WO2016075961A1

WO2016075961A1 - Inkjet printer

Info

Publication number: WO2016075961A1
Application number: PCT/JP2015/070341
Authority: WO
Inventors: 優介花島
Original assignee: 株式会社沖データ・インフォテック
Priority date: 2014-11-14
Filing date: 2015-07-16
Publication date: 2016-05-19

Abstract

With inkjet printers, there are cases in which, depending on the type of print medium, areas between formed dots cannot be filled in with ink and complete coating is not possible. When processing image data so as to fill in areas between dots using only discharge and no discharge, the problem of reduced image quality occurs. In the present invention, using RIP processing that is capable of adjusting ejection volume for deep and light colors, image data is generated as one bit long data for each pixel and each color and is output to the printer. Then, in order to adjust solid filling, the present invention makes it possible to vary deep color discharge volumes from discharge/no discharge data by setting light color ink to be ejected in regions of high density and expanding deep color data inside the printer. The present invention limits increases in image processing time in the host PC and makes it possible to obtain favorable solid filling.

Description

inkjet printer

The present invention relates to an inkjet printer.

Inkjet printers that record images by ejecting ink onto recording media such as recording paper and resin films are widely known. In an inkjet printer, an image is recorded by ejecting ink while moving a recording head having a plurality of nozzles arranged along the conveyance direction of the recording medium in a direction perpendicular to the conveyance direction of the recording medium. There is something to do.

This type of ink jet printer is equipped with black, cyan, magenta and yellow inks and recording heads for each ink when performing color recording. Further, in order to more suitably express intermediate colors, there is a six-color machine in which two colors of light cyan and magenta are added in which the amount of pigment contained in cyan and magenta inks is reduced. In addition, there are some which add light gray or light gray with less pigment contained in black ink. Some recording heads can change the dot size formed on the recording medium in a plurality of stages by changing the amount of ink to be landed. This is because image data of one pixel of one color is composed of data of 2 bits or more, and the amount of ink ejected from the recording head and landing on the recording medium is varied according to the data. Thus, there are advantages such as increasing the ink color and changing the dot size to widen the range of color gradation expression and improve the image quality of the recorded image.

On the other hand, some inkjet printers can print only specific image data. In such an ink jet printer, the host computer converts the image data into printable image data, and the ink jet printer acquires the image data from the host computer and prints it. In an ink jet printer, ink is ejected from a recording head of each color to a recording medium based on received image data, and an image is recorded. For example, when an inkjet printer records with four colors of ink, image data for four colors is generated by the host computer, and for six colors, image data for six colors is generated, and the image data is printed by the inkjet printer. . Inkjet printers do not operate correctly even if incorrect image data is input.

For example, Japanese Patent Laid-Open No. 2002-248837 discloses a technique for generating image data of four colors and six colors. If such a technique is used, it is possible to convert the original image into four or six colors.

On the other hand, for example, in an ink jet printer used for textile printing for printing on a fabric or the like, an ink of a color arbitrarily prepared by a user may be used instead of a preset ink color. At this time, it is impossible to design the image quality of the printer using the preset ink color. When the composition of the ink color to be used is different, there is a possibility that a desired image quality cannot be obtained unless printing control is performed exclusively for the ink color.

JP 2002-248837 A

In an inkjet printer that ejects small droplets of ink from a print head to form an image, the solid print portion may not be filled depending on the type of recording medium. It is known that the existing technology does not select image data from ejection and non-ejection, but uses ejection data as multi-bit data and performs processing according to the value. However, in this case, it is known to use a great deal of time for image processing.
In addition, when the user arbitrarily replaces the color ink, the solid may not be completely filled in the print mode in which the image data does not have a plurality of bits.

An inkjet printer according to the present invention includes a recording head arranged corresponding to each of a plurality of colors of ink, an input unit for inputting RIP-processed image data, a storage unit for storing the image data, and the storage unit Control means for controlling the ejection of the ink from the recording head based on the image data stored in the recording medium, and ejecting the ink from the recording head to a recording medium based on the image data for recording. In the ink jet printer that performs, the recording head can change the ink amount ejected from the nozzle in a stepwise manner based on the control data input to the recording head, and the control data determines the ink amount from the recording head. It is composed of at least three values for selecting whether to discharge less, whether to discharge a larger amount of ink, or not to discharge, The data length of the control data is longer than the data length of the image data, and the image data corresponds to the discharge color data corresponding to the plurality of colors of ink and a color different from the discharge color and corresponding to the discharge color. Spot color data to be controlled, and the control means takes a logical product of the discharge color data corresponding to the same pixel of the image data and the spot color data corresponding to the discharge color data, and outputs the logical product to the discharge color data. A product result is added, the result of the addition is used as the control data, and the control data is sent to the recording head.

In addition, the inkjet printer of the present invention adjusts the solid filling when image processing is output to the printer with 1 bit data for each color and 1 pixel by using RIP software capable of adjusting the dark and light colors. In addition, the data set so that light color ink is set in the dark area is expanded inside the printer, or the data of two colors selected arbitrarily is expanded inside the printer. It becomes possible to select the discharge amount of dark color from the discharge data, and it is possible to minimize the increase in image processing time on a PC (personal computer) and obtain a suitable solid filling. It has the control which becomes possible.

According to the present invention, it is possible to provide an ink jet printer that can use the generated image data of the number of ink colors as image data of a printer different from the number of ink colors.

FIG. 1 is a flowchart for explaining the operation. FIG. 2 is a diagram illustrating the configuration of the ink jet printer. FIG. 3 is a block diagram of the ink jet printer. FIG. 4 is a diagram for explaining the outline of handling image data. FIG. 5 is a diagram for explaining the data width of the print data. FIG. 6 is a diagram for explaining ejection data based on a combination of color data. FIG. 7 is an external view of the ink jet printer. FIG. 8 is a diagram for explaining the handling of arbitrarily designated two-color data.

Embodiments of the present invention will be described with reference to the drawings.
An example of an ink jet printer will be described with reference to FIG. FIG. 7 is an external view of the ink jet printer. The ink jet printer 1 supports the housing 2 with legs 20. The leg portion 20 is fixed to and supported by the lower surface of the housing 2. The recorded recording medium 13 is discharged along the front paper guide 22 from the gap between the front paper guide 22 and the window portion 21 in the direction indicated by the arrow.

Furthermore, the inside is explained. FIG. 2 is a diagram illustrating the configuration of the ink jet printer. The housing 2 constitutes the exterior of the inkjet printer 1. The recording head 5 is an ink jet head that ejects ink. The recording head 5 is mounted on the carriage 4 and reciprocates over the recording medium 13. Four recording heads 5 corresponding to inks of four colors of black, cyan, magenta, and yellow are mounted on the carriage 4. Four or more colors may be used. The recording medium 13 is intermittently conveyed while being attracted to the flat platen 6. An image is recorded by ejecting ink from the recording head 5 onto the recording medium 13 supported by the platen 6. A desired image is completed by repeating conveyance and recording while scanning.

The carriage 4 is guided by the linear rail 3 and reciprocally scans in a direction intersecting with the conveyance direction of the recording medium 13, that is, a direction orthogonal in this example. The carriage 4 is fixed to the belt 7. The belt 7 is wound around a pair of pulleys 9. A motor 8 is connected to one pulley 9, and the carriage 4 reciprocates along the rail 3 by driving thereof. The position of the carriage 4 can be acquired by detecting the linear scale 10 arranged along the moving direction of the carriage 4 with the encoder 11.

The platen 6 is provided with a plurality of suction holes and communicates with a duct 17 at the bottom of the platen 6. The duct 17 is connected to the fan 18 and sucks air from the suction hole by the fan 18. A maintenance unit 19 is disposed on the side of the platen 6 to clean the recording head 5.

The front paper guide 22 and the rear paper guide are arranged before and after the platen 6. The recording medium 13 is guided and conveyed in the order of the rear paper guide, the platen 6, and the front paper guide 22. Between the rear paper guide and the platen 6, a plurality of transport rollers 12 are arranged along the platen 6 at regular intervals. The conveyance roller 12 includes a pair of a driving roller and a pair of pinch rollers pressed against the driving roller. The conveyance roller 12 is sandwiched between two pairs of rollers, and the recording medium 13 is conveyed by the rotation of the driving roller.

FIG. 3 is a block diagram of the ink jet printer. The control circuit 30 is a control circuit that controls the entire inkjet printer 1. The I / F 31 is an interface with an external device. For example, it connects to the host PC 32 and inputs data such as image data. This image data is processed by RIP software, and is bitmap data converted into data for each pixel in accordance with the resolution of the printer. It is generated according to the ink color installed in the printer. For example, for a printer that uses four colors of ink, data of four colors is generated for one pixel. If there are six colors, data for each of the six colors is generated. This can be specified to obtain the desired data when generating the RIP.

The recording unit 33 includes the recording head 5 and is a unit that records an image on the recording medium 13 under the control of the control circuit 30. The carriage moving unit 34 includes a mechanism for reciprocally scanning the carriage 4 in the width direction of the recording medium 13, and can move the carriage 4 to a desired position along the rail 3 under the control of the control circuit 30. The media transport unit 35 includes a transport roller 12 and is a mechanism that transports the recording medium 13. The media transport unit 35 is controlled by the control circuit 30. The position detection unit 36 includes a linear scale 10 and an encoder 11 and detects the positions of the carriage 4 and the recording head 5. The detection result is output to the control circuit 30, and the control circuit 30 calculates and acquires the positions of the carriage 4 and the recording head 5. The position detection means 36 is controlled by the control circuit 30.

The ROM 37 is a non-volatile memory, and stores a program for controlling the ink jet printer 1, initial setting values, and the like. The control circuit 30 operates according to this program. The RAM 38 is a memory used for work memory of the control circuit 30 and temporary storage of data.

The control circuit 30 converts the captured image data into control data and sends it to each recording head 5. The control data is data of three or more values indicating whether ink is ejected and whether the ink amount is ejected. The recording head 5 inputs this control data to determine whether or not to eject ink and whether or not to increase the amount of ink. In the example described later, the data length of the control data is 2 bits. The control data takes a value corresponding to the multi-step amount of ink ejected from the recording head 5. If the data length is 2 bits, it can correspond to the ink amount up to 4 levels, and if the data length is 3 bits, it can correspond to the ink amount up to 8 levels. The control data has a data length twice that of the image data. For example, if the data length of one pixel of a certain color of image data is 1 bit, the control data has a data length of 2 bits.

FIG. 1 is a flowchart for explaining the operation. An ink jet printer 1 that is a printer that ejects four colors of ink is equipped with a recording unit 33 that can eject four colors of ink of black, yellow, cyan, and magenta. An operation when image data for a printer capable of ejecting six colors of ink is input to the four-color printer will be described. The six colors are black, yellow, cyan, and magenta. The pigment density is lower than that of dark cyan, and the lighter light cyan and darker magenta are used. Thus, the ink is a six-color ink obtained by adding a light magenta ink which is a light color. Here, the dark color and the light color corresponding to the dark color are controlled as different colors.

The recording head 5 of the recording means 33 mounted on the inkjet printer 1 can give 2-bit data to one pixel printed by one nozzle. The recording head 5 can change the ink ejection amount in accordance with the value of this data. This control is performed by the control circuit 30.

First, control of the inkjet printer 1, which is a device that ejects four colors of ink, is started. Next, image data of six colors, for example, a certain amount of data such as one scan, is transferred from the host PC 32 to the inkjet printer 1 (step S1). The inkjet printer 1 temporarily stores the transferred image data in the RAM 38 (step S2). Triggered by storing a certain amount of image data, the image data is transferred to the recording head 5 (step S3). Next, it is determined whether or not light ink data, that is, data of colors other than the four colors that can be recorded by the device, exists in the image data to be transferred (step S4). When it exists, it progresses to step S5, and when it does not exist, it progresses to step S6.

In step S5, 1 bit is added to the upper bits of the data of each dark color pixel to make it 2 bits long. Then, the amount of ink ejected is controlled based on the light ink data in accordance with preprogrammed conditions. Based on the data of the light ink, the data of each pixel of the image data is set as control data for the recording head 5 having an output of 2 bits with respect to 1 bit (step S5). Here, the dark color means cyan for light cyan and magenta for light magenta. Black and yellow are also dark. Light cyan and light magenta are light colors. If it does not exist, the upper bit of the data of each dark pixel, that is, the second bit is added, and the data of the value to be ejected is written there without increasing the amount of ink, and the recording is 2 bits long. Control data for the head 5 is set (step S6).

Next, it is determined whether or not printing is finished (step S7). If it is finished, the control is finished. If it is not finished, the process returns to step S1 to continue printing.
In this flowchart, when there is a light color corresponding to the dark color, the discharge amount of the dark color is corrected based on the light color data. However, as another example, the discharge amount can be corrected only for a predetermined dark and light color pair and the other amounts can be selectively controlled so as not to correct the discharge amount. For example, the case where the light color is a color such as yellow that has little influence on the dark color.

FIG. 4 is a diagram for explaining the outline of handling image data. As many recording heads 5 as the number of dark colors, that is, four recording heads are installed. From the host PC 32, the RIP-processed data of six colors of dark and light colors are transferred to the inkjet printer 1 via the I / F 31 in the order of lines to be printed. The transferred image data is 1-bit data for each pixel of each color. Next, the inkjet printer 1 temporarily stores image data in the RAM 38. After a certain amount of image data is stored in the RAM 38, the control data converted from the image data is transferred to the recording head 5. At this time, the inkjet printer 1 extends the dark color data from 1-bit data per pixel to 2-bit data. Specifically, the agricultural color data is used as the lower 1-bit data, and 1 bit is added to the higher-order data to generate 0-value data for non-ejection in the added second bit. Next, the logical product of the light color data and the dark color data of the image data is taken. The result is added to the extended 2-bit data and stored. Next, control data expanded to a 2-bit length is sent to each head. Accordingly, it is possible to control to increase the ejection amount when both dark color and light color image data are present.

FIG. 5 is a diagram for explaining the data width of the print data. The image data transferred from the host PC 32 is 1 bit long for one pixel of each color. The data stored in the RAM 38 is 1 bit long for one pixel. The image data transferred to the recording head 5 has a dark color of 2 bits per pixel, and the light color data is added to the dark color data. Therefore, only the light color data is not transferred to the recording head 5.

FIG. 6 is a diagram for explaining ejection data based on a combination of color data. Control is performed to increase the amount of ink to be ejected only when the dark color and light color ejection data, that is, both the second bit data and the first bit data are data indicating that ink is ejected. In the drawing, C of the ejection data stored in the RAM means cyan color, and Lc means light cyan color data. When 0, 0, 0, and 1, respectively, the output data to the print head is 00. Further, when it is 1, 0, it becomes 01 and forms a 1-drop dot, and when it is 1, 1, it becomes 10 and forms a 2-drop dot. In this example, the case of cyan shades has been described. In addition, the same data structure can be used for magenta shades. It has three values that allow selection of three patterns of ejection control: 1 drop with a small amount of ink, 2 drops with a large amount of ink, and no ejection. In order to have at least these three values, 2-bit data is sent to the print head. Here, the case where the amount of ink is large has been described as 2 drops, but an amount corresponding to 3 drops or 4 drops may be used.

When the dark color is non-ejection data (“0” in the figure), the recording head 5 is non-ejection. When the dark color is ejection data and the light color data is 0, the print head ejects 1 drop of ink. When both data are ejection data, the ejection of the print head ejects 2 drops of ink.

FIG. 8 is a diagram for explaining an outline of handling image data. In this figure, four recording heads 5 are installed as many as the number of colors to be ejected. From the host PC 32, the RIP-processed data of the four ejection colors and the four special colors are transferred to the inkjet printer 1 via the I / F 31 in the order of the lines to be printed. The transferred image data is 1-bit data for each pixel of each color. The four discharge colors are red R, green G, blue B, and yellow Y, and the four special colors are orange Or, white W, fluorescent pink Np, and fluorescent yellow Ny. In addition, a recording head that discharges ink of each color of R, G, B, and Y is provided. R, G, B, and Y inks are inks arbitrarily used by the user. Although there is no recording head for ejecting ink of the same color as Or, W, Np, and Ny, an optimal image can be recorded using the ink and recording head that are provided.

Next, the inkjet printer 1 temporarily stores image data in the RAM 38. After a certain amount of image data is stored in the RAM 38, the control data converted from the image data is transferred to the recording head 5. At this time, the ink jet printer 1 responds by extending the data corresponding to the recording head from 1-bit data per pixel to 2-bit data. Specifically, the data corresponding to the print head to be ejected is the lower 1 bit data, and 1 bit is added to the upper bit, and the value of 0 is set as non-ejection in the added second bit. Is generated. Next, the logical product of the non-ejection color data combined with the image data and the ejection color data is obtained. The result is added to the expanded 2-bit data and stored. Next, control data expanded to a 2-bit length is sent to each head. Accordingly, it is possible to control to increase the ejection amount when there is both ejection color and non-ejection color image data. For example, 2-bit data based on R color image data and Or color image data is generated on a recording head that discharges R color ink, and the ink amount is changed based on the generated data. become. Similarly, dots of G, B, and Y are recorded based on the image data of G and W, B and Np, and Y and Ny, respectively. As another example, a selection unit that selects a spot color corresponding to the discharge color is provided. For example, any one color of Or, W, Np, and Ny is selected and associated with the R color. As a selection method, an optimal value is set in advance as an initial setting value, and the setting value can be changed according to preference. The set value is stored in the RAM 38. The control circuit 30 acquires this set value and performs an operation based on the image data of the spot color corresponding to the discharge color corresponding to the setting. Although the description has been made using the RAM 38 as the setting value storage means, the setting value can also be stored in the ROM 37.

The present invention can be used for an ink jet printer. In particular, the present invention can be used for a large ink jet printer that records on a wide recording medium.

1 Inkjet printer 2 Housing 3 Rail 4 Carriage 5 Recording head 6 Platen 7 Belt 8 Motor 9 Pulley 10 Linear scale 11 Encoder 12 Transport roller 13 Recording medium

Claims

A recording head arranged corresponding to each of the plurality of colors of ink;
Input means for inputting RIP processed image data;
Storage means for storing the image data;
Control means for controlling the ejection of the ink from the recording head based on the image data stored in the storage means;
In an inkjet printer that performs recording by discharging the ink from the recording head to a recording medium based on the image data,
The recording head can change the ink amount ejected from the nozzles in a stepwise manner based on control data input to the recording head, and the control data ejects the ink amount from the recording head in a small amount, It is composed of at least three values for selecting whether to eject a large amount of ink or not, and the data length of the control data is longer than the data length of the image data,
The image data includes ejection color data corresponding to the plurality of colors of ink, and spot color data that is different from the ejection color and is controlled according to the ejection color.
The control means takes a logical product of the ejection color data corresponding to the same pixel of the image data and the spot color data corresponding to the ejection color data, adds the result of the logical product to the ejection color data, and An ink jet printer that performs control for setting a result of addition as the control data and sending the control data to the recording head.
2. The ink jet printer according to claim 1, wherein the ejection color data corresponds to a dark color among the colors of the ink, and the spot color data corresponds to a light color corresponding to the dark color.
The image data has been subjected to the RIP process corresponding to the six ink colors, and the recording head is arranged corresponding to four of the six ink colors, The two colors among the four colors are the dark colors, and two colors other than the four colors among the six colors are the light colors corresponding to the dark colors. inkjet printer.
The discharge means includes at least two colors having the spot color data corresponding to the discharge color data, and the control unit corresponds to only the spot color data based on the spot color data corresponding to the predetermined discharge color data. The inkjet printer according to any one of claims 1 to 3, wherein the control data is generated by calculating color data.
Setting value storage means for previously storing the spot color data corresponding to the ejection color data as a setting value is provided, and the control means corresponds to the ejection color data based on the setting value stored in the setting value storage means. The inkjet printer according to any one of claims 1 to 4, wherein the control data is generated based on the spot color data.