JP2007130924A - Inkjet recorder with both-sided printing function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent an offset of both-sided printing from occurring in an inkjet recorder. <P>SOLUTION: The inkjet recorder having a both-sided printing function is provided with a measuring means for measuring a print density of a recording medium. Print profiles different in the print density are printed in one-sided printing. Offset densities of the print profiles are measured, and an ink discharge density is adjusted according to the offset densities, so that the offset is not generated in the both-sided printing. Also provided is such a function that a user is made to check on the offset of the printing profiles and to input to what extent the user can tolerate the offset. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus having a double-sided printing function, and more particularly to ink discharge density adjustment for preventing show-through in double-sided printing.

  In consideration of the environment, there are increasing opportunities to reduce the amount of printing paper used by printing on both sides when printing, and to make effective use of resources. Also, double-sided printing is more effective than single-sided printing from the viewpoint of storage space for the recording medium, and it is considered that opportunities for double-sided printing will increase in the future.

  However, when double-sided printing is performed with an inkjet recording apparatus, there is a problem in that printing on the back surface of the recording medium moves through the recording medium surface depending on the type of the recording medium, and so-called show-through occurs, making it difficult to see the printed image. Sometimes.

  Patent Document 1, Patent Document 2, Patent Document 3 and the like are publicly disclosed as conventional techniques for the problem of show-through in double-sided printing by an ink jet recording apparatus.

  Patent Document 1 prevents show-through by selecting a processing liquid mode or an ink discharge amount low density mode based on a user input.

  Patent Document 2 prevents show-through by automatically selecting a print mode in accordance with the ink ejection duty on both sides.

Patent Document 3 is configured so that the standby time before the start of the back surface recording after the front surface recording of the recording medium at the time of double-sided recording can be varied according to the type of the recording medium. By adjusting the ink discharge density according to the paper, show-through is prevented.
JP-A-9-254376 JP 2003-34133 A Japanese Patent No. 2879872

  These proposals are methods to prevent double-sided printing show-through by an inkjet recording device by adjusting the ink discharge density according to an index that affects the show-through. It is not measured whether there is a reflection. For this reason, there is a possibility that a show-through that the user cannot actually tolerate has occurred.

  The present invention has been made to prevent show-through of double-sided printing of an inkjet recording apparatus, and an inkjet recording apparatus having a double-sided printing function is provided with a measuring means for measuring the printing density of a recording medium. Print profiles with different print densities are printed by single-sided printing, measure the show-through density of the print profile, adjust the ink discharge density according to the show-through density, and prevent the show-through from occurring during duplex printing. Also, a function is provided that allows the user to see the print profile show-through and allows the user to input what show-through is acceptable. Here, in the present invention, it is assumed that the print-through by the print-through density acceptable by the user is prevented.

  By actually measuring the show-through density of the print profile for single-sided printing, the ink can be used according to the actual usage environment, such as the type of recording medium, usage environment such as temperature and humidity, product variations, especially ink head nozzle variations, etc. Since the discharge density can be adjusted, it is possible to prevent show-through during double-sided printing. In addition, it is possible to approach the quality desired by the user by having the user input how much show-through can be allowed.

Example 1
A first embodiment of the present invention will be described using an ink jet printer (hereinafter abbreviated as IJP) shown in FIG. The present invention is not limited to this embodiment, and can be applied to an ink jet printer having another structure.

  FIG. 1 is a schematic sectional view of the IJP. 11 is a paper tray, 21 and 22 are paper discharge trays, 31 is an ink head, 41 is a CCD, 101 is a paper feed roller, 102 to 104 are transport rollers, and 105 and 106 are paper discharge rollers. The show-through print density of the recording medium is measured by the CCD 41.

  In a normal inkjet recording apparatus, there are two types of user input: single-sided printing or double-sided printing. However, in the present invention, in order to adjust the ink discharge density during double-sided printing, the print profile is printed on one side to adjust the show-through density. Processing to measure is added. Therefore, there are three types of user input. Hereinafter, the process for measuring the print-through density of the print profile and adjusting the ink discharge density during double-sided printing will be referred to as the print-through print density measurement mode.

  FIG. 2 shows an example of a print profile used for the measurement of the show-through density in the show-through print density measurement mode. By measuring the show-through density of such a print profile, the ink discharge density is adjusted. If further adjustment is desired, the print-through density is measured by using a print profile having a large number of print profile patterns as shown in FIG. 3 to adjust the ink discharge density. For paper having a low show-through density such as double-sided glossy paper, the ink discharge density is not adjusted, and image formation is performed with the same ink discharge density as single-sided printing.

  Next, FIG. 4 is a flowchart showing processing performed by IJP in response to user input. After the power is turned on, the system stands by until any one of the show-through print density measurement mode, duplex printing, or simplex printing is input. This process is repeated until the power is turned off.

  FIG. 5 is a flowchart showing the flow of the show-through print density measurement mode. The show-through print density measurement mode is completed by printing the print profile on one side, inverting the paper, measuring the show-through density of the print profile, and storing the show-through data for the ink discharge density in the nonvolatile storage device. . These series of processes are automatically performed by the ink jet recording apparatus.

  Next, FIG. 6 is a flowchart showing a detailed flow of processing including a paper path. The inversion of the sheet is performed by conveying the sheet in the order of S15, S16, S17, and S18 shown in FIG. In double-sided printing, the ink discharge density is set so that the show-through density is equal to the show-through density set as the reference value (hereinafter referred to as the standard show-through density) based on the data stored in the nonvolatile storage device. Make adjustments.

  Since the printing paper and usage environment do not change frequently, after executing the print density measurement mode, the ink discharge amount is adjusted according to the data stored in the nonvolatile storage device unless the print density measurement mode is executed again. Perform double-sided printing. When the printing paper or the usage environment changes, the user executes the print density measurement mode again.

(Example 2)
A second embodiment of the present invention will be described using an ink jet printer. Since the overall configuration of the apparatus is the same as that of the first embodiment, detailed description thereof will be omitted, and only the features will be described below. The present invention is not limited to this embodiment, and can be applied to an ink jet printer having another structure.

  In the first embodiment, the ink discharge density is adjusted so that the show-through density is equal to the show-through density based on the reference show-through density. The acceptable range of reflection is subjective and varies from person to person. Further, if the main focus is on preventing show-through and the ink discharge density is too low, the quality of the essential image may be degraded.

  In view of this, the numbered print profile as shown in FIG. 7 is viewed by the user, and it is possible to select which print density should be used for image formation based on the balance between the formed image and the show-through. Further, a user who desires more detailed settings is configured to be able to select a printing density with which printing is good by having a numbered printing profile as shown in FIG.

  As a method of setting the print density selected by the user looking at the print profile, after printing the print profile, an input screen as shown in FIG. 9 or 10 is displayed on the PC display, and the screen click or numerical value is displayed to the user. Have it set by input.

  The setting of the print density by the user is called a print density user setting mode, and FIG. 11 shows a flowchart of the print density user setting mode. Next, FIG. 12 is a flowchart showing processing performed by IJP in response to user input. In the first embodiment, there are three types of user input, but in the second embodiment, the print density user setting mode is increased to four types.

  Since the printing paper and usage environment are not changed frequently, the ink discharge amount is determined by the data stored in the non-volatile storage device after executing the print density user setting mode unless the print density user setting mode is executed again. Adjust and print on both sides. When the printing paper or the usage environment changes, the user again executes the print density measurement mode or the print density user setting mode for print density adjustment.

(Example 3)
A third embodiment of the present invention will be described using an ink jet printer. Since the overall configuration of the apparatus is the same as that of the first embodiment, detailed description thereof will be omitted, and only the features will be described below. The present invention is not limited to this embodiment, and can be applied to an ink jet printer having another structure.

  In the first embodiment and the second embodiment, the specific gravity of the show-through density on the front surface and the back surface is treated equally and the ink discharge density is adjusted. However, the front surface (the main printing surface) forms a high-quality image. There is a case where it is desired to perform double-sided printing under the condition that there is almost no show-through, low-quality image formation is performed on the back side (non-main print side), and there is no problem with show-through. In the description of the present invention, such adjustment of the ink discharge density of double-sided printing is referred to as single-sided discharge density adjustment.

  In the single-sided discharge density adjustment, an image is formed on the front surface without adjusting the ink discharge density, and the ink discharge density is adjusted only on the back surface. As a method for the user to set the print density value on the back side, an input screen as shown in FIG. 13 is displayed on the display of the PC, and the user inputs a numerical value. When the user wants to confirm the show-through, click the print to perform double-sided printing, and after confirming the show-through, if the print density value is determined, click Enter. As shown in FIG. 14, double-sided printing is performed in which the ink discharge density value of the back surface is image-formed on the print surface of the back surface so that the ink discharge density value printed on the back surface can be seen. FIG. 15 shows a flowchart of single-side discharge density adjustment.

Schematic sectional view of IJP. Example of printing profile. Example of printing profile with many patterns. The flowchart which shows the process with respect to user input. 6 is a flowchart showing processing in a show-through print density measurement mode. The flowchart which shows the flow of the detailed process with respect to each input. Example print profile for user settings. Example of print profile with a large number of patterns for user settings. Example 1 of print density setting input screen. Example 2 of print density setting input screen. 10 is a flowchart showing processing in a print density user setting mode. 6 is a flowchart for user input including a print density user setting mode. An example of an input screen for single-sided discharge density adjustment. An example of confirmation printing of double-sided printing in which ink discharge density values are recorded. The flowchart of single-sided discharge density adjustment.

Explanation of symbols

1 IJP body 11 Paper tray 21, 22 Paper discharge tray 31 Ink head 41 CCD
101 Feed roller 102 to 104 Transport roller 105, 106 Paper discharge roller

Claims (3)

  Ink jet recording apparatus that performs printing by ejecting ink according to a signal in an ink jet recording apparatus having a double-sided printing function capable of single-sided printing and double-sided printing on a recording medium, and transporting the recording medium during single-sided printing and double-sided printing Inkjet recording apparatus comprising: conveying means for performing measurement; measuring means for measuring print density of recording medium; means for printing one side of print profile, measuring show-through density thereof and adjusting ink discharge density during double-sided printing .   2. The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus includes means for allowing a user to set an allowable range of the show-through density by looking at the show-through density of the print profile.   The ink jet recording apparatus according to claim 1, wherein the ink jet recording apparatus has means for setting the show-through density on the front surface and the show-through density on the back surface to different show-through densities according to a user setting. .

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