JP3605196B2 - Ink recording type image forming apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink recording type image forming apparatus, and more particularly to an ink recording type image forming apparatus with improved print quality.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as one type of an ink recording type image forming apparatus, an ink jet type in which ink is discharged from a recording unit (recording head) onto a recording material (paper) is known. The ink jet type image forming apparatus is easy to make the recording head compact, capable of high-speed recording of high-definition images, and easy to record color images using multi-color inks. Has advantages.
[0003]
In such an ink jet type image forming apparatus, when the paper is removed from the image forming apparatus after the image forming operation is completed, the ink may not be completely dried. Some types make removal impossible.
[0004]
Here, the operation of the conventional ink jet type image forming apparatus will be described based on a flowchart shown in FIG.
[0005]
As shown in FIG. 15, first, paper is set in the image forming apparatus (step S101), an image forming operation is performed (step S102), and the ink ejected onto the paper is left for a predetermined time to dry (step S103). If the predetermined time has elapsed, the prohibition of paper removal is released, and the paper can be removed (step S104).
[0006]
[Problems to be solved by the invention]
However, the time required to dry the ink actually ejected on the paper differs depending on the amount of ink ejected per unit area (printing rate) of the recording material for each image forming operation. Therefore, when the amount of ejected ink is large (when the printing rate is high), even when a predetermined drying time has elapsed, when the paper is removed from the image forming apparatus, an image that has not been completely dried due to rubbing or the like is disturbed. Conversely, when the amount of ejected ink is small (when the printing rate is low), unnecessary drying time may be spent.
[0007]
Further, the drying time of the sheet varies depending on the indoor state (for example, indoor temperature, indoor humidity, etc.) in which the image forming operation is performed.
[0008]
Further, when the printing rate is high, bleeding may occur at a change point of the printing rate (a boundary portion where the printing rate differs), or bleeding may occur due to color mixture at a boundary with another color.
[0009]
Therefore, an object of the present invention is to provide an ink recording type image forming apparatus which prevents rubbing and bleeding of ink.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is an image forming apparatus that forms an image on a recording material with ink, wherein, during a printing operation, for each of a plurality of unit areas that form an image on the recording material, The apparatus further includes a leaving time determining unit that determines a leaving time for keeping the recording material, and the leaving time determining unit sequentially updates the leaving time determined for the unit area on which an image is to be formed, with time, The updated leaving time is compared with the leaving time determined for the next unit area, and the leaving time for the recording material is determined based on the larger leaving time. It is characterized in that it is determined that the ink of the recording material has dried.
According to a second aspect of the present invention, in the image forming apparatus for forming an image on a recording material with ink, the recording material is left in each of a plurality of unit areas for forming an image on the recording material during a printing operation. A leaving time determining means for determining the leaving time to be kept, the leaving time determining means updates the leaving time determined for each unit area with the passage of time, and when the leaving time for all unit areas has elapsed, It is characterized in that it is determined that the ink of the recording material has dried.
[0011]
According to the first aspect of the present invention, after the recording on the recording material by the ink, the leaving time determination means determines the time for leaving the recording material on which the ink recording has been performed. If the determined leaving time elapses, for example, the recorded ink dries, so that no rubbing or bleeding occurs.
[0012]
Further, the invention according to claim 3 is characterized in that the leaving time determining means includes means for determining the leaving time based on the printing rate of the recording material.
[0013]
According to the third aspect of the present invention, the idle time determining means determines the idle time based on the printing rate. When the printing rate is high, the amount of ink adhered is large, so that the leaving time requires a long time, and when the printing rate is low, the leaving time may be short.
[0014]
Further, the invention according to claim 4 is characterized in that the leaving time determining means includes means for determining the leaving time based on at least one of temperature and humidity.
[0015]
According to the invention described in claim 4 , the leaving time determining means determines the leaving time based on at least one of the temperature and the humidity. When the temperature is high, the drying time is short because the drying is good, and when the temperature is low, the drying time is long because the drying time is long. When the humidity is low, the drying time is short because the drying is good, and when the humidity is high, the drying time is long because the drying time is long.
[0016]
Further, in the invention described in claim 5 , the unit area is one band which is a unit printed by one scan of the carriage or an area obtained by arbitrarily dividing one band .
[0017]
According to the fifth aspect of the present invention, the leaving time determining means determines the leaving time in band units or in an area obtained by arbitrarily dividing one band. Thereby, since the drying time of the minute area is read, the optimum drying time can be calculated .
[0018]
According to a sixth aspect of the present invention, there is provided an image forming speed changing means for changing an image forming speed based on the idle time determined by the idle time determining means.
[0019]
According to the sixth aspect of the present invention, the image forming speed can be changed by the image forming speed changing means, so that, for example, at the point where the printing rate or the color is changed, the ink before the change does not cause bleeding. The ink can be prevented from bleeding at the changed point by ejecting the ink after setting the idle time.
[0020]
Further, in the invention according to claim 7, the leaving time determination means has a timer for setting / updating the leaving time, and when the leaving time set / updated in the timer has passed, the recording material is determined. It is characterized in that it is determined that the ink has dried.
[0021]
According to the invention described in claim 8, the idle time determination means has a plurality of timers for setting the idle time of each of the plurality of unit areas, and the idle time set for all of the plurality of timers. When the elapsed time, it is determined that the ink of the recording material has dried.
ADVANTAGE OF THE INVENTION According to this invention, an ink dries reliably and does not waste useless drying time.
[0022]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiment. The ink-recording type image forming apparatus of the embodiment is an ink-jet plotter.
[0023]
(1) First Embodiment FIG. 1 is a perspective view of a main part of the present embodiment, FIG. 2 is a block diagram of a control system of the present embodiment, and FIGS. 3 and 4 are diagrams of the present embodiment. It is a flowchart which shows an operation.
[0024]
First, a schematic mechanical configuration of the present embodiment will be described with reference to FIG.
[0025]
As shown in FIG. 1, a paper discharge unit 2 that discharges a paper 6 on which an ink image 5 is formed is provided on a front side surface of the inkjet plotter 1 mounted on a stand 7. A temperature detecting unit 3 and a humidity detecting unit 4 for detecting the surrounding temperature and humidity are attached to the lower surface of the sheet discharging unit 2.
[0026]
Next, the configuration of the control system will be described based on FIG.
[0027]
As shown in FIG. 2, a print signal is output from the control unit 9 to the print head 8 at a predetermined timing. The control unit 9 includes a CPU 10, an I / O interface 12 connected to the CPU 10, a main memory 13 storing various data (see FIGS. 8 to 11) described below, an image memory control unit 14, , An image memory 15, a print control unit 16, an A / D converter 18, and a timer group 20 for setting various leaving times described below. Reference numeral 17 denotes an external disk memory for storing image data, and reference numeral 19 denotes an input / output device for designating the number of prints, the size of paper, and the like.
[0028]
Then, image data is fetched from an external device 11 such as a personal computer or CAD via the I / O interface 12, and is developed by the image memory control unit 14 under the control of the CPU 10.
[0029]
Here, the expansion processing refers to converting the image data sent from the external device 11 into printable data when storing the image data in the image memory 15. This developing process is performed in band units (printing units formed by one carriage scan) as shown in FIG. 7, and in this developing process, the amount of ink ejected per unit area of paper based on image data Information (hereinafter referred to as a printing rate) is also measured.
[0030]
The print data (image data) stored in the image memory 15 is read out by a print signal output from the print control unit 16 at a predetermined timing under the control of the CPU 10 and transferred to the print head 8 to eject ink. To form the image 5 on the paper 6.
[0031]
On the other hand, the respective detection values detected by the temperature detection unit 3 and the humidity detection unit 4 are taken into the CPU 10 via the A / D converter 18 as temperature information and humidity information.
[0032]
Next, the operation of the first embodiment will be described with reference to FIGS.
[0033]
As shown in FIG. 3, a sheet is set at a predetermined position of the inkjet plotter (step S1), an image forming operation is started (step S2), and the image data of the band unit (see FIG. 7) is cut at a predetermined width. The drying time of the slice block group thus calculated is calculated (step S3). The procedure for calculating the drying time of this slice block group will be described based on the flowchart shown in FIG.
[0034]
As shown in FIG. 4, in the calculation of the drying time of the slice block group, first, the drying time corresponding to the printing rate is calculated (step S21). For this purpose, paying attention to each slice block group shown in FIG. 7, a drying time corresponding to a printing rate in an area divided therein (for example, unit blocks 11, 12,..., 1j in FIG. 7) is calculated. .
[0035]
In the present embodiment, in order to determine the printing rate, as shown in FIG. 7, one band printed and formed by one carriage scan is divided into i in the vertical direction to form a slice block group. A horizontal block divided by j is defined as a unit block. The number of printing dots per unit block is counted under the control of the CPU 10, and the printing rate is determined. Then, based on the determined printing rate, information on the drying time of the paper corresponding to the printing rate is obtained from a plurality of pieces of drying time information (see FIG. 9) using the printing rate prepared in advance in the main memory 13 as a parameter. Is selected (step S22). For example, when the printing rate is 30%, the drying time is 0.4 seconds.
[0036]
In this manner, the maximum value among the plurality of drying times corresponding to the obtained printing ratio is adopted as the drying time of the slice block group (step S23). Then, based on FIG. 10, a process of correcting a difference in the drying time caused by the position of the slice block group is performed (step S24), and the value is set as the drying time of the slice block group. That is, as shown in FIG. 7, the printing direction is from the first slice block group to the i-th slice block group (printing direction from left to right). In the printing of the block group), since the time after printing has elapsed, the correction value of the drying time is “zero second”, and the printing value of the intermediate portion (for example, the slice block group 650) is the correction value of the drying time. Set to “0.8 seconds”.
[0037]
The drying time information (FIG. 9) and its correction value (FIG. 10) obtained as described above are set as timer values as shown in step S4 of FIG. 3, and one of the timer groups 20 is started.
[0038]
Next, the slice block group is shifted (second slice block group shown in FIG. 7) (step S7), and the drying time of the slice block group is calculated in the same manner as described above (step S3), and the calculated time and the time are shown. The value of the timer group 20 is compared (step S5), and the timer value is updated with a larger value (step S6). Steps S3 to S8 are repeated until the last slice block group (i-th slice block group) is reached.
[0039]
Then, when the calculation of the drying time of the last slice block group is completed (step S8; YES), the timer value is further updated in consideration of the information on the indoor temperature and humidity (steps S9 and S10). Calculate the drying time of the band. This operation is repeated until the last band, and the timer value is updated each time to set the final drying time. Here, the method of correcting the influence of the room temperature and humidity on the drying time in step S9 is based on a plurality of correction values using information of room temperature and humidity prepared in advance in the main memory 13 as parameters (see FIG. 11). Then, a correction value corresponding to the detected information of the room temperature and the humidity is selected, and the drying time is corrected.
[0040]
When the printing is completed (step S11; YES), after the drying time set as described above elapses (step S12), the prohibition of paper removal is released (step S13). Information that informs the user that the drying time has elapsed is output (step S14).
[0041]
In this embodiment, as shown in FIG. 7, the printing rate is obtained for each adjacent unit block such as the unit block 11 and the unit block 12 in order to obtain the drying time. However, as shown in FIG. 8B, the printing position may straddle the unit block 11 and the unit block 12. In such a case, as shown in FIGS. 8A and 8C, if the unit block for which the printing rate is to be determined is shifted to the unit block 11.5, the printing rate that is more practical can be obtained. It can be calculated.
[0042]
Further, the printing rate may be obtained by shifting the slice block group.
[0043]
(2) Second Embodiment The difference between this embodiment and the first embodiment is that the first embodiment focuses on each slice block group shown in FIG. 7 in calculating the paper drying time. On the other hand, the present embodiment is focused on each band shown in FIG.
[0044]
5 and 6 show flowcharts of the present embodiment.
[0045]
First, as shown in FIG. 5, a sheet is set at a predetermined position of the ink jet plotter (step S31), an image forming operation is started (step S32), and then a band drying time is calculated (step S33). The calculation of the drying time of the band will be described with reference to the flowchart shown in FIG.
[0046]
As shown in FIG. 6, in the calculation of the drying time of the band, first, the drying time corresponding to the printing rate is calculated (step S51), and the calculation is performed for all the bands (step S52). At this drying time, correction is performed in consideration of the information on the temperature and humidity in the room (step S53).
[0047]
Then, in step S34 of FIG. 5, the timer value determined as described above is set as the drying time of the band, and one timer of the timer group 20 is started (step S35).
[0048]
Next, the band is shifted (step S36, shift to the second band in FIG. 7), the dry time of the band is calculated in the same manner as described above (step S33), and the value is set in another timer of the timer group 20. It is started (step S34, step S35).
[0049]
This operation is repeated until the last band (step S37), and the timer is sequentially started in band units. After the printing is completed, the printing is completed by counting up all the timers (step S38).
[0050]
Then, when printing is completed (step S38; YES), after the drying time set as described above elapses (step S39), the prohibition of paper removal is released (step S40), and if necessary, Information that informs the user that the drying time has elapsed is output (step S41).
[0051]
(3) Third Embodiment FIG. 12 is a block diagram of a control system according to this embodiment. FIG. 12 is obtained by removing the temperature detector 3, the humidity detector 4, and the A / D converter 18 from the block diagram shown in FIG.
[0052]
As shown in FIG. 13, a sheet is set at a predetermined position of the ink jet plotter (step S61), and an image forming operation is started to print a unit block (step S62). At this time, similarly to the first embodiment, image data is fetched from the external device 11 via the I / O interface 12, and is processed by the image memory control unit 16 under the control of the CPU 10. This development processing is performed for each band as shown in FIG. 7, the printing rate per unit block is measured, and the drying time is calculated. This calculation method is based on a plurality of pieces of drying time information prepared using a printing rate as a parameter in the main memory 13 (see FIG. 9). Choose out. Thus, the drying time after the printing of the fixed area is calculated (step S63).
[0053]
After the printing of the fixed area, the printing is stopped (step S64), and the stop time until the printing of the next area is different depending on the printing rate of the fixed area, and the time is counted up (step S65). If the drying time has elapsed (step S66; YES), the process returns to step S62 again, and repeats steps S62 to S66, and repeats until the last block (step S67).
[0054]
If the carriage is stopped during the formation of one band, the carriage may be stopped at that position or in a non-printing area. (Such as an operation of wiping the ejection port surface of the recording head with a blade). In addition, when the printing rate is low, there is no possibility of bleeding, so that printing is not stopped to provide a drying time.
[0055]
By controlling the printing operation in this way, it is possible to prevent adverse effects due to bleeding.
[0056]
(4) Fourth Embodiment The block diagram of the control system of this embodiment is the same as that of FIG.
[0057]
As shown in FIG. 14, a sheet is set at a predetermined position of the inkjet plotter (step S71), and an image forming operation is started to print a unit block (step S72). At this time, as in the third embodiment, the drying time after printing the fixed area is calculated (step S73), and the drying time is corrected in consideration of the room temperature and the humidity as in the first embodiment (step S73). Step S74).
[0058]
After the printing of the fixed area, the printing is stopped (step S75), and the stop time until the printing of the next area is changed depending on the printing rate of the fixed area, and the time is counted up (step S76). If the drying time has not elapsed (step S77; NO), the process returns to step S72 again, and repeats steps S72 to S76, and repeats until the last block (step S78).
[0059]
In the third embodiment, the drying time is calculated from the information on the amount of ink ejected per unit block of paper. In the third embodiment, the temperature detecting unit 3 and the humidity detecting unit 4 shown in FIG. Each of the detected values obtained by the above is taken into the CPU 10 via the A / D converter 18, and the drying time calculated from the printing rate is corrected based on the temperature and humidity information.
[0060]
This method of correcting the drying time matches the room temperature and temperature information obtained by the above means from a plurality of correction values (see FIG. 10) using the room temperature and humidity information prepared in advance in the main memory 13 as parameters. Select a correction value and calculate the drying time.
[0061]
In each of the above-described embodiments, a method of measuring (counting) from information of image data at the time of development processing as described above is used as a method of measuring a printing rate. Alternatively, a method of counting how many inks are ejected per unit movement amount of, or a method of detecting an image density formed during an actual printing operation by a sensor may be used.
[0062]
Further, in each embodiment, as an algorithm for adjusting the drying time of the paper, the timer group 20 whose timer value is updated according to the printing rate during printing waits for the final counting up after the printing operation. However, the timer counting method does not compare and update as in the present embodiment, but the timer works in each block and waits for all timers to count up. You may. Alternatively, a method of adjusting the paper drying time by adjusting the printing speed and the paper transport speed in consideration of the necessary drying time may be used.
[0063]
Here, adjusting the printing speed means changing the ejection interval of the ink from the print head 8 and changing the moving speed of the carriage accordingly. Adjusting the transport speed of the paper means changing the rotation speed of the transport roller, thereby changing the feed speed of each band of the paper.
[0064]
【The invention's effect】
As described above, according to the invention described in each claim, after recording on the recording material by the ink, the recording device further includes a leaving time determination unit that determines a time for leaving the recording material on which the ink is recorded, After the elapse of the time determined by the idle time determination means, the prohibition of the removal of the recording material can be released . As a result, when the paper is removed after the end of the image forming operation, deterioration of the image quality due to rubbing and the like, which may occur when the ink has not been dried yet, does not occur, and wasteful time is unnecessary more than necessary. The image forming operation can be performed without any problem.
[Brief description of the drawings]
FIG. 1 is an external perspective view of a first embodiment of the present invention.
FIG. 2 is a block diagram of a control system according to the first embodiment.
FIG. 3 is a flowchart of the first embodiment.
FIG. 4 is a flowchart of a subroutine (at the time of calculating a drying time) of the flowchart shown in FIG. 3;
FIG. 5 is a flowchart of the second embodiment.
6 is a flowchart of a subroutine of the flowchart shown in FIG. 5 (when calculating a drying time).
FIG. 7 is a conceptual diagram illustrating a slice state of image data in each embodiment.
8A and 8B are conceptual diagrams of another example of a slice state of image data in each embodiment, in which FIG. 8A is a conceptual diagram viewed from a macroscopic view, and FIGS. FIG. 6 is a diagram showing a situation where the printing rate differs depending on the type.
FIG. 9 is a diagram showing a drying time corresponding to a printing rate used in each embodiment.
FIG. 10 is a diagram showing a drying time corresponding to a position of a slice block group in one band used in each embodiment.
FIG. 11 is a diagram showing a drying time corresponding to temperature and humidity used in each embodiment.
FIG. 12 is a block diagram of a control system according to the third embodiment.
FIG. 13 is a flowchart of the third embodiment.
FIG. 14 is a flowchart of the fourth embodiment.
FIG. 15 is an operation flowchart of a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ink-jet plotter 3 Temperature detection part 4 Humidity detection part 6 Paper 8 Print head 9 Control part (leaving time determination means, temporary fixed state release means)
10 CPU
Reference Signs List 11 external device 13 main memory 14 image memory control unit 15 image memory 20 timer group

Claims (8)

In an image forming apparatus for forming an image on a recording material with ink,
During a printing operation, for each of the plurality of unit areas for forming an image on the recording material, a leaving time determining unit that determines a leaving time for keeping the recording material is provided,
The leaving time determining means sequentially updates the leaving time determined for the unit area on which the image is to be formed earlier with time, compares the updated leaving time with the leaving time determined for the next unit area, Determining an idle time for the recording material based on the longer idle time, and determining that the ink of the recording material has dried when the idle time has elapsed; apparatus. In an image forming apparatus for forming an image on a recording material with ink,
During a printing operation, for each of the plurality of unit areas for forming an image on the recording material, a leaving time determining unit that determines a leaving time for keeping the recording material is provided,
The leaving time determining means updates the leaving time determined for each unit area as time elapses , and determines that the ink of the recording material has dried when the leaving time has elapsed for all unit areas. Ink recording type image forming apparatus. 3. The ink-recording type image forming apparatus according to claim 1, wherein said leaving time determining means includes means for determining a leaving time based on a printing rate of a recording material. 4. The ink-recording type image forming apparatus according to claim 1, wherein said leaving time determining means includes means for correcting the leaving time based on at least one of temperature and humidity. 5. The ink-recording image forming apparatus according to claim 1, wherein the unit area is one band which is a unit printed by one scan of the carriage or an area obtained by arbitrarily dividing one band. apparatus. 6. The ink-recording type image forming apparatus according to claim 1, further comprising an image forming speed changing unit that changes an image forming speed based on the idle time determined by the idle time determining unit. . The idle time determination means includes a timer for setting and updating the idle time, and when the idle time set and updated in the timer has elapsed, determines that the ink of the recording material has dried. The ink-recording type image forming apparatus according to claim 1. The leaving time determination means has a plurality of timers for setting the leaving time of each of the plurality of unit areas, and when the leaving time set for all of the plurality of timers has elapsed, the ink of the recording material is 3. The ink-recording type image forming apparatus according to claim 2, wherein it is determined that the ink has dried.

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