JP2006048215A - Method for improving picture quality of printing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that there is possibility that memory consumption for storing attribute information is increased, and a memory for rendering is running short in enlarging the storage area of attribute data. <P>SOLUTION: An image processing method different from normal line processing is used when thin wire processing is used so that the reproducibility of a thin wire can be improved, and that whether or not any identical color-designated graphic or line is made adjacent to the thin wire is decided, and when it is decided that any graphic or line is adjacent, the same image processing is carried out so that the reproducibility of the thin wire can be improved, and that any unnatural image formation can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a printing apparatus controlled by a printer controller connected to a host computer or another device, and in particular, attribute information is provided for each pixel of raster data generated according to a drawing command. The present invention relates to an image forming apparatus that can be added to improve print image quality.

  In a conventional attribute information addition method in an image forming apparatus, attribute information is added to each pixel of raster data generated according to a drawing command to improve the print image quality. On the other hand, when more advanced image processing is desired, it is necessary to expand the area for storing attribute information and store the information, which increases the memory consumption.

Further, when the attribute data storage area is expanded, the memory consumption for storing the attribute information increases, and there is a high possibility that the memory for rendering is insufficient. In order to avoid this, there is a problem that desired image quality may not be obtained by deleting attribute information and processing the entire page with the same attribute value. (Patent Document 1)
Japanese Patent Laid-Open No. 2003-143413

  In the attribute information adding method in the conventional image forming apparatus, attribute information is added to each pixel of raster data generated according to the drawing command to improve the print image quality, while more detailed image processing is desired. In this case, it is necessary to expand the area for storing the attribute information and store the information, which increases the memory consumption. Further, when the attribute data storage area is expanded, the memory consumption for storing the attribute information increases, and there is a high possibility that the memory for rendering is insufficient. In order to avoid this, there is a problem that desired image quality may not be obtained by deleting attribute information and processing the entire page with the same attribute value.

  The present invention has been made in view of the above problems, and provides an image forming apparatus capable of improving print image quality without increasing memory consumption by changing the meaning of attribute information according to the input data format. It is for the purpose.

  The printing apparatus of the present invention that achieves the above object has the following configuration.

  According to a first aspect of the present invention, there is provided an arc designation command included in the print data, a first arc dividing means for dividing the arc into a plurality of Bezier cubic curves according to the arc designation command, and the smoothness included in the print data. A linearizing means for performing linear approximation on the Bezier cubic curve divided by the first arc dividing means according to the above, and the straight line data generated by the straightening means or the arc information included in the arc designation command First arc information storing means stored above, arc information reading means for reading the first stored information held by the first arc information storing means, and read by the first arc information reading means Image formation having outline generation means for generating line edges in accordance with line width, connection type, and leading edge processing command included in the print data for the straight line data The broken line command determining means for determining whether or not a broken line pattern designation command is designated in the print data when the first arc dividing means is executed, and the broken line instruction judging means determines that the broken line processing is designated. In accordance with the arc dividing angle obtained by the dividing angle generating means, the dividing angle generating means for obtaining the arc dividing angle based on the broken line pattern included in the print data and the arc length obtained from the arc designation command. A second arc dividing means for dividing the arc into a plurality of arcs and dividing it into a Bezier cubic curve; a second arc information storing means for storing the Bezier cubic curve generated by the second arc dividing means on the storage device; It is to have established.

  A second invention according to the present invention is a first arc information reading means for reading arc information held by the first arc information storage means when a fill is designated in response to an arc designation command included in print data. And a fill area generating means for generating a fill area using the arc information read out by the first arc information reading means, and when the line drawing is specified in response to the arc specifying command included in the print data, Arc information registration determining means for determining whether or not the arc information is held by the arc information storing means, and the arc information stored in the second arc information storing means is held by the arc information registration determining means. When it is determined that the arc information stored in the second arc information storage means is read, it is determined that the arc information is not registered. A second arc information reading means for reading the arc information stored by the first arc information storage means, and generating a line area using the arc information read by the second arc information reading means. An outline generation means is provided.

  The third invention according to the present invention is to determine whether or not to use the second arc dividing means, the arc storing means, and the arc reading means when it is determined that the broken line processing is designated by the broken line command determining means. Arc division method selection means for determining the

  According to a fourth aspect of the present invention, a determination condition for determining whether or not to use the second arc dividing means, the arc storing means, and the arc reading means in the arc dividing method selecting means is stored in a storage device in the apparatus. The arc division method determination condition storage means is provided.

  According to a fifth aspect of the present invention, it is possible to include the arc division method determination condition in the print data.

  A sixth invention according to the present invention is that it is possible to set the arc division method determination condition via an external connection device.

  According to a seventh aspect of the present invention, there is provided a multi-user setting storage means for storing the arc division method determination condition for each user who uses the image forming apparatus.

  According to an eighth aspect of the present invention, there is provided a plurality of PDL setting storage means for setting and storing the arc division method determination condition for each PDL (printer description language) that can be processed by the image forming apparatus.

  According to a ninth aspect of the present invention, there is provided an arc dividing condition setting determining means for determining whether or not the arc dividing method determining condition is set when line drawing is specified in response to an arc specifying command included in the print data. And arc information registration determining means for determining whether or not arc information is held by the second arc information storage means when it is determined that the arc dividing condition is set in the arc dividing condition setting determining means And when the arc information stored in the second arc information storage means is held by the arc information registration determination means, the arc information stored in the second arc information storage means is read out. 2 arc information reading means, and outline generating means for generating a line area using the arc information read by the second arc information reading means, When the arc information is not registered by the arc information registration determining means or the arc information dividing condition setting determining means determines that the arc dividing condition is not set, the arc information is read by the first arc information reading means. Further, a broken line command determination unit that determines whether or not a broken line pattern designation command is designated in the print data, and the designation is performed when it is determined by the broken line command determination unit that the broken line processing is designated. A broken line cutting means for cutting the first arc information to a specified broken line length according to the broken line pattern, and generating line edges according to the line width, connection type, and tip processing command for the straight line data cut by the broken line cutting means. An outline generation means is provided.

(Function)
In this configuration, means for changing the meaning of the attribute information storage area according to the input data format, means for adding attribute information to each pixel of the raster data generated according to the drawing command, and input data when executing image processing By interpreting the meaning of the attribute information added to the raster data in accordance with the format and providing means for selecting an optimal image processing method, it is possible to improve the print image quality without increasing the memory consumption.

  As described above, according to the present invention, the means for changing the meaning of the attribute information storage area according to the input data format, and the means for adding the attribute information to each pixel of the raster data generated according to the drawing command And interpreting the meaning of the attribute information added to the raster data according to the input data format when executing image processing, and providing a means to select the optimal image processing method, improving print image quality without increasing memory consumption Can be achieved.

  First, a configuration example of a laser beam printer will be described as an example of an output device to which the embodiment of the present invention can be applied. The present embodiment can be applied not only to a laser beam printer but also to other types of output devices such as an ink jet printer and an MFP (Multi Function Printer).

  FIG. 1 is a block diagram showing the configuration of a laser beam printer as a first embodiment of the printing apparatus of the present invention, FIG. 2 is a diagram schematically showing the mechanism of the laser beam printer in FIG. 1, and FIG. FIG. 2 is a block diagram illustrating a configuration of a printer controller mounted on the laser beam printer 1.

  In FIG. 1, a data processing device 101 is, for example, a computer, and functions as a supply source of image information or a control device for a printer. In this embodiment, a laser beam printer (printer) is used as the image recording apparatus 102.

  The printer controller 103 generates bitmap data for each page based on the image information (for example, ESC code, page description language, etc.) supplied from the data processing apparatus 101 and sends it to the printer engine 105.

  The printer engine 105 forms a latent image on the photosensitive drum based on the bitmap data supplied from the printer controller 103, and transfers and fixes the latent image on the recording medium (electrophotographic method). Record.

  The panel unit 104 is used as a user interface. The user can instruct a desired operation by operating the panel unit 104. The panel unit 104 displays processing contents of the printer 102 and warning contents for the user.

  Next, the configuration of the laser beam printer taken up as an example of the embodiment in this example will be described with reference to FIG.

  FIG. 2 is a cross-sectional view illustrating the configuration of the tandem color printer 102.

  In the figure, 201 is a printer housing. 202 is an operation panel provided with a switch for giving various instructions by the user, an LED display or an LCD display for displaying a message, printer setting contents, and the like. It is one mode. Reference numeral 203 denotes a board accommodating portion that accommodates boards constituting the electronic circuit portions of the video controller 103 and the printer engine 105.

  A paper cassette 220 holds the paper (recording medium) S and has a mechanism for electrically detecting the paper size by a partition plate (not shown). Reference numeral 221 denotes a cassette clutch which takes out the uppermost sheet S of the paper S placed on the paper cassette 220 and feeds the taken paper S by a driving force transmitted from driving means (not shown). It has a cam that conveys up to. This cam rotates intermittently each time paper is fed, and feeds one sheet S corresponding to one rotation. Reference numeral 223 denotes a paper detection sensor that detects the amount of paper S held in each paper cassette 220.

  The paper feed roller 222 is a roller that conveys the leading edge of the paper S to the registration shutter 224. Reference numeral 224 denotes a registration shutter that can stop paper feeding by pressing the paper S.

  230 is a manual feed tray, and 231 is a manual paper feed clutch. The manual sheet feeding clutch 231 is used to convey the leading edge of the sheet S to the manual sheet feeding roller 232, and the manual sheet feeding roller 232 is used to convey the leading edge of the sheet S to the registration shutter 224. The paper S to be used for image recording is fed by selecting one of the paper cassette 220 and the manual feed tray 230.

  The printer engine 105 communicates with the video controller 103 in accordance with a predetermined communication protocol, selects one of the paper cassettes 220 from the manual feed tray 230 in accordance with an instruction from the video controller unit 103, and starts printing. In response to the instruction, the sheet S is conveyed from the corresponding sheet feeding means to the registration shutter 224. The printer engine 105 includes a paper feeding unit, a mechanism related to an electrophotographic process such as formation, transfer, and fixing of a latent image, a paper discharge unit, and a control unit thereof.

  204a, 204b, 204c, and 204d are image recording units having photosensitive drums 205a, 205b, 205c, and 205d, a toner holding unit, and the like, and form a toner image on the sheet S by an electrophotographic process. On the other hand, 206a, 206b, 206c, and 206d are laser scanner units that supply image information by a laser beam to the image recording unit.

  In the image recording units 204a, 204b, 204c, and 204d, a paper transport belt 250 that transports the paper S is stretched flat in the paper transport direction (from the bottom to the top in the figure) by a plurality of rotating rollers 251-254. In the most upstream area, the sheet is electrostatically attracted to the sheet conveying belt 250 by the attracting roller 225 to which a bias is applied. Further, four photosensitive drums 205a, 205b, 205c, and 205d are arranged in a straight line so as to face the belt conveyance surface, and constitute an image forming unit. In each of the image recording units 204a, 204b, 204c, and 204d, a charger and a developing device are disposed so as to sequentially surround the vicinity of the periphery of the photosensitive drum.

  In the laser scanner units 206a, 206b, 206c, and 206d, 207a, 207b, 207c, and 207d are laser units that drive a built-in semiconductor laser in accordance with an image signal (/ VIDEO signal) sent from the printer controller 103. And fire a laser beam. Laser beams emitted from the laser units 207a, 207b, 207c, and 207d are scanned by polygon mirrors (rotating polygon mirrors) 208a, 208b, 208c, and 208d to form latent images on the photosensitive drums 205a, 205b, 205c, and 205d. To do.

  A fixing device 260 fixes the toner image formed on the paper S by the image recording units 204a, 204b, 204c, and 204d to the recording paper S by heat. A conveyance roller 261 discharges and conveys the paper S. A paper discharge sensor 262 detects a paper discharge state of the paper S. Reference numeral 263 denotes a paper discharge roller and double-sided printing conveyance path switching roller, which conveys the paper S in the paper ejection direction. If the paper S conveyance instruction is paper discharge, the paper S is discharged directly to the paper discharge tray 264. In the case of double-sided conveyance, immediately after the trailing edge of the paper S passes the paper discharge sensor 262, the rotation direction is changed to the reverse direction, and the paper S is conveyed to the double-sided printing conveyance path 270 by switching back. A sheet discharge amount detection sensor 265 detects the amount of sheets S stacked on the sheet discharge tray 264.

  Reference numeral 270 denotes a conveyance path for double-sided printing. The sheet S conveyed for duplex printing by the discharge roller / double-sided conveyance path switching roller 263 is conveyed again to the registration shutter 224 by the duplex conveyance rollers 271 to 274. It waits for a conveyance instruction to the image recording units 204a, 204b, 204c, and 204d.

  The printer 102 can be further equipped with optional units such as an optional cassette and an envelope feeder.

  Next, the configuration of the printer controller 103 will be described with reference to FIG.

  The printer controller 103 includes an input buffer (not shown) for inputting print data sent from the data processing apparatus 101 and settings for instructing the operation of the apparatus, and an output including a signal sent to the data processing apparatus 101 and device information data. A host I / F unit 302 provided with an output buffer (not shown) for temporarily storing data, and the host I / F unit 302 is configured to transmit signals to and from the data processing device 101; The communication packet input / output unit is configured, and communication control with the data processing apparatus 101 is performed.

  The print data input via the host I / F unit 302 is given to the image data generation unit 303. The image data generation unit 303 analyzes input print data based on a predetermined analysis means (for example, PDL analysis processing), generates an intermediate language drawing object from the analysis result, and can be further processed by the printer engine 105 Bitmap data generation is performed. Specifically, print data is analyzed and object information is created by the analysis, and rasterization processing is performed in parallel with the creation of the object information. In this rasterization process, the display color RGB (additive color mixture) included in the print data is converted to YMCK (subtractive color mixture) that can be processed by the printer engine, the bit pattern and outline stored in advance from the character code included in the print data Performs conversion to font data such as fonts, creates bitmap data in page units or band units, applies pseudo-gradation processing using a dither pattern to the bitmap data, and allows printing processing in the printer engine Generate bitmap data.

  The created bitmap data is stored in the image memory 305. Reading of the bitmap data stored in the image memory 305 is controlled by the DMA control unit 308, and the control for reading the bitmap data from the image memory 305 by the DMA control unit 308 is performed based on an instruction from the CPU 309.

  Bitmap data read from the image memory 305 is transferred to the engine 105 as a video signal via the engine I / F unit 306. The engine I / F unit 306 includes an output buffer (not shown) that temporarily holds a video signal transferred to the engine 105 and an input buffer (not shown) that temporarily holds a signal sent from the engine 105. The engine I / F unit 306 constitutes an input / output unit for signals exchanged with the engine 105 and controls communication with the engine 105.

Instructions relating to mode setting and the like issued by operation input from the panel unit 104 (shown in FIG. 1) are input via the panel I / F unit 301. The panel I / F unit 301 is connected between the panel unit 104 and the CPU 309. Configure the interface. (Instructions to the printing device, such as mode setting, issued by operation input can also be instructed via the host I / F unit 302 that performs two-way communication with external devices.)
The CPU 309 controls each block described above according to the mode instructed from the panel unit 104 or the data processing apparatus 101, and this control is executed based on a control program stored in the ROM 304. The control program stored in the ROM 304 is an OS (operating system) for performing time-sharing control in units of load modules called tasks by the system clock, and a plurality of load modules that are controlled by the OS in units of functions. It consists of. The control program including this load module is stored in an EEPROM (nonvolatile memory) 310 as necessary.

  A RAM 307 is used as a work area for arithmetic processing by the CPU 309. Each block including the CPU 309 is connected to the system bus 320. The system bus 320 includes an address bus and a system bus.

  Next, the processing path of input data in the printer controller of FIG. 3 is shown for each functional block with reference to FIG.

  Print data input from the external connection device through the host interface unit (302) is command-analyzed by the PDL analysis unit (303a), and then generated as a drawing object (intermediate language) by the drawing object generation unit (303b). It is temporarily recorded in the upper working memory (307).

  Then, the drawing memory is read from the working memory on the RAM as needed and rasterized (303c), and finally the image data recorded on the recording medium is developed into a bitmap image and stored in the image memory (305). 306) and recording on a recording medium is performed.

  In the printer control system configured as described above, FIGS. 5, 6, 7 and 8 are flowcharts showing programs stored in the program ROM indicated by 304 in FIG.

  First, as a conventional example, an arc drawing process in a conventional image forming apparatus will be described with reference to FIGS. 5, 6, 7, and 8. FIG.

(Conventional example 1)
If the print data input via the host interface and analyzed by the PDL analysis unit contains an arc designation command, a predetermined set value required for arc drawing from the designated arc designation command (for example, arc drawing start angle / (End angle / radius / drawing direction, etc.) is read (501), arc data is divided into a plurality of Bezier cubic curves (502) from the various setting values that have been read, and a Bezier cubic curve divided in 502 is formed. Point sequence (control point) information to be generated is generated and saved (503) in the storage area.

  After that, when an arc drawing command is specified, the point sequence (control point) information constituting the Bezier cubic curve stored in 503 is read (601), and the smoothness used in the linearization approximation process is referenced (602). A straight line approximation process is executed on the arc according to the smoothness referenced in 602 (603). Next, it is determined whether the drawing processing command specified in the print data is a line drawing command or a graphic area filling command (604). If it is determined that the drawing processing command is a graphic area filling command, the linear component generated in 603 is determined. Bitmap data generation processing is performed on the closed region surrounded by (609), and the arc drawing processing is terminated. On the other hand, if it is determined that line drawing is performed at 604, reference is made to setting values necessary for line drawing (for example, line width / tip shape / connection shape / broken line component) (605), and for line drawing referenced at 605 It is determined whether or not broken line information is specified in the setting (606). If broken line information is not specified, outline data generation processing is performed according to the line drawing setting referenced in 605 for the straight line component generated in 603. (608) When the broken line information is specified, the broken line component is cut out from the straight line component generated in 603 according to the length of the straight line and the broken line length specified in the broken line information (607) Further, outline data generation processing is executed for the broken line component cut out at 607 in accordance with the line drawing setting referred to at 605 (608), and bitmap data generation processing is performed for the closed region surrounded by the straight line component generated at 608. Perform (609), arc drawing The process is terminated.

(Conventional example 2)
If the print data input via the host interface and analyzed by the PDL analysis unit contains an arc designation command, a predetermined set value required for arc drawing from the designated arc designation command (for example, arc drawing start angle / The end angle / radius / drawing direction, etc.) are read (701), and the arc information read by 701 is stored in the storage area (702).

  Thereafter, when an arc drawing command is designated, the arc information stored in 702 is read (801), and it is determined whether the drawing processing command designated in the print data is a line drawing command or a graphic area filling command ( 801), if it is determined that the command is a graphic area filling command, refer to the smoothness used in the linearization approximation process (803), and execute the linear approximation process on the arc according to the smoothness referred to in 803 (804). , 804, the bitmap data generation process is performed on the closed region surrounded by the straight line component generated in step 804 (812), and the arc drawing process ends.

  On the other hand, if it is determined that line drawing is performed in 802, refer to the setting values required for line drawing (for example, line width / tip shape / connection shape / broken line component) (805), and for line drawing referenced in 805 It is determined whether or not the broken line information is specified in the setting (806), and when it is determined that the broken line information is not specified, the smoothness used in the linear approximation process is referred to (809) and 809. The straight line approximation process is executed for the arc according to the smoothness (810), and the outline data generation process is executed for the straight line component generated at 810 according to the line drawing settings referenced at 805 (811) and generated at 811 Bit map data generation processing is performed on the closed region surrounded by the straight line component (812), and the arc drawing processing is terminated.

  Further, if it is determined that the broken line information is specified in 806, the broken line pattern is calculated from the length of the circular arc obtained from the given circular arc information request and the length of the broken line pattern included in the line drawing processing setting referenced in 805. A cut-out angle for each is generated (807), and the arc data is divided into a plurality of Bezier cubic curves according to the angle and arc information cut out in 807 (808), and further, a Bezier cubic curve generated in 808 is formed. Generate point sequence (control point) information. Next, refer to the smoothness used in the linearization approximation process for the Bezier cubic curve (809), execute the linear approximation process for the arc according to the smoothness referenced in 809 (810), and the linear component generated in 810 The outline data generation process is executed in accordance with the line drawing setting referenced in 805 (811), the bitmap data generation process is performed on the closed region surrounded by the linear component generated in 811 (812), and the arc The drawing process is terminated.

  In the conventional printing apparatus, as shown in the above conventional example, a broken line command is executed after dividing into a Bezier cubic curve or registering it in a memory as arc data in accordance with a given arc designation command and performing a linearization process when executing an arc drawing process. Accordingly, the broken line component is cut out and the outline generation process is performed. Or, because the broken line cut angle was obtained from the broken line component specified when executing the arc drawing process and the circumference obtained by the arc specifying command, it was divided into Bezier cubic curves and the outline generation process was performed, so the fill command for the same arc specification When the broken line drawing command is repeatedly executed, wasteful processing efficiency may occur.

  This point has been improved in Figs. 9, 10, 11, 12, and 13. The first arc data given by the PDL, the length of the arc and the length of the broken line component when drawing the arc specified by the broken line Saves two types of arc data, the second arc data obtained by cutting out the arc for broken line drawing according to the angle determined from the above, and the drawing processing command for the graphic data designated by the arc designation command is a paint command or broken line drawing This is a method of improving arc drawing processing efficiency by enabling switching at any time depending on the command.

  Embodiments will be described below with reference to FIGS. 9, 10, 11, 12, and 13.

  Note that the processing inside the printing apparatus in this case is given as an example, and it is not always necessary to perform these operations.

  Figures 9 and 10 improve the above problems, and the second arc in which a broken line drawing arc is cut out according to the first arc data given by the PDL and the angle obtained from the length of the arc and the length of the broken line component. Two types of arc data are saved and can be used at any time depending on whether the drawing processing command for the graphic data specified by the arc specification command is a paint command or a broken line drawing command, improving the arc drawing processing efficiency The method of doing is shown in the flowchart.

  If the print data input via the host interface and analyzed by the PDL analysis unit contains an arc designation command, a predetermined set value required for arc drawing from the designated arc designation command (for example, arc drawing start angle / (End angle / Radius / Drawing direction, etc.) is read (901), arc data is divided into multiple Bezier cubic curves (902) from the various read values, and a Bezier cubic curve divided in 902 is constructed. Point sequence (control point) information to be generated is generated and saved (903) in the storage area. Next, reference is made to setting values required for line drawing (eg, line width / tip shape / connection shape / broken line component) (904), and whether or not broken line information is specified in the line drawing settings referenced in 904. (905), and if it is determined that the broken line information is not specified, the arc specifying process is terminated. On the other hand, if it is determined in 905 that the broken line information is designated, each broken line pattern is calculated based on the arc length obtained from the given arc information request and the broken line pattern length included in the line drawing processing setting referred to in 904. (906), and the arc data is divided into a plurality of Bezier cubic curves according to the angle and arc information cut out in 906, and the sequence of points (control points) constituting the divided and generated Bezier cubic curves ) Information is generated (907) and stored in the storage area (908). FIG. 4 shows an example of a broken line pattern referred to at this time and an example of an arc to be cut out. Further, the cutout angle Θn generated in 906 is assumed that the radius = r, the length of the broken line component = ln, the drawing start angle = δ, and the drawing end angle = γ (hereinafter, n is the number of designated broken line components).

として求められ、それぞれの切り出し角度に従い切り出されたベジェ3次曲線の開始角度δnと終了角度γnは

The start angle δn and the end angle γn of the Bezier cubic curve cut out according to each cutout angle are

で求めることができ、n=1の場合は

If n = 1,

となる。

It becomes.

  After that, when an arc drawing command is specified, it is determined whether the drawing processing command specified in the print data is a line drawing command or a graphics area filling command (1001), and is determined to be a graphics area filling command. In this case, the point sequence information constituting the first Bezier cubic curve divided and stored in 903 is read (1002), the smoothness used in the linear approximation process is referenced (1003), and the arc is determined according to the smoothness referenced in 1003. After executing the straight line approximation process (1004), the bitmap data generation process is performed on the closed region surrounded by the straight line component generated in 1004 (1017), and the arc drawing process is terminated.

  On the other hand, if 1001 is determined to be line drawing, refer to the setting values required for line drawing (for example, line width / tip shape / connection shape / broken line component) (1005), and for line drawing referenced in 1005 It is determined whether or not the broken line information is specified in the setting (1006). If it is determined that the broken line information is not specified, the point sequence information constituting the first Bezier cubic curve stored and divided in 903 (1007), refer to the smoothness used in the linear approximation process (1014), execute the linear approximation process on the arc according to the smoothness referenced in 1014 (1015), and convert the linear component generated in 1015 to On the other hand, outline data generation processing is executed according to the line drawing settings referenced in 1005 (1016), bitmap data generation processing is performed on the closed region surrounded by the straight line component generated in 1016 (1017), and arc drawing is performed. The process ends.

  Further, if it is determined in 1006 that the broken line information is specified, it is determined whether there is a second Bezier cubic curve stored in 908 (1008). In 1008, the second Bezier cubic curve is determined. If it is determined that there is, read the second Bezier cubic curve stored in 908 (1013), refer to the smoothness used during the linear approximation process (1014), and follow the smoothness referenced in 1014 for the arc After executing the straight line approximation process (1015), execute the outline data generation process according to the line drawing settings referenced in 1005 for the straight line component generated in 1015 (1016) and surround it with the straight line component generated in 1016 Bit map data generation processing is performed on the closed region to be processed (1017), and the arc drawing processing is terminated.

  On the other hand, if it is determined in 1008 that there is no second Bezier cubic curve, the first Bezier cubic curve stored in 903 is read (1009), and the smoothness used in the linear approximation process is referenced (1010). After executing the straight line approximation process on the arc according to the smoothness referenced in 1010 (1011), the broken line according to the length of the straight line component and the length of the broken line specified in the broken line information for the straight line component generated in 1011 Performs component cutout processing (1012), executes outline data generation processing according to the line drawing settings referenced in 1005 for the linear components regenerated in 1012 (1016), and is surrounded by the linear components generated in 1016 Bitmap data generation processing is performed on the closed region (1017), and the arc drawing processing is terminated.

  As described above, the arc data is divided and stored into Bezier cubic curves in the arc designation process, and if a broken line pattern has been registered, the arc is cut and saved in advance in a Bezier cubic curve for each broken line pattern. It is possible to improve the arc drawing processing efficiency when a drawing command is specified.

  In the first embodiment, the arc data is divided and stored into a Bezier cubic curve in the arc designation process, and when a broken line pattern is designated, the method is previously cut out and saved in a Bezier cubic curve for each broken line pattern. As described above, in the present embodiment, a method will be described in which the input arc data is stored as it is, and when a broken line pattern is designated, it is cut out and stored in a Bezier cubic curve for each broken line pattern. FIGS. 11 and 12 are flowcharts showing a method of arc drawing processing in this embodiment.

  If the print data input via the host interface and analyzed by the PDL analysis unit contains an arc designation command, a predetermined set value required for arc drawing from the designated arc designation command (for example, arc drawing start angle / (End angle / radius / drawing direction, etc.) are read (1101), and the read various setting values are stored (1102). Next, refer to the setting values required for line drawing (for example, line width / tip shape / connection shape / broken line component) (1103), and whether or not broken line information is specified in the line drawing settings referenced in 1103 (1104), and when it is determined that the broken line information is not specified, the arc specifying process is terminated. On the other hand, if it is determined in 1104 that the broken line information is specified, each broken line pattern is calculated based on the arc length obtained from the given arc information request and the broken line pattern length included in the line drawing processing setting referenced in 1103. (1105), and a sequence of points (control points) constituting the segmented Bezier cubic curve by dividing the arc data into a plurality of Bezier cubic curves according to the angle and arc information cut out in 1105 ) Information is generated (1106) and stored in the storage area (1107). At this time, the cut-out angle Θn generated in 1105 is obtained using the same calculation formula as in the first embodiment.

  After that, when an arc drawing command is specified, it is determined whether the drawing processing command specified in the print data is a line drawing command or a graphics area filling command (1201), and is determined to be a graphics area filling command. In this case, the information necessary for drawing the arc saved in 1102 is read out (1202), divided into a plurality of Bezier cubic curves (1203), and the smoothness used in the linear approximation process is also referred to (1204) and is referenced in 1204 After executing the straight line approximation process on the arc in accordance with the smoothness (1205), the bitmap data generation process is performed on the closed region surrounded by the straight line component generated in 1205 (1218), and the arc drawing process is terminated.

  On the other hand, if it is determined in 1201 that the line drawing is performed, the setting values necessary for line drawing (for example, line width / tip shape / connection shape / broken line component) are referred to (1206) and for line drawing referred to in 1206 It is determined whether or not the broken line information is specified in the setting (1207), and when it is determined that the broken line information is not specified, the information necessary for the arc drawing stored in 1102 is read (1208) Divide into Bezier cubic curves (1209), refer to the smoothness used during linear approximation (1215), perform straight line approximation on the arc according to the smoothness referenced in 1215 (1216), and generate in 1216 The outline data generation process is executed on the straight line component in accordance with the line drawing setting referenced in 1206 (1217), and the bitmap data generation process is executed on the closed region surrounded by the straight line element generated in 1217 ( 1218), the arc drawing process is terminated.

  If it is determined that the broken line information is specified in 1207, it is determined whether there is a Bezier cubic curve stored in 1107 (1210). If it is determined in 1210 that there is a Bezier cubic curve Reads the Bezier cubic curve stored in 1107 (1214), refers to the smoothness used during the linear approximation process (1215), and executes the linear approximation process on the arc according to the smoothness referenced in 1215 (1216) ), Execute outline data generation processing according to the line drawing settings referenced in 1206 for the straight line component generated in 1216 (1217), and bitmap data for the closed region surrounded by the straight line component generated in 1217 A generation process is performed (1218), and the arc drawing process is terminated.

  On the other hand, if it is determined in 1210 that there is no Bezier cubic curve, the information necessary for drawing the arc stored in 1102 is read (1211), and the arc length obtained from the read arc information request and referenced in 1206 A cut angle for each broken line pattern is generated from the length of the broken line pattern included in the line drawing processing setting (1212), and the arc data is divided into a plurality of Bezier cubic curves according to the angle cut in 1212 and the arc information. Generates the point sequence (control point) information that composes the segmented Bezier cubic curve (1213), refers to the smoothness used during the linearization approximation process (1215), and applies to the arc according to the smoothness referenced in 1215 After executing the line approximation process (1216), the outline data generation process is executed for the line component generated in 1216 according to the line drawing settings referenced in 1206 (1217) and surrounded by the line component generated in 1217 Closed Performs bit map data generating process with respect to frequency (1218), and terminates the arc rendering process.

  As described above, when arc data is saved and a broken line pattern has been registered in the arc designation process, the arc at the time of the arc drawing command is designated by cutting out and saving in advance a Bezier cubic curve for each broken line pattern. It is possible to improve the drawing processing efficiency.

  In Examples 1 and 2 above, a Bezier cubic curve for drawing a broken line is extracted from the length of the arc and the length of the broken line pattern according to whether the arc designation command is specified in the print data and whether there is a broken line pattern, and a control point is generated and saved. However, as shown in the flowchart of FIG. 13, not only the presence or absence of a broken line pattern but also whether or not to cut out a Bezier cubic curve for drawing a broken line can be set to improve processing efficiency. It is possible to improve the memory use efficiency.

  If the print data input via the host interface and analyzed by the PDL analysis unit contains an arc designation command, a predetermined set value required for arc drawing from the designated arc designation command (for example, arc drawing start angle / (End angle / radius / drawing direction, etc.) is read (1301), arc data is divided into multiple Bezier cubic curves (1302) from the various settings that have been read, and a Bezier cubic curve is further divided at 1302 Point sequence (control point) information to be generated is generated and stored in a storage area (1303). Next, refer to the setting values required for line drawing (for example, line width / tip shape / connection shape / broken line component) (1304), and whether or not broken line information is specified in the line drawing settings referenced in 1304 (1305), and when it is determined that the broken line information is not specified, the arc specifying process is terminated. On the other hand, if it is determined in 1305 that the broken line information is designated, it is determined whether or not to execute the broken line component cut-out process with reference to the designation of whether or not the broken line component included in the print data is cut (1306). ). If it is determined in 1306 that the broken line cutout process is not performed, the arc designation process is terminated. If it is determined that the broken line cutout process is performed, the arc length obtained from the arc information included in the print data and the line referenced in 1304 Generates a cut-out angle for each broken line pattern from the length of the broken line pattern included in the drawing processing setting (1307), and divides the arc data into a plurality of Bezier cubic curves according to the angle cut out in 1307 and the arc information. Point sequence (control point) information constituting the generated Bezier cubic curve is generated (1308) and stored in the storage area (1309). At this time, the cut-out angle Θn generated in 1105 is obtained using the same calculation formula as in the first embodiment.

  In the third embodiment, the print data specifies whether or not the broken line component is cut out and stored in the arc designation process. However, the arc division number is obtained from the arc length and the broken line pattern length. The broken line component cut-out process may be performed only when the number of divisions is smaller than a certain threshold.

  In Example 3 above, the designation of whether to cut out and save the broken line component in the arc designation process is included in the print data. However, the total length of the broken line components registered in the broken line pattern is designated. If the radius is shorter than the radius of the arc (which may be a diameter), it may be determined that the number of arc divisions will increase, and the broken line component cutout process may not be performed.

  In the third embodiment, it is assumed that the designation of whether or not the broken line component is cut out and stored in the arc designation process is included in the print data. However, the length of one of the broken line components registered in the broken line pattern is The broken line component cut-out process may be performed only when the arc is longer than a length obtained by dividing a certain number of arcs.

1 is a block diagram showing a configuration of a laser beam printer as a first embodiment of a printing apparatus according to the present invention. FIG. 2 is a diagram schematically showing the mechanism of the laser beam printer of FIG. FIG. 2 is a block diagram showing a configuration of a printer controller mounted on the laser beam printer of FIG. FIG. 4 is a diagram showing input data processing in the printer controller of FIG. 3 for each functional block. 9 is a flowchart showing arc registration designation processing in Conventional Example 1. 9 is a flowchart showing an arc drawing process in Conventional Example 1. 9 is a flowchart showing arc registration designation processing in Conventional Example 2. 10 is a flowchart showing arc drawing processing in Conventional Example 2. 3 is a flowchart showing arc registration designation processing in Embodiment 1 of the present invention. 3 is a flowchart showing an arc drawing process in Embodiment 1 of the present invention. 9 is a flowchart showing arc registration designation processing in Embodiment 2 of the present invention. 9 is a flowchart showing arc drawing processing in Embodiment 2 of the present invention. 9 is a flowchart showing arc registration designation processing in Embodiment 2 of the present invention. An example of the arc drawing process in Example 1 and Example 2 of the present invention.

Explanation of symbols

101 Data processor
102 Image recording device
103 Printer controller
104 Panel section
105 Printer engine
201 Printer housing
202 Operation panel
203 Board compartment
204a, 204b, 204c, 204d Image recording unit
205a, 205b, 205c, 205d Photosensitive drum
206a, 206b, 206c, 206d Laser scanner
207a, 207b, 207c, 207d Laser unit
208a, 208b, 208c, 208d Polygon mirror (Rotating polygon mirror)
220 Paper cassette
221 cassette clutch
222 Feed roller
223 Paper detection sensor
224 resist shutter
225 Suction roller
230 Bypass tray
231 Manual feed clutch
322 Manual feed roller
250 Paper conveyor belt
251 to 254 Rotating roller
260 Fuser
261 Transport roller
262 Output sensor
263 Discharge roller and transport path switching roller for duplex printing
264 Output tray
265 Output load detection sensor
270 Transport path for duplex printing
271 to 274 Double-sided transport rollers
301 Panel I / F section
302 Host I / F section
303 Image data generator
304 ROM
305 Image memory
306 Engine I / F part
307 RAM
308 DMA controller
309 CPU
310 EEPROM
311 hard disk
320 CPU bus

Claims (11)

  An image forming apparatus that generates print objects by analyzing print data based on a plurality of page description languages. In an image forming apparatus capable of processing a plurality of input formats, an input data format determining unit that determines an input data format; Image area signal defining means for changing the definition of the image area signal according to the input drawing command and the input data format, raster generating means for generating a raster image from the input drawing command, the drawing command and the input data format Accordingly, an image area signal adding means for generating and adding an image area signal for each pixel of the raster image, and an image processing method determination for determining an image processing method according to the image area signal definition defined by the image area signal defining means. And image processing means for performing image processing determined by the image processing method determining means An image forming apparatus, comprising.   The data format determined by the input data format determination means is a color space, and whether or not the area of the image area signal defined based on the result of the input data format determination is guaranteed to be gray is explicitly changed by the user. The image forming apparatus according to claim 1, wherein a meaning is given to whether or not processing is designated.   The arc dividing method selecting means for determining whether or not to use the second arc dividing means, the arc storing means, and the arc reading means when it is determined that the broken line processing is designated by the broken line command determining means. The image forming apparatus according to claim 1, further comprising:   The arc division method selection means has arc division method determination condition storage means for storing a determination condition for determining whether or not to use second arc division means, arc storage means, and arc reading means in a storage device in the apparatus. The image forming apparatus according to claim 1, wherein:   The image forming apparatus according to claim 1, wherein the arc division method determination condition can be included in print data.   The image forming apparatus according to claim 1, wherein the arc division method determination condition can be set via an external connection device.   7. The image forming apparatus according to claim 1, further comprising a plurality of user setting storage means for storing the arc dividing method determination condition for each user who uses the image forming apparatus.   8. The image forming apparatus according to claim 1, further comprising a plurality of PDL setting storage means for setting and storing the arc division method determination condition for each PDL (printer description language) that can be processed by the image forming apparatus.   In the arc division condition setting determination means for determining whether or not the arc division method determination condition is set when line drawing is specified in response to the arc designation command included in the print data, the arc division condition setting determination means When it is determined that an arc division condition is set, an arc information registration determination unit that determines whether or not arc information is held by the second arc information storage unit, and the arc information registration determination unit determines the arc information registration determination unit. Second arc information reading means for reading arc information stored by the second arc information storage means when it is determined that the arc information stored in the second arc information storage means is held; An outline generation means for generating a line area using the arc information read out by the arc information reading means of the second arc information reading means; When the arc information is not registered by the step or the arc information dividing condition setting determining means determines that the arc dividing condition is not set, the arc information is read by the first arc information reading means, and the print data A broken line instruction determining means for determining whether or not a broken line pattern designation instruction is designated, and a first operation according to the designated broken line pattern when the broken line instruction judging means determines that the broken line processing is designated. A broken line cutting means for cutting the arc information into a specified broken line length, and an outline generating means for generating line edges according to the line width, connection type, and tip processing command for the straight line data cut by the broken line cutting means The image forming apparatus according to claim 1, further comprising:   10. A bitmap generation unit that generates a bitmap image according to outline data generated by the outline generation unit or the linearization processing unit, and an output unit that outputs the bitmap image. Image forming apparatus.   The image forming apparatus according to claim 10, wherein the output unit is a printing apparatus.

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