JPH0994944A - Ink recording type image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the blur or bleeding of ink by providing a means determining the time allowing a receiving material on which ink is recorded to stand. SOLUTION: A printing signal is outputted to a printing head 8 in predetermined timing from a control part 9. The control part 9 is equipped with a CPU 10, an I/O interface 12, a main memory 13 housing various data, an image memory control part 14, an image memory 15, a printing control part 16, an A/D converter 18 and a timer group 20 setting various standing times. Image data is taken in from an external device 11 such a personal computer or CAD through the I/O interface 12 and, when the image data is subjected to development processing under the control of the CPU 10 by the image memory control part 14, a printing ratio is also measured on the basis of image data. The control part 9 having a standing time determining means determines a standing time on the basis of the printing ratio.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. 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 having improved print quality.

[0002]

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 ejected from a recording means (recording head) onto a recording material (paper) is known. The ink jet type image forming apparatus can easily make the recording head compact, can record high-definition images at high speed, and can easily record color images using multicolor inks. Have advantages.

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, there is a possibility that the ink may not be completely dried yet. , There is a type that makes it impossible to remove the paper.

The operation of the conventional ink jet image forming apparatus will be described with reference to the flow chart shown in FIG.

As shown in FIG. 15, first, a sheet is set in the image forming apparatus (step S101), an image forming operation is performed (step S102), and the ink ejected onto the sheet is left for a predetermined time to dry. (Step S10
3) When the predetermined time has passed, the prohibition on the removal of the sheet is released, and the sheet can be removed (step S104).

[0006]

However, the time required to actually dry the ink ejected on the paper depends on the amount of ink ejected per unit area of the recording material (printing rate) for each image forming operation. different. Therefore, when the amount of ejected ink is large (when the printing rate is high), when the paper is removed from the image forming apparatus even after a lapse of a predetermined drying time, an image that is not completely dried due to rubbing or the like is disturbed, On the contrary, when the amount of ejected ink is small (when the printing rate is low), there is a possibility that an originally unnecessary drying time is spent.

Further, the drying time of the paper also varies depending on the indoor condition in which the image forming operation is performed (for example, indoor temperature, indoor humidity, etc.).

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 is different), or bleeding due to color mixture may occur at a boundary with another color.

Therefore, an object of the present invention is to provide an ink recording type image forming apparatus in which the rubbing and bleeding of ink is prevented.

[0010]

In order to solve the above-mentioned problems, the invention according to claim 1 is an image forming apparatus for forming an image on a recording material with ink, in which the recording material on which ink is recorded is left unattended. It is characterized in that it is provided with a leaving time determining means for determining the time to be kept.

According to the first aspect of the present invention, the leaving time determining means determines the time for which the recording material on which the ink has been recorded is left after the recording on the recording material with ink. When the determined leaving time elapses, for example, the recorded ink dries, so that rubbing or bleeding does not occur.

The invention according to claim 2 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.

According to the second aspect of the invention, the leaving time determining means determines the leaving time based on the printing rate. When the printing rate is high, the amount of ink adhered is naturally large, so that the leaving time is long, and when the printing rate is low, the leaving time may be short.

The invention according to claim 3 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.

According to the third aspect of the present invention, the leaving time determining means determines the leaving time based on at least one of temperature and humidity. When the temperature is high, the drying time is good and the standing time is short, and when the temperature is low, the drying time is long, so the standing time is long. When the humidity is low, the drying time is good and the standing time is short. When the humidity is high, the drying time is long, so the standing time is long.

According to a fourth aspect of the present invention, the area in which the leaving time determining means determines the leaving time is means for determining the leaving time in units of one band which is a unit printed by one scan of the carriage. Alternatively, it is characterized in that it is provided with a means for determining the leaving time in units of a region obtained by arbitrarily dividing one band, or a means for determining the leaving time in units of all the bands.

According to the invention described in claim 4, the leaving time determining means determines the leaving time in band units. When the standing time is determined in units of the area obtained by arbitrarily dividing one band, the drying time of a minute area is read, so that the optimum drying time can be calculated. Further, if all the bands are areas for determining the standing time, the processing (calculation) time of the drying time can be shortened.

The invention according to claim 5 is characterized by further comprising image forming speed changing means for changing the image forming speed on the basis of the leaving time determined by the leaving time determining means.

According to the fifth aspect of the invention, since the image forming speed can be changed by the image forming speed changing means, for example, bleeding occurs due to the ink before the change at the printing rate or the color change point. It is possible to prevent the ink from bleeding at the change point by ejecting the ink for a certain period of time so that there is no problem.

Further, the invention according to claim 6 is provided with a temporarily fixed state releasing means for releasing the temporarily fixed state of the recording material after the time determined by the leaving time determining means or during the time elapsed. Is characterized by.

According to the sixth aspect of the present invention, the temporarily fixed state releasing means sets the temporarily fixed state of the recording material at an arbitrary time after the time determined by the leaving time determining means or during the time elapse. To cancel. In this way, the ink is surely dried, and no unnecessary drying time is spent.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. The ink recording type image forming apparatus of this embodiment is an inkjet plotter.

(1) First Embodiment Example FIG. 1 is a perspective view of an essential part of the present embodiment example, FIG. 2 is a block diagram of a control system of the present embodiment example, and FIGS. It is a flow chart which shows operation of a form example.

First, the mechanical schematic structure of the embodiment will be described with reference to FIG.

As shown in FIG. 1, on the front side surface of the ink jet plotter 1 placed on the stand 7, there is provided a paper discharge section 2 for discharging the paper 6 having the ink image 5 formed thereon. A temperature detection unit 3 and a humidity detection unit 4 that detect the ambient temperature and humidity are attached to the lower surface of the paper discharge unit 2.

Next, the structure of the control system will be described with reference to FIG.

As shown in FIG. 2, the control unit 9 outputs a print signal 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, and a main memory 1 in which various data (see FIGS. 8 to 11) described later are stored.
3, 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 types of leaving time described below.
Reference numeral 17 is an external disk memory for storing image data, and reference numeral 19 is an input / output device for designating the number of prints, the size of paper, and the like.

Then, an external device 1 such as a personal computer or CAD
The image data is loaded from 1 through the I / O interface 12 and developed by the image memory control unit 14 under the control of the CPU 10.

Here, the expansion processing means converting the image data sent from the external device 11 into printable data when the image data is stored in the image memory 15. This expansion process is performed in band units (print units formed by one carriage scan) as shown in FIG. 7, and in this expansion process, the amount of ink ejected per unit area of the paper based on the image data. Information (hereinafter referred to as print ratio) is also measured.

The print data (image data) stored in the image memory 15 is controlled by the print control unit 1 under the control of the CPU 10.
An image 5 is formed on the paper 6 by being read by a print signal output from the printer 6 at a predetermined timing and transferred to the print head 8 to eject ink.

On the other hand, the respective detection values detected by the temperature detecting section 3 and the humidity detecting section 4 are fetched into the CPU 10 via the A / D converter 18 as temperature information and humidity information.

Next, based on FIG. 3, FIG. 4 and FIG.
The operation of the example embodiment will be described.

As shown in FIG. 3, the paper is set at a predetermined position of the inkjet plotter (step S1), the image forming operation is started (step S2), and the image data of each band (see FIG. 7) is predetermined. The drying time of the slice block group cut along the width is calculated (step S3).
Figure 4 shows the procedure for calculating the drying time for this slice block group.
It will be described based on the flowchart shown in FIG.

As shown in FIG. 4, the drying time of the slice block group is calculated by first calculating the drying time corresponding to the printing rate (step S21). For that purpose, attention is paid to each slice block group shown in FIG. 7, and the area divided therein (for example, the unit blocks 11, 12 in FIG.
.., 1j), and the drying time corresponding to the printing rate is calculated.

In the present embodiment, in order to determine the printing rate, as shown in FIG. 7, one band printed by one carriage scan is divided into i in the vertical direction into slice block groups, and each slice is divided into slice blocks. A unit block is obtained by dividing the block group into j in the horizontal direction. The number of print dots per unit block is counted under the control of the CPU 10 to determine the print rate. Then, based on the determined printing rate, information on a plurality of drying times prepared in advance in the main memory 13 using the printing rate as a parameter (see FIG. 9) to information on the drying time of the paper corresponding to the printing rate. Is selected (step S22). For example, when the printing rate is 30%, the drying time is 0.4 seconds.

In this way, the maximum value of the plurality of drying times corresponding to the obtained printing rate is adopted as the drying time of the slice block group (step S23). Then, based on FIG. 10, processing for correcting the 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 the direction from the first slice block group to the i-th slice block group (the printing direction from left to right), so that the left side (for example, the first slice) that was previously printed is printed. Block group) is printed
Since the time after printing has elapsed, the correction value for the drying time is "zero seconds", and the correction value for the drying time is "0.8 seconds" for printing in the middle portion (for example, the slice block group 650).
Seconds ".

The drying time information (FIG. 9) thus obtained and the correction value (FIG. 10) are obtained in step S of FIG.
4, the timer group 20 is set as a timer value.
Start one of.

Next, the slice block group is shifted (second slice block group shown in FIG. 7) (step S
7) Similarly to the above, the drying time of the slice block group is calculated (step S3), the calculated time is compared with the value of the timer group 20 shown at that time (step S5), and the timer value is updated with a larger value. Yes (step S6). In this way, steps S3 to S8 are repeated until the final slice block group (i-th slice block group) is reached.

When the calculation of the drying time of the final slice block group is completed (step S8; YE
S) Further, the timer value is updated in consideration of the information on the room temperature and humidity (steps S9 and S10), and the drying time of the band is calculated. This operation is repeated until the final band, and the timer value is updated each time, and the final drying time is set. Here, the method of correcting the effect of the room temperature and humidity on the drying time in step S9 is based on a plurality of correction values using the room temperature and humidity information prepared in the main memory 13 as parameters (see FIG. 11). , Select a correction value that matches the detected room temperature and humidity information, and add the correction to the drying time.

When printing is completed (step S11; YES), after the drying time set as described above has elapsed (step S12), the prohibition of paper removal is released (step S13). If necessary, information that informs the user that the drying time has elapsed is output (step S14).

In the present embodiment, as shown in FIG. 7, the print rate is calculated for each adjacent unit block such as the unit block 11 and the unit block 12 in order to calculate the drying time. However, as shown in FIG. 8B, the print position may extend over the unit block 11 and the unit block 12. In such a case, as shown in FIGS. 8 (A) and 8 (C), if the unit block for which the print ratio is to be obtained is shifted to form the unit block 11.5, the print ratio that is more practical can be obtained. It becomes possible to calculate.

The printing rate may be obtained by shifting the slice block group.

(2) Second Embodiment Example The difference between the present embodiment example and the first embodiment example is that the first embodiment example is different from each slice block group shown in FIG. 7 in the paper drying time calculation. In contrast to this, in the present embodiment example,
The point is that each band shown in FIG. 7 is focused.

The flowchart of this embodiment is shown in FIGS. 5 and 6.

First, as shown in FIG. 5, the paper is set at a predetermined position of the ink jet plotter (step S3).
1) The image forming operation is started (step S32), and then the band drying time is calculated (step S33).
The calculation of the drying time of this band will be described based on the flowchart shown in FIG.

As shown in FIG. 6, the drying time of the band is calculated by first calculating the drying time corresponding to the printing rate (step S51) and for all one band (step S52). During this drying time, correction is performed by taking into account information on the temperature and humidity inside the room (step S5).
3).

Then, in step S34 of FIG.
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).

Then, the band is shifted (step S
36, shift to the second band in FIG. 7), calculate the drying time of the band in the same manner as described above (step S33), set the value in another timer of the timer group 20 and start it (steps S34, S35). ).

This operation is repeated until the final band (step S37), and the timer is sequentially started for each band. After the printing is completed, the printing is completed because all timers are counted up (step S38).

When the printing is completed (step S38; YES), after the drying time set as described above has elapsed (step S39), the prohibition of paper removal is released (step S40). If necessary, information that informs the user that the drying time has elapsed is output (step S41).

(3) Third Embodiment Example FIG. 12 is a block diagram of a control system of the present embodiment example. It should be noted that FIG. 12 is based on the block diagram shown in FIG.
The humidity detector 4 and the A / D converter 18 are deleted.

As shown in FIG. 13, the paper is set at a predetermined position of the ink jet plotter (step S61),
The image forming operation is started to print the unit block (step S62). At this time, similar to the first embodiment, the image data is fetched from the external device 11 via the I / O interface 12, and is developed in the image memory control unit 16 under the control of the CPU 10. This expansion process is performed in band units 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 information on a plurality of drying times (see FIG. 9) prepared in advance in the main memory 13 using the printing rate as a parameter, and information on the drying time of the paper suitable for the printing rate obtained by the above means. Pick out. Thus, the drying time after printing the fixed area is calculated (step S63).

After printing 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). . When the drying time has elapsed (step S66; YES), the process returns to step S62 again, and steps S62 to S6.
Repeat 6 to the final block (step S
67).

If the carriage is stopped during the formation of one band, the carriage may be stopped at that position or in the non-printing area. Especially, in the ink jet recording apparatus, when the printing is stopped for a long time. The recovery operation (such as the operation of wiping the ejection port surface of the recording head with a blade) may be performed. Further, when the printing rate is low, bleeding does not occur, and therefore printing is not stopped in order to provide a drying time.

By controlling the printing operation in this way, it is possible to prevent the harmful effects due to bleeding.

(4) Fourth Embodiment Example A block diagram of a control system of the present embodiment example is the same as that shown in FIG.

As shown in FIG. 14, the paper is set at a predetermined position of the ink jet plotter (step S71),
The image forming operation is started to print the unit block (step S72). At this time, as in the third embodiment, the drying time after printing the fixed area is calculated (step S7).
3) Further, similarly to the first embodiment, the drying time is corrected in consideration of room temperature and humidity (step S74).

Then, after printing the fixed area, the printing is stopped (step S75), 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 S76). . If the drying time has not elapsed (step S77; NO), the process returns to step S72 again and steps S72 to S7.
Repeat 6 to the final block (step S
78).

In the third embodiment, the drying time is calculated from the information on the amount of ink ejected per unit block of paper, but in the third embodiment, the temperature detecting unit 3 and the humidity shown in FIG. 1 are used. Each of the detection values obtained by the detection unit 4 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.

This method of correcting the drying time is performed by the above-mentioned means from a plurality of correction values (see FIG. 10) having room temperature and humidity information as parameters set in advance in the main memory 13. Select the correction value that suits to and calculate the drying time.

In each of the above-described embodiments, as a method of measuring the printing rate, a method of measuring (counting) from the information of the image data at the time of the expansion processing as described above is adopted. A method of counting how much ink has been ejected per unit movement amount during the printing operation or a method of detecting the image density formed during the actual printing operation with a sensor may be used.

Further, in each of the embodiments, 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 is finally counted up after the printing operation is completed. However, the timer counting method does not perform comparison and updating as in the present embodiment, but the timer works in each block and all timers count up. You may wait. Alternatively, a method may be used in which the drying time of the paper is adjusted by adjusting the printing speed and the transportation speed of the paper in consideration of the required drying time.

Here, adjusting the printing speed means
This is to change the ink ejection interval from the print head 8 and accordingly change the carriage movement speed. In addition, adjusting the conveyance speed of the paper means changing the rotation speed of the conveyance roller and thereby changing the feed speed of each band of the paper.

[0064]

As described above, according to the invention described in each claim, after the ink is recorded on the recording material, the leaving time is determined to determine the time for which the ink-recorded recording material is left. Since the temporary fixing state releasing means for releasing the temporarily fixed state of the recording material after the time determined by the leaving time determining means has elapsed, the ink is removed when the paper is removed after the image forming operation is completed. It is possible to perform the image forming operation without causing deterioration of image quality due to rubbing and bleeding, which may occur when the image is not completely dried, and without spending unnecessary time.

[Brief description of drawings]

FIG. 1 is an external perspective view of a first embodiment example of the present invention.

FIG. 2 is a block diagram of a control system of the first embodiment example.

FIG. 3 is a flowchart of the first embodiment example.

FIG. 4 is a flowchart of a subroutine (during drying time calculation) of the flowchart shown in FIG.

FIG. 5 is a flowchart of the second embodiment example.

FIG. 6 is a flowchart of a subroutine (during drying time calculation) of the flowchart shown in FIG.

FIG. 7 is a conceptual diagram showing a slice state of image data in each embodiment example.

FIG. 8 is a conceptual diagram of another example of a sliced state of image data in each embodiment, (A) is a conceptual diagram viewed macroscopically, and (B) and (C) are how to take unit blocks. FIG. 6 is a diagram showing a situation in which a printing rate is different depending on.

FIG. 9 is a diagram showing a drying time corresponding to a printing rate used in each embodiment example.

FIG. 10 is a diagram showing a drying time corresponding to the position of a slice block group in one band used in each embodiment example.

FIG. 11 is a diagram showing a drying time corresponding to temperature and humidity used in each embodiment example.

FIG. 12 is a block diagram of a control system of the third embodiment example.

FIG. 13 is a flowchart of the third embodiment.

FIG. 14 is a flowchart of the fourth embodiment example.

FIG. 15 is an operation flowchart of a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Inkjet plotter 3 Temperature detection unit 4 Humidity detection unit 6 Paper 8 Print head 9 Control unit (leaving time determining unit, temporary fixed state releasing unit) 10 CPU 11 External device 13 Main memory 14 Image memory control unit 15 Image memory 20 Timer group

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichizo Kobayashi 6-3-3 Shimorenjaku, Mitaka City, Tokyo Copier Co., Ltd.

Claims (6)

[Claims] 1. An image forming apparatus for forming an image on a recording material with ink, comprising an leaving time determining means for determining a time for leaving the recording material on which the ink has been left. Image forming apparatus. 2. The ink recording type image forming apparatus according to claim 1, wherein the leaving time determining means includes means for determining the leaving time based on the printing rate of the recording material. 3. The ink recording type image forming apparatus according to claim 1, wherein the leaving time determining means includes means for determining the leaving time based on at least one of temperature and humidity. apparatus. 4. The area for determining the leaving time by the leaving time determining means is means for determining the leaving time in units of one band which is a unit printed by one scan of the carriage,
Alternatively, the apparatus further comprises means for determining a leaving time in units of a region obtained by arbitrarily dividing one band, or means for determining a leaving time in units of all bands.
4. The ink recording type image forming apparatus according to claim 3. 5. The ink recording method according to claim 1, further comprising image forming speed changing means for changing the image forming speed based on the leaving time determined by the leaving time determining means. Image forming apparatus. 6. The temporary fixing state releasing means for releasing the temporarily fixed state of the recording material after or during the time determined by the leaving time determining means, is provided. The ink recording type image forming apparatus according to claim 5.