JPH10157217A - Printing-processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately control an output speed of an output device in accordance with complexity of printing data in a printing-processing apparatus wherein a memory storing raster data is constituted of a band memory. SOLUTION: A processing time-estimating part 4 analyzes a plotting command when receiving a token output from a word-analyzing part 30, generates plotting element data indicating a plotting area and develops the data for every band. A total time of estimated plotting times of the plotting element data of bands and a processing time after the plotting element data are generated before the plotting element data are developed to bands are added, based on which a plotting process estimation time for each band is calculated. The plotting process estimation time of each band is collected for every page and output to an output control part 5. The output control part 5 controls a recording speed of an output part 6 based on the plotting process estimation time of each band for every page input from the processing time-estimating part 4 so that an output of the output part 6 does not exceed the plotting process estimation time of each band.

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 using a page printer. More specifically, a buffer memory for temporarily storing print data to be output by a page printer is a band memory. The present invention relates to a print processing apparatus configured.

[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 Incorporated), I
terpress (trademark of Xerox Corporation, USA), Ac
robot (trademark of Adobe Systems, Inc.), GDI
(Graphics Device Interface
e, a trademark of Microsoft Corporation, USA).

[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. In a conventional page printer, print data of an 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. Especially,
In the latest electrophotographic color page printer, C
(Cyan), M (Magenta), Y (Yellow)
w) and Bk (Black) require raster data corresponding to four color toners, and image quality is required more than a monochrome page printer, so that it is common to have a plurality of bit information per pixel. , Requires even more memory.

In response to the need for a large amount of memory, band memory technology has recently emerged as a technology for reducing memory requirements 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. However, in a general band memory technique, it is necessary to finish developing raster data from intermediate data for the next band before printing of raster data of a certain band is completed. When the print data includes a complicated graphic drawing instruction or an image drawing instruction with a large amount of data to be handled, or when a specific band in one page includes a complicated graphic drawing instruction or an image drawing instruction, There is a possibility that a situation may occur where the development of the intermediate data into the raster data is not in time.

Therefore, several techniques have been proposed to cope with the above-mentioned problems relating to the band memory technique.
No. 07, JP-A-6-344639 and the like are known.

[0006]

Problems to be Solved by the Invention
In the print processing apparatus described in Japanese Patent Application Laid-Open No. 7, the development processing time from intermediate data of the first format to raster data is measured for each band. If the expansion processing time of a specific band is not enough, the intermediate data in the first format is expanded into raster data in advance, lossless compression processing is performed, and the intermediate data is stored as intermediate data in the second format. . However, the intermediate data in the second format is contrary to the purpose of the original band memory technology, and causes an increase in the memory for storing the intermediate data. The intermediate data of the format is expanded into raster data again, loss compression processing with a high compression ratio is performed, and
It is stored as intermediate data of the format. Therefore,
In the print processing apparatus described in Japanese Patent Application Laid-Open No. 6-290007, even if the print data includes a complicated graphic drawing command or image data, the data can be output by the page printer without data loss. However, there is a problem that image quality is degraded because loss compression processing with a high compression ratio is performed. Further, a process of trying a plurality of intermediate data formats is required to accommodate the data in a predetermined memory, which causes a problem that the processing time of the entire printing process becomes longer.

In the print processing apparatus described in Japanese Patent Application Laid-Open No. 6-344639, input data is transferred from a host computer to a page printer, and the input data transfer speed is measured. Subsequently, the printing speed of the page printer is controlled based on the measured input data transfer speed, so that a situation in which raster data cannot be expanded in time is prevented. That is, when the input data transfer speed is high, the rotation speed of the page printer is increased, and when the input data transfer speed is low, the rotation speed of the page printer is reduced. However, in the above configuration, the data format input to the page printer can handle only a data format in which the number of input data is proportional to the number of output data. (In the embodiment, the input data is composed of only font data and raster data.) Therefore, in the print processing apparatus described in Japanese Patent Application Laid-Open No. 6-344639, a complicated graphic described in the above-described description language is used. It cannot respond to print data that includes a drawing command.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and a print processing apparatus comprising a band memory as a storage device for temporarily storing print data to be output by a page printer. The print data containing no complicated graphic drawing instruction described in a description language without causing the deterioration of the image quality due to the complexity of the expansion processing or the lack of the memory capacity as described above is used. It is an object of the present invention to provide a print processing apparatus capable of performing optimal processing according to the degree.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a print processing apparatus for achieving the above object. That is, the present invention provides an input unit that has at least one of a character, a figure, and an image and inputs print data described by a predetermined drawing command, an image output unit, and a type and an attribute of the drawing command. Drawing element generation means for generating drawing element data representing a drawing area from the print data, and developing the drawing element data generated by the drawing element generation means into a data structure that can be output by the image output means. For decomposing drawing element data generated by the drawing element generating means into a plurality of areas in a page, and for each of the areas, at least drawing element data included in the area Drawing time prediction means for predicting the drawing time of the area based on the sum of the drawing prediction times of the areas, and each of the areas predicted by the drawing time prediction means. Depending on the drawing predicted time, and has a configuration and control means for determining an image output speed of the image output unit.

In this configuration, the drawing time predicting means can be configured to predict the drawing time for each band obtained by dividing one page into a plurality of bands.
A drawing command for one page can be configured to be drawn for each of a plurality of divided band areas. Here, the purpose of generating the drawing element data is to accurately obtain a predicted drawing processing time for each band, and includes at least vector data indicating a drawing area and attribute information thereof.

Further, the drawing time predicting means predicts by adding a processing time of the drawing element generating means, a processing time of the area decomposing means, and a predicted drawing time of the total drawing element data for each area. Can be configured.

The image output means has a plurality of image output speeds, and the control means uses one of these output speeds for each page based on the prediction time predicted by the drawing time prediction means. It can be configured to control the image output means. Furthermore, the control means can be configured to determine an image output speed that is slower than the longest predicted drawing time of the band for one page based on the predicted drawing time of each band.

As described above, according to the present invention, the drawing processing time of the drawing command group of the input print data is predicted for each region such as a band, and the image output means of the image output means is based on the drawing processing time prediction for each region. Since the configuration is such that the speed is determined, even in a print processing apparatus including a band memory, a complicated graphic drawing instruction written in a description language is included without deteriorating image quality. The print data can be optimally processed according to the complexity of the print data.

In particular, according to the present invention, the drawing time of each area can be accurately predicted based on the drawing element data, and the speed control of the image output means can be reliably performed based on the prediction time.

[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.

FIG. 1 is a block diagram showing an embodiment of a print processing apparatus according to the present invention. 1, the print processing apparatus includes a print data creation unit 1, a print data input unit 2, a development processing unit 3, a processing time prediction unit 4, an output control unit 5,
And an output unit 6. Further, the expansion processing unit 3
Is composed of a lexical analyzer 30 and a drawing processor 31.

The print data creation unit 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 expansion processing unit 3.

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 drawing processing unit 31 and the processing time prediction unit 4. Things.

The rendering processor 31 receives and interprets the token output from the lexical analyzer 30, executes a rendering command, and generates raster data. The drawing processing in the drawing processing unit 31 is executed for each band corresponding to the size of the band buffer memory (315, 316 in FIG. 3) in the drawing processing unit 31. The raster data after the drawing processing executed for each band is alternately stored in two band buffer memories in the drawing processing unit 31 as print data. As will be described later, the output unit 6 used in this embodiment is a color page printer, and the print data alternately stored in the band buffer memory is the print data of the recording color printed by the output unit 6. Yes, it is. Subsequently, the print data stored in the band buffer memory is alternately output to the output unit 6 in response to a print data request from the output unit 6. The drawing processing in the drawing processing unit 31 is performed in accordance with the performance of the output unit 6 (resolution, color reproduction characteristics, gradient, recording size, etc.).

The processing time prediction unit 4 receives the token output from the lexical analysis unit 30, interprets the rendering command, and determines the type of the rendering command for each of characters, graphics, and images contained in the print data and the attribute of the rendering command. The rendering element data representing the rendering area is generated, and the rendering element data is decomposed for each band corresponding to the size of the band buffer memory in the rendering processing unit 31. Subsequently, a drawing processing prediction time for each band is obtained based on the addition of the total time of the predicted drawing time of each drawing element data for each band and the processing time from generation of the drawing element data to band decomposition. . The drawing processing prediction time for each band is totaled for each page and output to the output control unit 5. In the present embodiment, the drawing element data is represented by a set of simple figures (for example, trapezoids). The drawing processing in the drawing processing unit 31 includes at least the same processing as the drawing element data generation processing in the processing time prediction unit 4.

The output control section 5 controls the start timing and the recording speed of the output section 6, and the like. More specifically, based on the drawing processing prediction time for each band in page units input from the processing time prediction unit 4, the output unit 6 outputs the output unit 6 such that the output does not exceed the drawing processing prediction time for each band. This controls the recording speed.

The output unit 6 receives print data output from the band buffer memory of the drawing processing unit 31 under the control of the output control unit 5, prints the data on recording paper, and outputs the print data. More specifically, C, M, Y, Bk
(Cyan, magenta, yellow, black) This is a color page printer using a laser scanning type electrophotographic system capable of outputting a full-color image by repeating exposure, development, and transfer for each color.

Here, the configuration and operation of a general laser scanning type electrophotographic color page printer will be described with reference to FIG. In FIG. 2, a video interface 60 inputs print data corresponding to C, M, Y, and Bk color information sequentially transmitted from the rasterization processing unit 3 to a driver (not shown) for controlling the lighting of a semiconductor laser, and Convert to a signal. The semiconductor laser scanning device 61 includes an infrared semiconductor laser, a lens 611, a polygon mirror 610, and the like, and scans the photosensitive drum 62 as a spot light of several tens μm. Photoconductor drum 62
Is charged by the charger 63, and the light signal
An electrostatic latent image is formed. The latent image is converted into a toner image by two-component magnetic brush development on the rotary developing device 64 and is transferred onto a sheet adsorbed on the transfer drum 65. The photosensitive drum 62 cleans excess toner with a cleaner 66. This process is repeated in the order of Y, M, C, and Bk, and multiple transfer is performed on paper. Finally, the sheet is peeled off by the transfer drum 65 and the toner is fixed by the fixing device 67. 6
Reference numeral 8 denotes a paper transport path.

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 lexical analysis unit 30 of the development processing unit 3 via the print data input unit 2. The token extracted from the print data in the lexical analysis unit 30 is input to the drawing processing unit 31 and the processing time prediction unit 4. The processing time prediction unit 4 receives the token, interprets the drawing command, converts the drawing command of each of the characters, graphics, and images included in the print data into drawing element data, and adds the drawing command to the predicted drawing time of each drawing element data. Based on this, the drawing processing prediction time for each band is predicted. The drawing processing prediction time for each band is totaled for each page and output to the output control unit 5. The output control unit 5 outputs the output unit 6 based on the drawing processing time for each band predicted by the processing time prediction unit 4.
Is determined, the output unit 6 is activated, and operation is performed at the determined recording speed.

On the other hand, the drawing processing unit 31 receives and interprets the token, and performs drawing processing until the print data recorded first in the output unit fills the band buffer memory. When the cycle-up of the output unit 6 is completed, print data is transferred from the band buffer memory to the output unit 6 line by line in accordance with the recording speed of the output unit 6, and printing is performed. While the print data of one band buffer memory is being printed, the drawing process is executed until one band buffer memory is filled with the print data. The rendering of the drawing processing unit 30 into print data and the printing by the output unit 6 are repeated for each color until 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 this embodiment has been described above. Next, details of a main part of the print processing apparatus will be described.

First, the drawing processing section 31 will be described in detail.

FIG. 3 is a block diagram showing a configuration example of the drawing processing section 31. The drawing processing unit 31 includes a token interpretation unit 31
0, a command storage unit 311, a command control unit 312, a drawing element data generation unit 313, a drawing unit 314, two band buffer memories (A / B) 315 to 316, and a print data transfer control unit 317. It is composed of

The token interpreter 310 is used by the lexical analyzer 30
Interprets the tokens input from the server, converts them into internal instructions and their arguments, and stores the set of these internal instructions and arguments in the instruction storage unit 31.
Transfer to 1. 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 rendering command group converted by the token interpretation unit 310 is stored in the command storage unit 311.
Is stored for each page. The command storage unit 311 repeatedly outputs a page-based drawing command group in response to a request from the next-stage command control unit 312.

An instruction control section 312 controls the entire processing of the drawing processing section 31 and is executed by the band buffer memory 3.
The following two processes are repeated by the number of bands for each of the n-divided bands corresponding to the sizes of 15, 316. Process 1: The drawing unit 314 is notified of the change of the band area, and outputs coordinate data representing the band area to be processed. Process 2: The entire drawing command group of the page currently being processed is read from the command storage unit 311 and the drawing command group is output to the drawing element data generation unit 313.

The drawing element data generating section 313 generates drawing element data represented by a trapezoidal figure from the type of the drawing command of the drawing command group input from the command control section 312 and the attribute of the drawing command. FIG. 4 is a block diagram illustrating a configuration example of the drawing element data generation unit 313. The drawing element data generation unit 313 includes an instruction execution unit 320, a drawing state storage unit 321, an image processing unit 322, a vector data generation unit 323, a font management unit 324, a matrix conversion unit 325, and a short vector generation unit. 326 and a trapezoid data generator 327.

The command execution unit 320 responds to the drawing command sent from the command control unit 312,
1. Transfer to the image processing unit 322 and the vector data generation unit 323. The image processing unit 322 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 drawing unit 314. The drawing state storage unit 321 stores information necessary for drawing given by a command from the command execution unit 320. The vector data generation unit 323 generates vector data to be drawn using the command of the command execution unit 320 and information added thereto, information from the drawing state storage unit 321 and information from the font management unit 324, and generates a matrix. Converter 3
Transfer to 25. The font management unit 324 manages and stores outline data of various fonts and provides outline data of characters in response to a request. The matrix conversion unit 325 performs affine transformation on the vector data input from the vector data generation unit 323 using the conversion matrix of the drawing state storage unit 321 and transfers the vector data to the short vector generation unit 326. Short vector generator 326
, Approximates the vector for the curve in the input vector with a vector set (short vector) of a plurality of straight lines, and sends it to the trapezoid data generation unit 327. The trapezoid data generation unit 327 generates trapezoid data to be drawn from the input short vector, and transfers it to the drawing unit 314.

Hereinafter, the operation of each unit of the drawing element data generation unit 313 will be described in more detail while showing the data structure.

The instruction execution unit 320 executes the internal instruction sent from the instruction control unit 321. 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 having an underline is given as an argument in the drawing command, and other information is stored in the drawing state storage unit 321 in advance by initial setting or a preceding command. To execute the drawing command, the received drawing command other than the image drawing is transferred to the vector data generation unit 323 as it is. In the case of image drawing, the received drawing command is transferred to the image processing unit 320, and the vertical and horizontal sizes of the image header are transferred to the vector data generating unit 323. For the drawing state command, the command is transferred to the drawing state storage unit 321.

[0036]

[Table 1] The drawing state storage unit 321 sets, for example, values of information without underline shown in Table 1 with the values of the arguments included in the command received from the command execution unit 320, and stores them. In addition, these values are transferred according to requests from the image processing unit 322, the vector data generation unit 323, the matrix conversion unit 325, the short vector generation unit 326, and the like.

The image processing unit 322 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 320, using the conversion matrix obtained from the drawing state storage unit 313. Transfer to 314.

The vector data generation unit 323 generates vector data for new drawing except for the solid drawing, using the command and argument sent from the command execution unit 320 and the value of the drawing state storage unit 321. I do. 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 are transferred to the font management unit, and character outline data is obtained. Since the acquired outline data does not include information on the drawing origin (current point), the offset of the current point acquired from the drawing state storage unit 321 is added to the outline data.
Generate the desired vector 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 drawing state storage unit 3
The target vector data is generated by adding the offset of the current point obtained from the target 21. In the case of stroke drawing, an outline vector of a line having a thickness is generated from the vector given as an argument and various line attributes acquired from the drawing state storage unit 321. The vector generated in this manner (in the case of a solid drawing, the instruction execution unit 3
20) is transferred to the matrix conversion unit 325.

The font management unit 324 stores outline vector data for various fonts, and provides outline vector data for the character in accordance with a given character code and font ID.

The matrix conversion unit 325 affine-transforms the vector data received from the vector data generation unit 323 using the conversion matrix obtained from the drawing state storage unit 321. 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 3x3 matrix as shown in the following equation (1) is used for the conversion matrix. The input vector data (Xn, Yn) is converted into output vector data (Xn ', Yn') and sent to the short vector generation unit 326. Sent.

[0041]

(Equation 1) The short vector generation unit 317 converts the vector of the curve when the input vector includes the vector of the curve such that the error is smaller than the flatness value acquired from the drawing state storage unit 321. Perform the approximation process using the short vector. For example, a Bezier curve represented by four control points shown in FIG. 5 is used as a curve vector. In this case, the short vector processing recursively divides the Bezier curve as shown in FIG. 5, and ends the division 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 generation unit 327.

The trapezoid data generation unit 327 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 thick line shown in FIG. 6A 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 is represented by (sx, sy, x0, x1, x2, h) as shown in FIG. It is represented by two data. Further, the generated trapezoid data is accompanied by management information indicating the type (character / graphic or image) of the trapezoid data, color information indicating the color of the trapezoid data to be painted, or image data information corresponding to the trapezoid data. After that, it is sent to the drawing unit 314.

Next, the operation from the drawing unit 314 to the print data transfer unit 317 will be described.

The drawing unit 314 performs a drawing process based on the coordinate data representing the band area currently being processed input from the command control unit 312 and the trapezoid data and the image data generated by the drawing element data generation unit 313. Is what you do. The drawing unit 314 performs a clipping process using the coordinate data representing the band area, and draws only the trapezoidal data to be drawn within the band area. First, coordinate data of a vector or a drawing area of an image included in each trapezoidal data is extracted, and a drawing command that is clearly out of the band area is not executed.
Next, for the trapezoidal data in which all the drawing portions are included in the band, the process is executed as it is and the drawing is performed. If only a part of the drawing command is in the band area, whether or not each pixel is in the band area is compared using coordinate values, and only the pixels in the band are drawn. The drawing unit 314 draws alternately in the band buffer memory (A) 316 and the band buffer memory (B) 317 every time the band area to be drawn changes. For example, when the number of the band buffer memory is odd, the drawing is performed on the band buffer memory (A) 316, and when the number is even, the drawing is performed on the band buffer memory (B) 317. Drawing unit 314
Converts the drawing command input from the command control unit 312 into a color space that converts the color space of the input image into the color space of the output device in accordance with the color reproduction characteristics and the gradation of the output unit 6. Drawing is performed while performing dot processing and screen processing such as an FM screen.

The print data transfer control unit 317 reads out the print data for each word from the band buffer memories 315 and 316 on which the drawing has been completed, serially converts this, and outputs it to the output unit 6. The band buffer memory drawing by the drawing unit 314 and the band buffer memory read by the print data transfer control unit 317 always have the opposite relationship. The output to the output unit 6 is performed in synchronization with the serial transfer clock signal input from the output unit 6. Now, the print data transfer control unit 317 stores the band buffer memory (A) 3
It is assumed that data is being read from No. 15. When all the print data has been output to the output unit 6, the drawing unit 3
In 14, drawing to the band buffer memory (B) 316 has already been completed. Therefore, the print data transfer control unit 317
Starts reading the print data from the band buffer memory (B) 316 and outputs it to the output unit 6, and at the same time, notifies the command control unit 312 that the output of the print data from the band buffer memory (A) 315 has ended. . Thereby, the instruction control unit 312 can proceed to the processing of the next band.

Next, the processing time predicting section 4 will be described in detail.

FIG. 7 is a block diagram showing a configuration example of the processing time prediction unit 4. The processing time predicting unit includes the token interpreting unit 4
0, a drawing element data generation unit 41, and a band decomposition unit 42
, A prediction processing unit 43, and a coefficient table 44.

Among the components of the processing time predicting unit, the token interpreting unit 40 interprets the token input from the lexical analyzing unit 30, converts the token into an internal command and its arguments, and converts a set of these internal commands and arguments into a drawing element. The rendering element data generation unit 41 transfers the data to the token interpretation unit 4.
It generates drawing element data represented by a trapezoidal figure from the type of drawing command of the drawing command group input from 0 and the attribute of the drawing command. That is, the token interpreter 40 and the drawing element data generator 41 are the same as the token interpreter 310 and the drawing element data generator 313 of the drawing processor 31. Detailed description of the drawing element data generation unit 41 is omitted.

The band decomposition section 42 extracts trapezoidal data relating to a predetermined band from the trapezoidal data input from the drawing element data generation section 41 and transfers the trapezoidal data to the drawing time prediction section 43 for each band. Further, when the trapezoid data spans a plurality of bands, it is divided into trapezoid data for each band. For example, in FIG. 8, four trapezoidal data are divided into six trapezoidal data by the band decomposition unit, and the trapezoidal data for the band is transferred to the drawing time prediction unit 43.

The print data converted into trapezoidal data in band units by the band decomposing unit 42 is input to the drawing time prediction unit 43 in band units, where the drawing processing time is predicted and integrated for each trapezoid, and Is obtained. Further, the processing time of the drawing element data generation unit 41 and the processing time of the band decomposition unit 42 are added to the drawing processing prediction time in band units, and the result is sent to the output control unit 5 as the drawing processing prediction time in band units.

The calculation of the drawing processing prediction time for the trapezoid data will be described in detail with reference to the flowchart of FIG. It is assumed that the input trapezoid data is described by the data structure shown in FIG.

First, in step 1, the drawing processing predicted time T is set to zero.

Next, in step 2, it is determined whether or not trapezoidal data to be processed remains, and if not, the process proceeds to step 8 and the processing time of the drawing element data generation unit 41 is added to the drawing processing predicted time T. The processing time of the band decomposing unit 42 is added and output to the output control unit 5, and the process is terminated. If it remains, the process proceeds to step 3 and subsequent steps.

Next, in step 3, the next trapezoidal data (sx, sy, x
0, x1, x2, h).

Next, in step 4, the area S of the trapezoid is calculated from the trapezoid data. The area S can be obtained from the trapezoidal data shown in FIG.

Next, in step 5, it is determined whether the type of the trapezoid is a character / figure or an image. If it is a character / figure, the flow proceeds to step 6;

In step 6, trapezoid data and step 4
The predicted time T is updated by performing the calculation according to the equation described in step 6 from the trapezoidal area S obtained in step 2, and the control is shifted to step 2. Similarly, in step 7, the prediction time T is updated by performing a calculation based on the trapezoid data and the area S of the trapezoid obtained in step 4 by using the expression described in step 7, and control is transferred to step 2.

In the above description, the trapezoidal drawing processing prediction time is obtained by weighted addition of the trapezoidal height h and the trapezoidal area S as shown in steps 6 and 7 in FIG. Is determined depending on the trapezoidal drawing processing method in the present embodiment, and a different calculation method is used when another method is used.

The calculation shown in FIG. 9 will be described.
Assuming that the processing time for one line of the process of obtaining the left / right coordinates of a trapezoid by a DA (Digital Differential Analyzer) or the like is a, the processing time required for calculating the left / right coordinates of the trapezoid having a height h is ah Becomes Also, assuming that the processing time for one pixel of the processing for drawing the inside of the trapezoid is b,
The processing time required to draw a trapezoid of area S is bS. The drawing time b per pixel greatly differs between the case of character / graphic data drawing the same pixel value and the case of image data drawing different pixel values for each pixel while referring to the original image data. Therefore, in step 5, the character /
It is configured such that a figure and an image are determined, and in the case of an image, a different coefficient c is used. These coefficients a, b, c
Are set in the coefficient table 44 in advance, and are read out and used by the drawing time prediction unit 43 as necessary.

The coefficient c of the image may vary depending on conditions such as the attribute of the input image and the processing method of the drawing processing unit 31. In such a case, the coefficient c corresponding to each condition is prepared and step 5 is performed. It is necessary to calculate the predicted time by performing the determination processing in detail.

As described above, the drawing processing time prediction in the present embodiment is characterized in that the drawing data is reduced in the degree of abstraction to a level at which the drawing processing time can be accurately predicted in the processing flow of the drawing processing unit. Thus, even if there is locally heavy print data in the page, the drawing processing time can be accurately predicted for each band.

In this embodiment, the processing time of the drawing element data generation unit 41 and the processing time of the band decomposition unit 42 are added to the band-based drawing processing prediction time calculated from the trapezoid data drawing processing time prediction. The drawing processing prediction time in band units was used, but the drawing control processing time in band units calculated from the drawing processing time prediction in trapezoidal data is multiplied by a predetermined coefficient, and the output control unit is used as the band processing prediction processing time. 5 may be output.

Further, in this embodiment, the processing of the band decomposition section 42 and the drawing time prediction section 43 is configured to be sequentially repeated for each predetermined band in accordance with the processing flow of the drawing processing section 31. After the drawing element data of the entire page is decomposed into bands in advance, the drawing time of each band may be predicted.

Next, the output control section 5 will be described in detail.

FIG. 10 is a block diagram showing a configuration example of the output control unit 5. The output control unit 5 includes an output unit status management unit 50
And an output section recording speed selection section 51 and an output section process control section 52.

The output unit state management unit 50 manages the state of the output unit 6 in response to the occurrence of an event associated with a change in the state of the output unit and a state request from the output unit recording speed selection unit 51. Things. Examples of the occurrence of an event due to a change in the state of the output unit 6 include a printing failure due to a failure in the output unit and a paper out condition. Output unit recording speed selection unit 51
Promptly inquires of the output unit status management unit 50 about printing failure due to an output unit failure, paper out, etc., as soon as the predicted processing time is input from the processing time prediction unit 4. The output unit status management unit 50 returns information such as printing failure or out of paper to the output unit recording speed selection unit 51. If printing of the output unit is possible, the output unit recording speed selection unit 51 returns to the processing time estimation unit 4. The recording speed of the output unit 6 is selected based on the predicted drawing processing time input from the.

The output unit recording speed selection unit 51 selects one of the recording speeds that can be selected in the output unit 6 based on the drawing processing prediction time for each band corresponding to the size of the band buffer memory input from the processing time prediction unit 4. Therefore, the recording speed is selected so that the drawing processing for each band is completed in time and print data is not lost. FIG. 11 is an explanatory diagram showing how the output unit recording speed selection unit 51 selects a recording speed. In FIG. 11, one page is divided into n bands,
The processing prediction time of each band is different. On the other hand, since the electrophotographic page printer of the present embodiment must be driven at a constant speed within at least one page, the printing time of each band is constant. Accordingly, in order to finish the drawing processing of the next band before the printing of each band is completed, in the present embodiment, the processing prediction time of the band having the longest processing prediction time (band 4 in FIG. 11) is set.
It is necessary to select a recording speed at which the printing time of one band becomes longer. The recording speed selected by the output unit recording speed selection unit 51 is notified to the output unit process control unit 52.

The output unit process control unit 52 controls the process of the output unit based on the recording speed selected by the output unit recording speed selection unit 51. The process control of the output unit process control unit includes control of the start timing of the output unit. The control of the start timing of the output unit 6 is performed based on the notification of the selected recording speed from the output unit recording speed selection unit 51, but according to the input of the print data to the print data input unit 2. May be done. In particular, the fixing device 67 which requires a long time to cycle up,
It is desirable to start the polygon mirror motor and the like of the semiconductor laser scanning device 61 at an early stage.

In the color page printer using the laser scanning type electrophotographic system of the present embodiment, the output unit 6 which must be controlled in accordance with the recording speed of the output unit 6 is variable.
In the printing process, the control target is the rotation speed of the photosensitive drum, the rotation speed of the transfer drum, the rotation speed of the fixing device, the rotation speed of the recording paper conveyance roller, the rotation speed of the polygon mirror of the semiconductor laser scanning device, and the rotation speed of the developing roll of the developing device. , Transfer current, cleaner brush rotation speed, and the like. Among these, the photoconductor drum rotation speed, the transfer drum rotation speed, the fixing device roll rotation speed, the recording paper conveyance roller rotation speed, the polygon mirror rotation speed of the semiconductor laser scanning device, the developing roller rotation speed of the developing device, and the cleaner brush rotation speed Is an object to be controlled in proportion to the recording speed. The transfer current may be controlled by setting the constant current source in proportion to the recording speed. In general, a brushless servomotor is used to drive a polygon mirror of a semiconductor laser scanning device, and a PLL (Phase Locked Loop) is used to stabilize its rotation speed.
p) Control is used. Therefore, the rotation speed of the polygon mirror can be changed by dividing the reference frequency of the PLL control.

As another method of changing the exposure scanning in accordance with the variable recording speed in the semiconductor laser scanning device, there is a method of thinning out the exposure scanning for printing at a video interface for a constant polygon mirror rotation speed. . According to this method, it is possible to set the recording speed to 1/2, 1/3, ..., 1 / m with respect to the maximum recording speed. In this method, although the selectable recording speed is reduced, it is not necessary to change the rotation speed of the polygon mirror motor of the semiconductor laser scanning device, which requires a long time for the cycle up, and the printing to the print data input unit 2 is performed as described above. It is possible to start at an early stage such as starting in response to data input.

Further, although different from the color page printer using the electrophotographic system of the laser scanning system of the present embodiment,
In a color page printer using an electrophotographic system of a solid-state scanning system such as an LED print head, it is only necessary to change the timing of each exposure scan. A solid-state scanning method such as an LED print head is suitable for the present invention because it does not require a cycle-up.

[0072]

As described above, according to the present invention, in a print processing apparatus in which a storage device for temporarily storing print data to be output by a page printer is constituted by a band memory, a drawing command group in a drawing processing unit is provided. From the drawing element data such as trapezoidal data, the processing time prediction unit predicts the drawing processing time for each band by the processing time prediction unit before drawing processing. The recording speed of the output unit is controlled. Therefore, it is possible to process the print data in accordance with the contents of the print data, and it is possible to prevent a decrease in image quality due to a mismatch between the processing performance of the drawing processing unit and the recording speed of the output unit. Further, it is possible to optimally process print data including a complicated graphic drawing command described in a description language which cannot be handled by the conventional method, according to the complexity of the print data.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of a print processing apparatus according to the present invention.

FIG. 2 is an explanatory diagram of a configuration of a color page printer according to the embodiment.

FIG. 3 is a block diagram illustrating a configuration example of a drawing processing unit.

FIG. 4 is a block diagram illustrating a configuration example of a drawing element data generation unit.

FIG. 5 is a diagram illustrating recursive division of a Bezier curve.

FIG. 6 is a diagram illustrating trapezoidal data.

FIG. 7 is a block diagram illustrating a configuration example of a processing time prediction unit.

FIG. 8 is a diagram illustrating division of trapezoidal data at a band boundary.

FIG. 9 is a flowchart illustrating an operation of a drawing time prediction unit.

FIG. 10 is a block diagram illustrating a configuration example of an output control unit.

FIG. 11 is an explanatory diagram showing how a recording speed is selected by an output unit recording speed selection unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print data creation part 2 Print data input part 3 Expansion processing part 30 Lexical analysis part 31 Drawing processing part 4 Processing time prediction part 5 Output control part 6 Output part

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuki Hirata 430 Nakai-cho, Nakai-cho, Ashigara-kami, Kanagawa Prefecture Inside Fuji Xerox Fuji Xerox Co., Ltd. (72) Inventor Masahiko Koyanagi 430 Nakai-cho, Ashigara-gun, Kanagawa Prefecture Green Tech Nakai Inside Fuji Xerox Co., Ltd.

Claims (8)

[Claims] 1. An input unit having at least one of a character, a figure, and an image and inputting print data described by a predetermined drawing command, an image output unit, and a type and an attribute of the drawing command. A drawing element generation unit for generating drawing element data representing a drawing area from the print data; and a drawing element data generated by the drawing element generation unit to be developed into a data structure that can be output by the image output unit. Drawing processing means; area decomposing means for decomposing the drawing element data generated by the drawing element generating means into a plurality of areas in a page; and for each of the areas, at least the drawing element data included in the area. Based on the sum of the estimated drawing time,
A drawing time prediction unit that predicts a drawing time of the region, and a control unit that determines an image output speed of the image output unit according to a drawing prediction time for each of the regions predicted by the drawing time prediction unit. A print processing apparatus, comprising: 2. The drawing time predicting means predicts by adding a processing time of the drawing element generating means, a processing time of the area decomposing means, and a predicted drawing time of the total drawing element data for each area. 2. The print processing apparatus according to claim 1, wherein 3. The print processing apparatus according to claim 1, wherein the drawing element data includes at least vector data indicating an area to be drawn and attribute information thereof. 4. The print processing apparatus according to claim 1, wherein the drawing time prediction means has a coefficient for obtaining a predicted drawing time of the drawing element data. 5. The image output means has a plurality of image output speeds, and the control means outputs a page at one of these output speeds based on the prediction time predicted by the drawing time prediction means. 5. The print processing apparatus according to 1, 2, 3, or 4, wherein the image output unit is controlled every time. 6. The print processing apparatus according to claim 1, wherein the drawing time predicting unit predicts a drawing time for each band obtained by dividing one page into a plurality of pages. 7. The printing process according to claim 1, wherein the drawing processing means performs the drawing process for the one page of the drawing command for each of a plurality of divided bands. apparatus. 8. The drawing time prediction means predicts the drawing exhibition prediction time for each of the bands, and
7. The print processing apparatus according to claim 6, wherein an image output speed of a speed lower than the longest predicted drawing time among the bands for the page is determined.