the N storage means,
The n-th (0 ≦ n <N) storage means holds the bitmap data generated by the n-th expansion processing means,
The reading means switches the storage means in accordance with a scan line to be read.

In this configuration, each development processing means performs bitmap development of a part of the same drawing command, so that the load distribution in the development processing means can be equalized as much as possible. In addition, each storage means holds only bitmap data of a specific area which does not overlap with each other, so that the total memory capacity of the plurality of storage means and the minimum memory capacity required for storing the bitmap data are stored. It is possible to suppress only.

Further, in this configuration, the n-th expansion processing means can selectively generate only the bitmap data of the scan line in which the remainder of the scan line number 1 by N is n. .

Further, when the line number of the scan line to be read is 1 and the number of remainders of 1 by N is n, the read means can read from the n-th storage means.

Further, each of the N storage means may have a size of 1 / N of a capacity for storing bitmap data corresponding to one page of the print data.

[0014] The N storage means may include at least two storage means.
And the N number of rasterization processing units switch bitmap data generated for each of the divided areas obtained by dividing one page of the print data for each of the divided areas, and The data is supplied to N storage units, and each of the storage units has a size of 1 / N of a capacity for storing the bitmap data of the divided area.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a print processing apparatus according to the present invention will be described below with reference to the drawings. [Embodiment 1] FIG. 1 is a block diagram showing an embodiment of a print processing apparatus according to the present invention. In FIG. 1, the print processing apparatus includes a print data creation unit 1, a print data input unit 2, a generation processing unit 3, at least one expansion processing unit 4, a read unit 6, and an output unit 7. ing. further,
The expansion processing unit has a 1 / N page buffer 522 for temporarily storing the expanded bitmap image. Where 1
The / N page buffer 522 is an area for holding 1 / N of the bitmap image (print data) of one page.

The print data creating section 1 has a function of creating print data described in a description language from document data generated by an application program for processing document creation and editing in a personal computer or a workstation. Things. The description language targeted in this embodiment is, for example, GDI, but is a PDF (Portable Document) represented by Acrobat.
t Format) or a page description language represented by PostScript.

The print data input unit 2 has a communication function for inputting the print data generated by the print data creation unit 1,
Alternatively, it has a function of temporarily storing print data until the print data is output to the generation processing unit 3.

The generation processing section 3 generates intermediate data from the print data input from the print data input section 2 and can be expanded into print data in the expansion processing section 4. The purpose of generating the intermediate data is to enable high-speed expansion processing in the expansion processing unit 4. Therefore, the intermediate data is represented by a set of simple figures (for example, trapezoids).

The development processing unit 4 receives the intermediate data output from the generation processing unit 3 and creates bitmap data of the scan line designated by the development scan line designating unit (designated by reference numeral 54 in FIG. 8). 1 / in the expansion processing unit 4
Print data is created in the N page buffer 522. At this time, the data stored in the 1 / N page buffer 522 is bitmap data composed of only the scan lines specified by the expanded scan line specifying unit 54 (FIG. 8).

The reading section 6 reads the bitmap data accumulated in the plurality of 1 / N page buffers 522 while switching the 1 / N page buffer 522 in accordance with the scan line to be read, and transfers it to the output section 7.

The output unit 7 receives the print data output from the read unit 6, prints it on recording paper, and outputs it. As an example, exposure, development, CMYBk (cyan, magenta, yellow, black)
A color page printer using an electrophotographic system of a laser scanning system capable of outputting a full-color image by repeating transfer is exemplified.

Next, the flow of print data in the print processing apparatus configured as described above will be summarized. The print data created by the print data creation unit 1 is input to the generation processing unit 3 via the print data input unit 2. And
The generation processing unit 3 converts the data into intermediate data based on a trapezoid. The intermediate data generated by the generation processing unit 3 is input to a plurality of expansion processing units 4 at the same time.

In each of the expansion processing sections 4, bitmap expansion is performed on the scan line designated by the expansion scan line instructing section 54 (FIG. 8) in the area where the intermediate data is drawn, and the 1 / N page buffer 522 Is accumulated in When the bitmap expansion of all the intermediate data is performed in all the expansion processing units 4 in this way, the reading unit 6 transfers the data to the output unit 7 and prints the data. At this time, the 1 / N page buffer 522 is sequentially switched according to the scan line to be read. For color printers,
The development of the development processing unit 4 into print data and the printing of the output unit 7 are repeated for each color. Further, when the print data includes a plurality of pages, the process is repeated until the output of all pages is completed.

The outline of the print processing apparatus of the present invention has been described above. Next, details of a main part of the print processing apparatus will be described.

First, the generation processing unit 4 will be described in detail. FIG. 2 shows details of the generation processing unit. In this figure, the generation processing unit 4 includes a lexical analysis unit 30, a token interpretation unit 31, an instruction execution unit 32, an image processing unit 33, and a drawing state storage unit 34. A vector data generation unit 35, a font management unit 36, a matrix conversion unit 37, a short vector generation unit 38, a trapezoid data generation unit 39, a trapezoid data management unit 40, and a trapezoid data storage unit 42. Is done.

The lexical analysis unit 30 cuts out the print data input from the print data input unit 2 as a token according to the syntax of a predetermined description language, and outputs the token to the token interpretation unit 31. The token interpreter 31 interprets the token input from the lexical analyzer 30, converts the token into an internal instruction, and sends the internal instruction to the instruction executing unit 32.
The command execution unit 32 includes an image processing unit 33, a drawing state storage unit 34 in accordance with a command transmitted from the token interpretation unit 31,
The data is transferred to the vector data generator 35. Image processing unit 33
Performs various types of image processing based on the input image header and image data to generate an output image header and output image data, and transfers them to the trapezoid data management unit 40. The drawing state storage unit 34 stores information required for drawing given by a command from the command execution unit 32. Vector data generator 35
Generates vector data to be drawn using the command of the command execution unit 32 and the information added thereto, the information from the drawing state storage unit 34, and the information from the font management unit 36,
The data is transferred to the matrix conversion unit 37. Font management unit 3
Reference numeral 6 manages and stores outline data of various fonts, and provides outline data of characters as required. The matrix conversion unit 37 stores the vector data input from the vector data generation unit 35 in the drawing state storage unit 3
Affine transformation is performed by the transformation matrix of No. 4 and transferred to the short vector generation unit 38. The short vector generation unit 38 converts a vector corresponding to the curve in the input vector into a plurality of linear vector sets (short vector).
And sends it to the trapezoid data generator 39. The trapezoid data generation unit 39 generates trapezoid data to be drawn from the input short vector, and transfers the trapezoid data to the trapezoid data management unit 40. The trapezoid data management unit 40 adds the management information and the color information input from the drawing state storage unit 34 and the image processing unit 33 to the input trapezoid data, and transfers them to the expansion processing unit as intermediate data. The processing from the token interpretation unit 31 to the transfer of the intermediate data to the expansion processing unit 4 described above is repeatedly performed every time a drawing command is input.

Hereinafter, the operation of each unit of the generation processing unit 3 will be described in more detail while showing the actual data structure.

The token interpreter 31 interprets the token input from the lexical analyzer 30, converts the token into an internal command and its arguments, and transfers a set of these internal commands and arguments to the instruction executing unit 32. For example, the internal commands include a drawing command for executing drawing of characters / graphics / images, and a drawing state command for setting information required for drawing such as color and line attribute.

The instruction execution unit 32 executes the internal instruction sent from the token interpretation unit 31. The commands executed here mainly include a drawing command and a drawing state command. For example, there are three types of drawing commands as shown in Table 1,
Information necessary for each drawing is shown. Among them, information with an underline is given as an argument in a drawing command, and other information is stored in the drawing state storage unit 34 in advance by initial setting, a preceding command, or the like. For the execution of the drawing command, the received drawing command other than the image drawing is transferred to the vector data generating unit 35 as it is.
In the case of image drawing, the received drawing command is sent to the image processing unit 3.
3 and the vertical and horizontal sizes of the image header are transferred to the vector data generator 35. For the drawing state command, the command is transferred to the drawing state storage unit 34.

[0030]

[Table 1] The image processing unit 33 performs an affine transformation on the input image header and the input image data, which are the arguments of the command input from the command execution unit 32, using the conversion matrix acquired from the drawing state storage unit 34, and performs color conversion of the input image. It performs processing such as color space conversion for converting the space to the color space of the output device, generates an output image header and output image data, and generates a trapezoidal data management unit 4.
Transfer to 0.

The drawing state storage unit 34 sets values of, for example, information without underline shown in Table 1 with the values of the arguments included in the command received from the command execution unit 32, and stores them. In addition, these values are transferred according to requests from the image processing unit 33, the vector data generation unit 35, the matrix conversion unit 37, the short vector generation unit 38, the trapezoid data management unit 40, and the like.

In the vector data generating unit 31, the command and the argument transmitted from the command executing unit 32, the drawing state storing unit 3
Using the value of 3, vector data for new drawing except for the solid drawing is generated. First, the case of character drawing will be described. The character code given by the argument and the font ID obtained from the drawing state storage unit 33 are transferred to the font management unit 36 to obtain character outline data. Since the acquired outline data does not include information on the drawing origin (current point), the target vector data is generated by adding the offset of the current point acquired from the drawing state storage unit 34 to the outline data. In the case of image drawing,
A rectangular vector corresponding to the vertical and horizontal sizes of the image header given by the argument is generated, and the target vector data is generated by adding the offset of the current point acquired from the drawing state storage unit. In the case of stroke drawing, the vector given by the argument and the drawing state storage unit 3
An outline vector of a line having a thickness as shown in FIG. The vector generated in this manner (in the case of the solid drawing, the vector directly received from the instruction execution unit 32) is transferred to the matrix conversion unit 37.

The font management unit 36 stores outline vector data for various fonts,
Outline vector data for the character is provided by the given character code and font ID.

The matrix conversion unit 37 performs affine transformation on the vector data received from the vector data generation unit 35 using the conversion matrix obtained from the drawing state storage unit 34. The main purpose of the affine transformation is to convert the resolution (coordinate system) of the application to the resolution (coordinate system) of the printer. A 3 × 3 matrix as shown in the following equation (1) is used for the conversion matrix, and the input vector data (Xn, Yn) is converted into output vector data (Xn ′, Yn ′) and sent to the short vector generation unit 38. Sent.

[0035]

(Equation 1) The short vector generation unit 38 converts a curve vector into a plurality of vectors so that an error is smaller than a flatness value obtained from the drawing state storage unit 34 when the input vector includes a curve vector. Perform the approximation process using the short vector. For example, a Bezier curve represented by four control points shown in FIG. 4 is used as a curve vector. In this case, the short vector processing recursively divides the Bezier curve as shown in FIG.
The division ends when the height (distance d) becomes smaller than the value given by the flatness. Then, the start point and the end point of each of the divided Bezier curves are connected in order, thereby completing the short vectorization. The generated short vector is sent to the trapezoid data generator 39.

The trapezoid data generation unit 39 generates a set of trapezoid data (in some cases, a triangle, but the data structure is the same as the trapezoid) indicating the drawing area from the input vector data. For example, a polygonal vector indicated by a bold line shown in FIG. 5A has a drawing area indicated by four trapezoids. This trapezoid is a trapezoid having two sides parallel to the scan line of the output device, and one trapezoid has 6 (sx, sy, x0, x1, x2, h) as shown in FIG. It is represented by two data. The generated trapezoid is transferred to the trapezoid data management unit 40.

The trapezoid data management unit 40 generates intermediate data by adding additional information to the input trapezoid data, and transfers the intermediate data to the expansion processing unit 4. The additional information is management information for managing the intermediate data and color information indicating in what color the trapezoidal data is to be painted. The management information for the character / graphic drawing command is data of the object ID, the type of the object, and the number of trapezoids. For example, the value of CMYBk is the color information. These data are added before the trapezoid data generated by the drawing command, as shown in FIG. The management information for the image drawing command is text /
It is the same as a figure, but the color information is an image header and image data. Further, as shown in FIG. 6B, one image header and one image data are added to each of the trapezoidal data for each band generated by the drawing command. Although the image header and the image data are input from the image processing unit 33, the image data added as the intermediate data may be the image data for the minimum rectangle of the vector indicating the converted image as shown in FIG. Alternatively, the image data may be image data corresponding to a minimum rectangle for each trapezoid. Further, since the image data has a large capacity, it may be stored in a compressed form.

Next, the expansion processing section 4 will be described in detail. FIG. 8 shows a block diagram of the development processing unit 4. The intermediate data transferred from the generation processing unit 3 is temporarily stored in the memory unit 52.
Is written to the work memory 521. The drawing unit 53
The intermediate data is read from the work memory 521, bitmap development is performed on the scan line indicated by the development scan line instruction unit 54, and the data is drawn in the 1 / N page buffer 522.

The print data transfer control unit 51 determines that the drawn 1
The read print data is read from the / N page buffer 522, converted into serial data for each read word, and output to the output unit 7 under the control of the read unit 6. The refresh control unit 54 includes a work memory 521,
The refresh of the storage unit 52 including the 1 / N page buffer 522 is controlled. When each of the drawing unit 53, the refresh control unit 54, the intermediate data transfer control unit 50, and the print data transfer control unit 51 accesses the memory unit 52, the arbitration unit 55 controls arbitration according to the access priority of each block. I do.

The drawing section 53 converts trapezoidal data (sx, sy, x0, x1, x2, h) constituting the input intermediate data into
The data is converted into a data format composed of four points as shown in FIG. 10, and the scan line indicated by the developed scan line designating unit is drawn in the trapezoidal area.

FIG. 9 shows a block diagram of the drawing section 53.
The intermediate data input unit 530 reads data forming a trapezoid one by one from the work memory, and reads the coordinate calculation unit A531.
And the trapezoid data is output to the coordinate calculation unit B532. The coordinate calculation unit A531 outputs the expanded scan line instruction unit 54 from the left edge of the trapezoid (the edge P0P1 in FIG. 10).
Is in charge of calculating the coordinates of the edge of the scan line shown in (1), and outputs the coordinate values on the edge in order from P0 to P1. The coordinate calculation unit B532 is in charge of calculating the coordinates of the edge of the scan line indicated by the developed scan line instruction unit among the right edges of the trapezoid (edge P2P3 in FIG. 10), and changes the coordinate values on the edge from P2 to P3. Output in order toward. The edge drawing unit 533 includes a coordinate calculation unit A5
A straight line parallel to the trapezoidal x-axis is drawn based on 31 and the coordinate values input from the coordinate calculation unit B532.

The expanded scan line instructing section 54 is recorded in a current scan line number S, an expanded processing section number n recorded in an expanded processing section number register (not shown), and recorded in an expanded processing section total number register (not shown). The following calculation is performed based on the total number N of the existing expansion processing units 4.

[0043]

Y = S mod N−n Here, S mod N indicates a remainder when S is divided by N. When the scan line satisfies y ≠ 0, no drawing processing request is sent to the coordinate calculation units 531 and 532. y =
When the scan line is 0, the coordinate calculation unit A531 outputs the coordinate value of the intersection between the straight line connecting P0 and P1 and the current scan line, and the coordinate calculation unit B532 outputs the straight line connecting P2 and P3 and the current scan line. The coordinate value of the intersection with is output. As an example, in the case of a print processing apparatus having three rasterization processing sections 4, the first print processing apparatus has the coordinate calculation section 53 when the scan line numbers are 1, 4, 7,.
The calculation is performed at 1,532. In the second print processing apparatus, when the scan line numbers are 2, 5, 8,..., The coordinate calculation units 531 and 532 perform calculations. In the third print processing apparatus, when the scan line numbers are 3, 6, 9,..., The coordinate calculation units 531 and 532 perform calculations. The edge drawing unit 533 includes a coordinate calculation unit A531 and a coordinate calculation unit B5.
A straight line parallel to the trapezoidal x-axis is drawn based on the coordinate values input from 32.

FIG. 11 is a block diagram of the coordinate calculators 531 and 532. Input trapezoidal data (sx, sy,
x0, x1, x2, h) are the DDA parameter calculation unit 53
In 4, the data is converted into four-point trapezoidal data (P 0, P 1, P 2, P 3), and the DDA parameters such as the slope and the initial value of the residual are calculated and output to the DDA processing unit 535. The DDA processing unit 535 performs the DDA processing based on the input parameters.
The processing is performed, and the moving direction and the moving amount for the last obtained point are output. The coordinate updating unit 536 updates the currently held coordinate value based on the input moving direction and moving amount and outputs the updated coordinate value. It is assumed that the initial values of the coordinates are set in advance by a CPU (not shown) or the like.

FIG. 12 is a block diagram of the edge drawing section 533. The edge drawing unit 533 inputs the coordinate values A / B and the image data, and paints the trapezoidal internal area. The address calculator 537 receives the coordinate values A / B and calculates the address of the edge component to be drawn. Mask operation unit 53
Numeral 8 inputs the values of the coordinate values A / B and outputs a mask representing valid bits in the word to be drawn. When the input data is characters / graphics, the data calculation unit 539 inputs color data representing a fixed color by a trapezoidal area, performs screen processing using this value, and outputs the result. If the input data is image data, screen processing is performed on the input image data and the image data is output. RmodW unit 54
For 0, drawing is performed by performing the following processing using the input address, mask, and data. First, the 1 / N page buffer is read according to the address. Assuming that the read data is Source, the mask data is Mask, and the drawing data is Data, (Mask
* Data + Mask # * Source) is calculated and written back to the same address. Here, * represents logical product, + represents logical sum, and # represents logical negation. This process is repeated for each word including the edge to be drawn.

Next, the reading section 6 will be described in detail. FIG. 13 shows a block diagram of the reading unit 6. When the bitmap expansion of the intermediate data in the expansion processing unit 4 is completed, the reading unit 6 starts reading from the 1 / N page buffer in the expansion processing unit designated by the buffer switching unit 60, and scans from the output unit 7. The bitmap data is transferred to the output unit 7 in synchronization with the line synchronization signal.

The buffer switching means 60 includes a scan line number S held in the scan line counter 61,
The following calculation is performed based on the total number N of the expansion processing units 4 stored in the expansion processing unit total number register 62 of the expansion processing unit 4.

[0048]

N = S mod N Then, a bit map memory for one scan line is extracted from the 1 / N page buffer 522 of the n-th expansion processing unit 4 and transferred to the output unit 7. For example, in the case of a print processing apparatus having three rasterization processing units 4, when the scan line number is 1, bitmap data is read from the 1 / N page buffer 522 of the first rasterization processing unit 4,
Transfer to the output unit 7. When the scan line number is 2, the 1 / N page buffer 52 of the second rasterization processing unit 4
2. When the scan line number is 3, the third expansion processing unit 4
1 / N page buffer 522, scan line number 4
1 / N page buffer 5 of the first expansion processing unit 4
1 / N page buffer 522 sequentially read out as 22.
, The bit map data for one scan line is transferred to the output unit 7. This is repeated until all data is transferred to the output unit 7.

The details of the main part of the printing apparatus have been described above.
In the present embodiment, the expansion processing unit 4 and the reading unit 6 have been described as separate modules, but it is desirable that the expansion processing unit and the reading unit are realized by one chip when implementing an LSI. FIG. 14 shows the configurations of the expansion processing unit and the reading unit in this case.
Shown in The buffer switching unit determines whether or not the current scan line has been expanded by this expansion processing unit, based on the values of the expansion processing unit number register, the expansion processing unit total register (not shown), and the scan line register, and outputs the result. I do. The selector 70 selects and outputs 1 / N page buffer in the expansion processing unit or externally input bitmap data based on the output of the buffer switching unit 60. Then, the latch 71 outputs bitmap data according to the output clock sent from the output unit.

As described in this embodiment, one intermediate code is divided in units of scan lines, and the processing is performed by the plurality of expansion processing units 4, so that the load distribution in the expansion processing units 4 can be relatively evenly distributed. Can be Note that DD
The time required for the process A is about 1/3 of the time required for reading and writing the memory. Therefore, the expansion processing unit 4
If N = 3 is specified as the total number of memory cells, the bottleneck of memory input / output is eliminated, and the efficiency becomes higher.

[Second Embodiment] In the first embodiment, the case where bitmap data for one image page is stored in a plurality of 1 / N page buffers has been described. In the second embodiment, a case will be described in which one page of an image is divided into regions (bands) that are horizontal in the direction in which the printing paper is carried out, and bitmap data for one band is stored in a plurality of 1 / N band buffers.

In a conventional page printer, print data of the entire page is rasterized before printing and stored in a page buffer memory. However, storing raster data for an entire page requires a large amount of memory. In particular, in the latest electrophotographic color page printer, C (Cyan), M (Magenta), Y
Raster data corresponding to four color toners (Yellow) and Bk (Black) is required, and image quality is required more than that of a monochrome page printer. Yes, and requires more memory.

In response to this need for a large amount of memory, band memory technology has recently emerged as a technology for reducing the memory capacity from the viewpoint of cost reduction. Band memory technology can rasterize print data created in a description language faster than rasterizing print data instead of rasterizing all print data for one page before printing by a page printer. Convert to relatively simple intermediate data,
This technique divides a page into a plurality of adjacent areas (bands), stores intermediate data corresponding to each band, sequentially transfers the intermediate data to a raster development processing unit, and develops the data in a buffer memory corresponding to the band. In the band memory technology, a memory for storing intermediate data is newly required, but it is possible to reduce a buffer memory that requires a large capacity for raster data.

FIG. 15 is a block diagram showing another embodiment of the print processing apparatus of the present invention. In FIG. 15, the print processing device includes a print data creation unit 1, a print data input unit 2, a generation processing unit 3, a development processing unit 4, and a readout unit 6.
And an output unit 7. Further, the expansion processing unit 4 includes two 1 / N band buffers 525 and 526, respectively.
Having. Here, 1 / N band buffers 525 and 52
Reference numeral 6 denotes an area for holding a 1 / N bitmap image (print data) of one band.

Print data creation unit 1 and print data input unit 2
And the output unit 7 are the same as those in the first embodiment, and the description is omitted here.

The generation processing unit 3 generates intermediate data that can be expanded from the print data input from the print data input unit 2 into print data in the expansion processing unit 4. First, the lexical analysis unit 30 causes the print data input unit 2
The input print data is cut out as a token according to the syntax of a predetermined description language. Then, it interprets the token, executes the drawing command, generates data in the form of a trapezoid for each drawing command as a basic unit, and manages and stores the data as intermediate data for each band. These data are read from the expansion processing unit 4 as needed. The purpose of generating the intermediate data is to enable high-speed expansion processing in the expansion processing unit 4. Therefore, the intermediate data is represented by a set of simple figures (trapezoids), and is classified in band units. The connection between the generation processing unit 3 and the development processing unit 4 uses real-time data transfer that guarantees a transfer band. For real-time data transfer, for example, the isochronous transfer mode of the IEEE 1394 high performance serial bus is used.

The expansion processing unit 4 reads out the intermediate data stored in the generation processing unit 3 in band units, and expands the bit map data of the scan line designated by the development scan line instruction unit 54 in the area within the band. It is created in the 1 / N band buffers 525 and 526 in the processing unit 4. The bitmap data generated as a result of this processing is alternately stored in two 1 / N band buffers 525 and 526 in the expansion processing unit 4.

The reading section 6 is provided for one of the plurality of development processing sections 4.
The bitmap data stored in the / N band buffers 525 and 526 are read out while switching the 1 / N band buffers 525 and 526 according to the scan line to be read out, and transferred to the output unit 7.

Next, the flow of print data in the print processing apparatus configured as described above will be summarized. The print data created by the print data creation unit 1 is input to the generation processing unit 3 via the print data input unit 2. The intermediate data generated by the generation processing unit 3 is input to a plurality of expansion processing units 4 at the same time.

Each of the expansion processing units 4 receives the intermediate data for one band, performs bitmap expansion on the scan line specified by the expansion scan line instructing unit 54, and accumulates them in the buffer memories 525 and 526.
When the cycle-up of the output unit 7 is completed, print data is transferred from the buffer memories 525 and 526 to the output unit 7 line by line in accordance with the recording speed of the output unit 7.
Printing is performed. At this time, the buffer memories 525 and 526 are sequentially switched according to the scan line to be read. In each of the expansion processing units 4, while the print data of one 1 / N band buffer (for example, 525) is being printed, the 1 / N band buffer (for example, 526) on one side is printed.
Is developed until is satisfied with the print data.
The expansion of the print data by the expansion processing unit 4 and the printing by the output unit are repeated for each color until the print data for one page is processed. Further, when the print data includes a plurality of pages, the process is repeated until the output of all pages is completed.

The outline of the print processing apparatus of the present invention has been described above. Next, details of a main part of the print processing apparatus will be described.

First, the generation processing unit 3 will be described in detail. As shown in FIG. 16, the generation processing unit 3 includes a lexical analysis unit 30, a token interpretation unit 31, an instruction execution unit 32,
Image processing unit 33, drawing state storage unit 34, vector data generation unit 35, font management unit 36, matrix conversion unit 37, short vector generation unit 38, trapezoid data generation unit 39, band decomposition unit 41 And a trapezoidal data management unit 40 and a trapezoidal data storage unit 42.

The token interpreter 31 and the instruction executor 32
An image processing unit 33, a drawing state storage unit 34, a vector data generation unit 35, a font management unit 36, a matrix conversion unit 37, a short vector generation unit 38,
The trapezoid data generation unit 39 and the trapezoid data management unit 40 have the same functions as those in the first embodiment, and thus will not be described here.

The band decomposition section 41 divides the trapezoid data spanning a plurality of bands from the input trapezoid data into trapezoid data for each band, and transfers the trapezoid data to the trapezoid data management section 40 for each band. For example, in FIG. 17, four trapezoidal data are divided into six trapezoidal data by the band decomposition unit.

The trapezoid data storage unit 42 stores the intermediate data generated by the trapezoid data management unit 40 in band units.
The intermediate data is transferred in response to a request from the development processing unit 4.

The above-described processing from the lexical analysis unit 30 to the writing to the trapezoidal data storage unit 42 is repeatedly performed each time a drawing command is input. The transfer of the intermediate data from the trapezoid data storage unit 42 to each of the expansion processing units 4 is performed after the intermediate data for one page is stored.

Next, the expansion processing section 4 will be described in detail. FIG. 18 shows a block diagram of the development processing unit 4. The intermediate data for each band generated by the generation processing unit 3 is read by the intermediate data transfer control unit 50 and written to the input buffer A 523 or the input buffer B 524 of the memory unit 52. The drawing unit 53 reads the intermediate data from the input buffer A 523 or the input buffer B 524, performs bit map development on the scan line indicated by the developed scan line instructing unit 54, and executes the 1 / N band buffer A 525 or the 1 / N band buffer. B52
6 is drawn.

The print data transfer control unit 51 determines that the drawn 1
The print data developed from the / N band buffer A 525 or the 1 / N band buffer B 526 is read, the read data is converted into serial data for each read word, and output to the output unit 7 under the control of the read unit 6. The refresh control unit 55 controls refresh of the memory unit 52 including the input buffer A 523, the input buffer B 524, the 1 / N band buffer A 525, and the 1 / N band buffer B 526. The arbitration unit 56 includes a drawing unit 53, a refresh control unit 54, an intermediate data transfer control unit 50, and a print data transfer control unit 51, each of which is a memory unit 5.
When accessing block 2, arbitration control is performed according to the access priority of each block.

A method of using the input buffer and the 1 / N band buffer will be described. FIG. 19 (a) and FIG.
(B) shows the use state of each buffer while the intermediate data is being input to the input buffer A and the input buffer B, respectively. In FIG. 19A, intermediate data corresponding to band i is being input to input buffer A, and intermediate data corresponding to band (i-1) has already been input to input buffer B. The drawing unit 53 reads the intermediate data stored in the input buffer B, performs bitmap development on the scan line indicated by the developed scan line instruction unit 54, and renders the data in the 1 / N band buffer B.
The 1 / N band buffer A stores print data as a result of developing and rendering intermediate data corresponding to the band (i-2), and the print data transfer control unit 51 reads this to the output unit 7. .

In FIG. 19B, the band (i +
The intermediate data corresponding to 1) is being input to the input buffer B, and the intermediate data corresponding to the band i has already been input to the input buffer A. The rendering unit 53 reads the intermediate data stored in the input buffer A, performs bitmap development on the scan line indicated by the development scan line instruction unit 54, and renders the data in the 1 / N band buffer A. The 1 / N band buffer B stores print data as a result of developing and rendering intermediate data corresponding to band (i-1), and the print data transfer control unit 51 reads this to the output unit 7. .

The processing of the drawing unit 53 and the reading unit 6 is the same as that of the first embodiment except that the unit of the processing of the intermediate data is one page and one band, so that the description is omitted here.

The details of the main part of the printing apparatus have been described above.
In the present embodiment, the expansion processing unit 4 and the reading unit 6 have been described as separate modules, but it is desirable that the expansion processing unit and the reading unit are realized by one chip when implementing an LSI. In this case, the expansion processing unit and the reading unit can be configured as shown in FIG. 14 similarly to the first embodiment.

Also in the present embodiment, one intermediate code is divided in units of scan lines, and processing is performed by a plurality of expansion processing units, so that the load distribution in the expansion processing units can be relatively equalized. . Note that the time required for the DDA process is about one third of the time required for reading and writing the memory. Therefore, if N = 3 is specified as the total number of the expansion processing units, the bottleneck of the memory input / output is eliminated, and the efficiency is improved.

In the above embodiment, the developing unit is switched every scan line.
The development processing unit may be switched in units of a plurality of scan lines.

[0075]

As described above, according to the present invention, each development processing means develops a part of the same drawing command as a bit map, so that the load distribution in the development processing means is made as uniform as possible. It becomes possible. In addition, each storage means holds only bitmap data of a specific area which does not overlap with each other, so that the total memory capacity of the plurality of storage means and the minimum memory capacity required for storing the bitmap data are stored. It is possible to hold down only to. Further, the reading unit switches the storage unit according to the area of the bitmap data to be read, so that it is not necessary to specify the storage unit in the pixel unit of the bitmap data.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a generation processing unit according to the first embodiment.

FIG. 3 is a diagram illustrating an outline vector of Example 1.

FIG. 4 is a diagram illustrating recursive division of a Bezier curve.

FIG. 5 is a diagram illustrating trapezoidal data.

FIG. 6 is a diagram illustrating an example of a data representation of trapezoid data.

FIG. 7 is a diagram for explaining correspondence of image data to trapezoidal data.

FIG. 8 is a block diagram illustrating a development processing unit according to the first embodiment.

FIG. 9 is a block diagram illustrating a drawing unit according to the first embodiment.

FIG. 10 is a diagram illustrating trapezoidal data drawing by a drawing unit. .

FIG. 11 is a block diagram illustrating a coordinate calculation unit according to the first embodiment.

FIG. 12 is a block diagram illustrating an edge drawing unit according to the first embodiment.

FIG. 13 is a block diagram illustrating a reading unit according to the first embodiment.

FIG. 14 is a block diagram when the development processing unit and the reading unit are realized by one chip.

FIG. 15 is a block diagram showing a second embodiment of the present invention.

FIG. 16 is a block diagram illustrating a generation processing unit according to the second embodiment.

FIG. 17 is a diagram illustrating division of trapezoidal data at a band boundary.

FIG. 18 is a block diagram illustrating a development processing unit according to the second embodiment.

FIG. 19 is a diagram illustrating how to use an input buffer and a 1 / N band buffer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print data creation part 2 Print data input part 3 Generation processing part 4 Expansion processing part 6 Reading part 7 Output part 30 Lexical analysis part 31 Token interpretation part 32 Command execution part 33 Image processing part 34 Drawing state storage part 35 Vector data generation part 36 font management unit 37 matrix conversion unit 38 short vector generation unit 39 trapezoidal data generation unit 40 trapezoidal data management unit 41 band decomposition unit 42 trapezoidal data storage unit 50 intermediate data transfer control unit 51 print data transfer control unit 52 memory unit 521 work memory 522 page buffer 523 input buffer A 524 input buffer B 525 1 / N band buffer A 526 1 / N band buffer B 53 drawing unit 54 development scan line instructing unit 55 refresh control unit 56 arbitration unit 530 intermediate data input 531 Coordinate calculation unit A 532 Coordinate calculation unit B 533 Edge drawing unit 534 DDA parameter calculation unit 535 DDA processing unit 536 Coordinate update unit 537 Address calculation unit 538 Mask calculation unit 539 Data calculation unit 540 RmodW processing unit 60 Buffer switching unit 61 Scan line Counter 62 Total number of expansion processing units register 70 Selector 71 Latch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Noriaki Seki 430 Nakaicho, Nakaicho, Ashigarakami-gun, Kanagawa Prefecture Inside Fuji Xerox Fuji Xerox Co., Ltd. In company

Claims (5)

[Claims] 1. A print processing apparatus for inputting print data describing print content in a predetermined language, developing the print data into bitmap data and outputting the bitmap data, wherein the print data is input and converted into a drawing command (N is an integer of 2 or more) expansion processing means for inputting the drawing command and outputting bitmap data, and a bitmap corresponding to each of the expansion processing means N storage means for temporarily holding data; reading means for selectively reading bitmap data from the N storage means; and output means for outputting bitmap data read by the reading means. The drawing command generated by the generation processing means is input to all of the N development processing means, and the N development processing means Only the bitmap data of the corresponding specific scan line is selectively generated according to the input drawing command, and the n-th (0 ≦ n <N) storage unit of the N storage units is: A print processing apparatus which holds bitmap data generated by an n-th raster processing unit, and wherein the reading unit switches the storage unit in accordance with a scan line to be read. 2. The apparatus according to claim 1, wherein the n-th expansion processing means selectively generates only bitmap data of a scan line whose remainder of the scan line number 1 by N is n. Print processing device. 3. The apparatus according to claim 2, wherein when the line number of the scan line to be read is 1, and the number of remainders of N by 1 is n, the reading means reads from the n-th storage means. Print processing device. 4. The apparatus according to claim 1, wherein each of the N storage units has a size of 1 / N of a capacity for storing bitmap data corresponding to one page of the print data. 4. The print processing device according to 2 or 3. 5. The image forming apparatus according to claim 1, wherein at least two sets of the N storage units are provided, and the N expansion processing units include a bit map generated for each of the divided areas obtained by dividing one page of the print data. Data is switched for each of the divided areas and supplied to the at least two sets of N storage means, each of which has a size of 1 / N of a capacity for storing bitmap data of the divided area. The print processing apparatus according to claim 1, further comprising: