JP2005238556A - Image forming apparatus, and image formation control program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a recording speed which exceeds the recording performance of a recording head. <P>SOLUTION: A plurality of the recording heads (201Bk-204Bk) of the same color are arranged at right angles to a transfer direction of a recording medium. A divide image forming means is set, which dividedly forms image data of the same color by the plurality of recording heads. The divide image forming means forms an image by assigning the image data of the same color to the plurality of heads one by one for each raster. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and an image forming control program for conveying and recording a recording medium which is a continuous sheet such as a mount and a label or tag sheet.

In general, in an image forming apparatus that transports a recording medium, which is a continuous sheet such as a backing sheet and a label or tag sheet, and performs recording, the image data is color-separated according to the number of recording heads, and each color (recording head) Image data is stored in each continuous area.
For example, in an image forming apparatus having recording heads of four colors K, C, M, and Y (FIG. 1, 104), image data that has been color-separated into four colors K, C, M, and Y is represented by K components. Image data for the head for ejecting K ink (FIG. 1, 105Bk), C component image data for the image area for the head ejecting C ink (FIG. 1, 105C), and M component image data is in the image area for the head that ejects M ink (FIG. 1, 105M), and Y component image data is in the image area for the head that ejects Y ink (FIG. 1, 105Y). At the time of printing, printing is performed by transferring print data from each image development area (FIG. 1 105) to each recording head (FIG. 1, 104).
(For example, Patent Document 1)

JP2003-145899, (page 3, Fig.1)

However, when it is desired to dramatically increase the printing speed, it is difficult to realize a printing speed that exceeds the performance of the recording head with the conventional configuration.
As a countermeasure against the above problem, there is a method of obtaining a printed matter by performing a recording operation in parallel on a plurality of recording devices. For example, when obtaining a printed matter including a serial number, management such as prevention of duplication of serial numbers shared by the recording devices is performed. The above problem also becomes apparent.

  In order to solve the above problems, an image forming apparatus according to the present invention implements an image forming apparatus and an image formation control program described below.

That is, an image is formed by ejecting ink droplets onto a recording medium from a conveying unit that conveys the recording medium and nozzle rows of each of the plurality of recording heads arranged perpendicular to the conveying direction of the recording medium. The image forming apparatus of the present invention includes:
The image forming apparatus includes divided image forming means for dividing and forming image data of the same color by the plurality of recording heads.

  Further, the divided image forming means of the image forming apparatus according to the present invention is characterized in that the image data of the same color is sequentially shared for each raster by n recording heads to form an image.

  The divided image forming means of the image forming apparatus according to the present invention is a means for forming an image by sequentially sharing image data of the same color for each raster by n recording heads. An image having the same resolution is formed by / n program control processes.

The image forming apparatus according to the present invention also includes a single image forming unit for forming an image with one recording head and an image forming unit for forming an image by sharing the image with n recording heads. An image forming unit, wherein the single image forming unit and the divided image forming unit are selectable.

  The image forming apparatus according to the present invention is characterized in that the single image forming unit and the divided image forming unit are used in combination.

  Further, the plurality of recording heads provided in the image forming apparatus according to the present invention have a nozzle row corresponding to the maximum recording width of the recording medium.

  The image forming apparatus according to the present invention is characterized in that when the divided image forming unit is selected, a recording speed approximately n times as high as that when the single image forming unit is selected is obtained.

  The image forming apparatus according to the present invention is characterized in that the recording medium is conveyed at a substantially constant speed during a recording operation.

  The image forming apparatus according to the present invention is characterized in that the plurality of recording heads are stationary during a recording operation.

Conveying means for conveying the recording medium, and a plurality of recording heads arranged from the upstream side to the downstream side in the conveying direction of the recording medium;
An image forming control program of the present invention in an image forming apparatus that forms an image by ejecting ink droplets from a nozzle row of each of the plurality of recording heads arranged perpendicular to the transport direction to a recording medium,
`` Divided image forming process '' in which image data of the same color is dividedly formed by the plurality of recording heads,
It is characterized by having.

  Further, the divided image forming step of the image forming control program according to the present invention is characterized in that the image data of the same color is sequentially assigned to each raster by n recording heads to form an image.

  The divided image forming step of the image forming control program according to the present invention is a step of forming an image by sequentially sharing image data of the same color for each raster by n recording heads. An image having the same resolution is formed by 1 / n program control processing.

  The image formation control program of the present invention forms an image by dividing the image forming process by one recording head and the n recording heads as an image forming process for forming image data of the same color. A divided image forming step, wherein the single image forming step and the divided image forming step can be selected.

  The image formation control program according to the present invention is characterized in that the single image formation step and the divided image formation step are used in combination.

  The image forming control program of the present invention is characterized in that when the divided image forming process is selected, a recording speed approximately n times as high as that when the single image forming process is selected is obtained.

  As described above, according to the image forming apparatus and the image forming control program of the present invention, the printing speed can be dramatically increased without changing the mechanism / hardware.

Further, as a derivative advantage of the present invention, it is possible to suppress an increase in the temperature of the recording head even during a high-speed recording operation, and to reduce the influence on the image quality even if there is an accidental discharge failure. Significant effects such as improved head durability can be obtained.
In addition, according to this configuration, simply changing the ink color supplied to the recording head (with a common mechanical / hardware configuration), a single color high speed machine (6 black heads), a color machine (3 black heads, cyan / A magenta / yellow head each), a high-quality machine (black / cyan / magenta / yellow / light cyan / light magenta head each), and ultimately a high-speed / ultra-high-quality machine (black / cyan / magenta) / Yellow / light cyan / light magenta, etc.)

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)

FIG. 2 is a block diagram for explaining the main part of a printing system in which a host computer is connected to the printing apparatus used in this embodiment.
As this printing apparatus, a monochrome printing apparatus using an inkjet method using four long line heads is used.
The printing apparatus (207) and the host computer (206) are connected by a printer cable (208), and various data processed by the host computer (206) are recorded by the printing apparatus (207), and the printing apparatus (207) The printer status such as error information 207) can be detected by the host computer (206).
The printing apparatus (207) incorporates four black ink jet line heads (201BK to 204BK) as recording means, supplies ink from a common ink tank (not shown), and sets the transport unit (102). By driving, the recording medium (101) which is continuous paper is fed below the recording head, and the recording medium detection of the recording medium detection sensor (103) is used as a trigger by each recording head (201 to 204). Recording is performed on the recording medium (101).
FIG. 3 is an electrical block diagram of the image forming apparatus used in this embodiment.
The control unit (301) includes a processing unit CPU (302), executes a control program stored in the memory ROM (303), and controls each peripheral device. The control unit (301) includes a memory RAM (304) used as a work area for various data processing and a reception buffer, an image memory (305) used as an image development unit, and the like. Further, the control unit will be described. By this control unit (301), various recording heads (201BK to 204BK) and various motors (306) for controlling a cleaning operation and a printing operation for keeping the recording head in an optimum state for printing. A servo motor drive circuit (310) for driving a conveyance motor (311) capable of conveying a recording medium passing under the recording head at high speed, and a rotary encoder for detecting rotation coupled to the motor shaft of the conveyance motor (311) (312) further includes a control circuit (307) for controlling the speed of the transport motor (311) and controlling the recording data transfer to the head drive circuit (313) by the encoder output fed back.
The image forming apparatus basically receives image data, a cleaning command, and the like transmitted from the host computer (206) via a printer cable such as a USB via the USB interface (308), and receives the received various command commands. Works according to.
The characteristic print control of the present invention will be described below with reference to FIG.

  Synchronously with the position signal of the recording medium (101) sequentially output from the encoder (312), the recording data for one raster is first transferred from the black image memory (205) to the black head 1 (201) for raster drawing. 1 (401) is obtained. Similarly, the data for the next one raster is transferred from the black image memory (205) to the black head 2 (202) in synchronization with the next position signal, and the raster drawing 2 (402) is further synchronized with the next position signal. Then, the data for one raster in the black image memory (205) is transferred to the black head 3 (203), and the raster drawing 3 (403) is further synchronized with the next position signal in the black image memory (205). By transferring the data to the black head 4 (204), the raster drawing 4 (404) is obtained. Thereafter, similarly, the black heads 1 to 4 (401 to 404) are assigned in units of one raster to obtain an output image.

  A series of printing (recording) operations will be described based on the detailed time chart of FIG.

  First, the physical dimensions from the detection position of the leading edge detection sensor (103) of the recording medium to the recording head (201BK) on the most upstream side in the transport direction are set to 2 inches, and the interval between the recording heads is set to 1 inch. The nozzle pitch (resolution) of (201BK to 204BK) is 600 [dot / inch], and the maximum recording (printing) width is 4 inches. Accordingly, each recording head (201BK to 204BK) uses 2400 [Nozzle] for recording.

  Recording speed (conveyance speed): 24 [inch / sec] (about 610 [mm / sec]).

  Further, since the printing (recording) resolution is 600 [dot / inch] in the recording medium conveyance direction, printing for 600 lines (raster) per inch is also performed in the conveyance direction.

The output resolution of the rotary encoder (312) coupled to the motor shaft of the transport motor (311) is, for example, 150 pulses per inch of the transport path, that is, one position pulse is output for every four print rasters. ): When set to 24 [inch / sec], the encoder (312) outputs 3600 pulses (average value) of position pulses per second (not shown).

  For example, the position pulse is used as a trigger (print start) signal for each raster printed by the most upstream recording head (201BK), and the remaining three recording heads (202BK to 204BK) are each 70 [μsec] from the position pulse. A print start signal having a delay of 139 [μsec] and 208 [μsec] is generated. These delay times are changed according to the recording speed.

  Returning to FIG. 5 again, the leading edge of the recording medium entering at a constant speed is detected by the leading edge detection sensor (103) and further conveyed by 2 inches, the leading raster (raster 0001) is recorded by the most upstream recording head (201BK). Is then printed, and the thinned print proceeds on the recording medium in the order of raster 0005⇒0009.

  When the sheet is further conveyed by 1 inch, printing of the second raster (raster 0002) from the top is started by the second recording head (202BK), and then the thinned print is added in the order of raster 0006⇒0010.

  When the conveyance further proceeds by 1 inch, printing of the third raster (raster 0003) from the top is started by the third recording head (203BK), and then the thinned print is added in the order of raster 0007⇒0011.

  Then, when the conveyance further proceeds by one inch, the printing of the fourth raster (raster 0004) from the head is started by the most downstream (fourth) recording head (204BK), and then in the order of raster 0008⇒0012. The thinned print is added, and the formation of a completed image starts from this point.

  After that, continuous printing at a high speed of a predetermined length continues, and when it reaches the vicinity of the final printing portion, the recording head 201BK first has a raster: Fin-11 (raster 11 rasters before the final raster) → raster: Fin-7 ⇒ Raster: Printing is completed in the order of Fin-3.

  When the recording operation is continued and further conveyed by 1 inch, the recording head 202BK prints in the order of raster: Fin-10 (raster 10 rasters before the final raster) ⇒ raster: Fin-6 ⇒ raster: Fin-2 Complete.

  When the sheet is further transported for 1 inch, printing is completed in this order by the recording head 203BK in the order of raster: Fin-9 (raster 9 rasters before the final raster) → raster: Fin-5 → raster: Fin-1. To do.

  When the sheet is further conveyed by 1 inch, the recording head 204BK on the most downstream side causes raster: Fin-8 (raster 8 rasters before the final raster) → raster: Fin-4 → raster: Fin (final raster). Printing is performed in order, and image formation of a predetermined length (raster 0001 to raster: Fin) is completed at this point.

  As described above, the monochrome image data developed in the continuous area is printed in a unit of one raster using, for example, four black recording heads, whereby the recording speed of one recording head: 6 A printing throughput four times that of [inch / sec], that is, a recording speed of 24 [inch / sec] can be obtained.

  Further, as a derivative effect to be shared, the recording characteristics inherent to the nozzles of the recording heads (201BK to 204BK) are not continuous, and are dispersed and recorded, for example, every four rasters, so that the image quality is dramatically improved.

This is nothing but an improvement in image quality reliability against accidental ejection failures. .
(Other examples)

  In the first embodiment, an example in which four black heads are used as recording heads has been described. Needless to say, the present invention can be applied to a configuration in which two or more recording heads in charge of recording of the same color exist. For example, if six black heads are used, an effect 1.5 times that of the first embodiment can be obtained.

  In the first embodiment, a monochrome printing machine has been described as an example. However, it may be applied to a full-color printing machine with a configuration of three black heads, one cyan head, one magenta head, and one yellow head. good. In this case, for example, there are several options such as high-speed printing by applying raster division control with three black heads in monochrome printing mode and high-quality printing without applying raster division control in full-color printing mode. An image forming apparatus (printing apparatus) can be considered.

It is a block diagram of the image forming apparatus by a prior art example. 1 is a configuration diagram of an image forming apparatus embodying the present invention. 1 is an electrical block diagram of an image forming apparatus embodying the present invention. It is a figure for demonstrating the printing control of the image forming apparatus which implemented this invention. FIG. 5 is a time chart for explaining details of FIG. 4.

Explanation of symbols

201BK recording head (black 1)
202BK recording head (black 2)
203BK recording head (Black 3)
204BK recording head (Black 4)
205BK Image image storage memory (Black)
206 Host computer 207 Image forming apparatus (printing apparatus)
208 Printer cable

301 Control unit 302 CPU
303 Program storage memory 304 Reception and work memory 305 Image image storage memory 306 Various motors 307 Control circuit (gate array, etc.)
308 USB controller 310 Servo motor drive circuit 311 Conveyance motor 312 Encoder 313 Recording head drive circuit

401 Raster image obtained with a black 1 recording head 402 Raster image obtained with a black 1 recording head 403 Raster image obtained with a black 1 recording head 404 Raster image obtained with a black 1 recording head

Claims (15)

An image for forming an image by ejecting ink droplets onto a recording medium from a conveying unit that conveys the recording medium and a nozzle row of each of the plurality of recording heads arranged perpendicular to the conveying direction of the recording medium In the forming device,
"Divided image forming means" for dividing and forming image data of the same color by the plurality of recording heads,
An image forming apparatus comprising:   The image forming apparatus according to claim 1, wherein the divided image forming unit forms an image by sequentially sharing image data of the same color for each raster by n recording heads.   The divided image forming means is a means for forming an image by sequentially sharing image data of the same color for each raster by n recording heads, and in the raster control, the program control process is 1 / n times the number of rasters. The image forming apparatus according to claim 1, wherein an image having the same resolution is formed.   As image forming means for forming image data of the same color, the image forming means includes a single image forming means for forming an image with one recording head, and a divided image forming means for forming an image by sharing with n recording heads, The image forming apparatus according to claim 1, wherein a single image forming unit and the divided image forming unit are selectable.   The image forming apparatus according to claim 1, wherein the single image forming unit and the divided image forming unit are used in combination. The image forming apparatus according to claim 1, wherein the plurality of recording heads include a nozzle row corresponding to a maximum recording width of the recording medium.   5. The image forming apparatus according to claim 4, wherein when the divided image forming unit is selected, a recording speed approximately n times as high as that obtained when the single image forming unit is selected is obtained. The image forming apparatus according to claim 1, wherein the recording medium is conveyed at a substantially constant speed during a recording operation. The image forming apparatus according to claim 1, wherein the plurality of recording heads are stationary during a recording operation. Conveying means for conveying the recording medium, and a plurality of recording heads arranged from the upstream side to the downstream side in the conveying direction of the recording medium;
In an image forming apparatus for forming an image by ejecting ink droplets from a nozzle row of each of the plurality of recording heads arranged at right angles to the transport direction onto a recording medium,
`` Divided image forming process '' in which image data of the same color is dividedly formed by the plurality of recording heads,
An image formation control program characterized by comprising:   11. The image forming control program according to claim 10, wherein the divided image forming step forms an image by sequentially sharing image data of the same color for each raster by n recording heads.   The divided image forming step is a step of forming an image by sequentially sharing image data of the same color for each raster by n recording heads. In the raster control, the divided image forming step is a program control process 1 / n times the number of rasters. The image formation control program according to claim 10, wherein an image with the same resolution is formed.   As an image forming process for forming image data of the same color, a single image forming process for forming an image with one recording head and a divided image forming process for forming an image by sharing with n recording heads, The image forming control program according to claim 10, wherein a single image forming step and the divided image forming step can be selected.   The image forming control program according to claim 10, wherein the single image forming step and the divided image forming step are used in combination. 14. The image forming control program according to claim 13, wherein when the divided image forming process is selected, a recording speed approximately n times as high as that obtained when the single image forming process is selected is obtained.