JPH08164601A - Ink jet recorder - Google Patents

Abstract

PURPOSE: To enable a material to be recorded to be discharged and stacked at an optimum timing by preventing sharp lowering of throughput. CONSTITUTION: When recording of one line is judged to be ended, recording duty of a proper line is recognized by counting with a recording cycle counter, and an LF motor is driven to send material to be recorded 12 by a specified distance Ln in a sub-scan direction. At that time, a driving start point of the LF motor is in reduced speed of the LF motor, and controlled so that a recording start point in a next line of the CR motor is conformed almost to a stop point of the LF motor. After repeating this operation, a line is recorded from an upper end of the material to be recorded 12. Thereafter, i.e., at a point of time before a tip 12a of the material to be recorded 12 comes in contact with a component in a stacker 25, or at a point of time before coming in contact with the stacked material to be recorded 12 after recording, a mean recording duty is calculated, and an optimum stop time is provided by referring to a table based on an experimental data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus having means for controlling deformation of a recording material after recording.

[0002]

2. Description of the Related Art Generally, in an ink jet recording apparatus, a recording material discharged after recording is placed on a stacker. At this time, immediately after recording, due to the water content of the ink on the recording surface of the recording material, the recording surface side of the recording material expands and curls to the side opposite to the recording surface, except for the special (for example, coated paper) recording material. Deformation will occur.

Due to the deformation of the curl or the like, as shown in FIG. 7, the leading end of the recording material is caught on the stacker side during discharging, and a to e of FIG.
As shown in FIG. 5, there is a problem such as a defective discharge or a jammed state. Further, as shown by the broken line portion in FIG. 8, the recording material after stacking may be buckled, and in this case, a failure such as ejection of the page and the following pages and a stack defect may occur. This has been a major problem in terms of paper ejection and stackability of recording materials. Note that the description of FIGS. 7 and 8 substitutes the description of FIGS. 1 and 2 described later.

In order to follow the recent trend toward lower processing costs and larger capacities of memories and higher performance of CPUs, the number of nozzles of recording heads and the speed of response have been increased. In some cases, it has emerged as a more prominent obstacle.

On the other hand, in the conventional ink jet recording apparatus, the following measures have been taken.

(1) A heating element is provided on the recording portion or on the upstream side or the downstream side thereof to accelerate the drying of the ink on the recording material.

(2) Read the recording duty of each line,
For example, a waiting time is provided when the paper is fed, or the feeding speed is slowed.

(3) Each part of the discharged recording material is mechanically pressed.

However, the conventional measures have the following problems.

In the above countermeasure (1), there are problems such as the cost required to install the heating element for promoting the drying of the ink, the power consumption when the heating element is used, and the responsiveness.

Further, the above countermeasure (2) has a problem that the throughput is lowered because it is stopped every line in the page.

Further, the above countermeasure (3) causes an increase in the mechanical size of the recording apparatus and causes a problem such as an increase in cost. In particular, in a recording apparatus capable of printing even a large size (A4 or larger) size, the above problem becomes remarkable.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus capable of preventing a significant decrease in throughput and reliably discharging and stacking a recording material at an optimum timing.

[0014]

In order to achieve the above object, an invention according to claim 1 is an ink jet recording apparatus, which is a recording means for ejecting ink droplets to record on a recording material. Conveying means for conveying the recording material to the recording area by the recording means, recording time recognizing means for recognizing the time required for recording within a predetermined range within the recording area on the recording material, and within the predetermined range Calculating means for calculating the recording duty, and, in a specific line in the recording area, the recording means when the required recording time recognized by the recording time recognizing means and the value calculated by the calculating means are predetermined values. On the other hand, a recording stop control means for controlling the recording operation by the recording means for a predetermined time is included.

The invention described in claim 2 is the same as claim 1.
The inkjet recording apparatus described above may further include a detection unit that detects a temperature, and the counting unit may calculate the recording duty by utilizing a temperature change of the recording unit.

According to a third aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the recording stop control means further includes a detection means for detecting temperature or humidity.
The stop time of the recording operation by the recording unit may be changed according to the value detected by the detecting unit.

According to a fourth aspect of the invention, in the ink jet recording apparatus according to the first aspect, the recording stop control means changes the stop time of the recording operation by the recording means according to the type or size of the recording material. It may be.

According to a fifth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the recording stop control means controls the recording operation by the recording means according to the composition of the ink ejected from the recording means onto the recording material. The stop time may be changed.

According to a sixth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the recording means is 81
It may be capable of ejecting ink to a recording material having a width of a digit or more.

According to a seventh aspect of the invention, in the ink jet recording apparatus according to the first aspect, the recording means is 70
10kHz including recording head with more than one nozzle
Ink may be ejected at the above ejection frequencies.

According to an eighth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, there is further provided a driving means for reciprocating the recording head of the recording means along a direction orthogonal to a conveying direction of the recording material. In addition, the recording means may perform the recording operation on both the forward and backward paths during the reciprocating movement by the driving means.

According to a ninth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the recording stop control means may be capable of setting conditions by an input from an external host device.

According to a tenth aspect of the invention, in the ink jet recording apparatus according to the first aspect, the recording stop control means may be capable of setting conditions by an internal input means.

According to an eleventh aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the predetermined range within the recording area on the recording material is 10 from the upper end of the recording material.
It may be in the lower part by about 0 mm.

According to a twelfth aspect of the present invention, in the ink jet recording apparatus according to the first aspect, the predetermined range within the recording area on the recording material is 10 from the lower end of the recording material.
It may be on the upper side by about 0 mm.

[0026]

According to the present invention, the time required for recording within the predetermined range of the recording material is recognized, the recording duty within the predetermined range is calculated, and the specified line of the page (for example, 10 from the upper end of the recording material) is calculated. In the 1st line of the line), control is provided so that the natural drying of the ink proceeds and the curl of the recording material returns to the recording surface side from the side opposite to the recording surface, and the optimum timing and stop time are provided. As a result, it is possible to prevent a significant decrease in throughput due to the conventional stop for every line, curl of the recording material is controlled at an optimum point in the apparatus configuration, and it is possible to reliably discharge and stack the recording material.

[0027]

Embodiments of the present invention will be described below in detail with reference to the drawings.

[Embodiment 1] FIG. 1 and FIG. 2 show an embodiment of an ink jet recording apparatus of the present invention, FIG. 1 is a plan view showing the whole apparatus, and FIG. It is the sectional view which looked at the device of the state where it was done from the side.

In FIGS. 1 and 2, reference numeral 1 is a recording head which constitutes a part of the recording means, 2 is a carriage on which the recording head 1 is mounted and which scans in the main scanning direction for recording. Is a CR motor that drives the carriage 2, 4 is a drive belt that transmits the driving force of the CR motor 3 to the carriage 2, 5 is a carriage shaft that guides the scanning of the carriage 2, and 6 is a cover to be described later. A conveying roller for conveying the recording material, 7 is an LF motor for driving the conveying roller 6, 8 is a pinch roller for pressing a recording material, which will be described later, against the conveying roller 6, and 9 is a sheet feeding motor (not shown). Is a paper feeding roller that is driven by the paper feeding stacker described below to feed the recording material to the conveying roller 6, 11 is a paper feeding stacker that stacks the recording material described below, and 12
Is a recording material, and 12a is 10 lines (about 85 mm)
Shows the position of the tip of the recording material 12 at the time of recording, and 13 is a control circuit for controlling the operation of the recording apparatus.
Is a recording position at which recording is performed on the recording material 12 by the recording head 1, 15 is a sensor for detecting whether or not the recording material exists between the paper feed stacker 11 and the recording position 14, and 24 is a sensor. A paper discharge roller is driven by the LF motor 7 in association with the transport roller, and a paper discharge stacker 25 stacks the discharged recording materials 12. The paper feed roller 9 and the paper feed stacker 11 form part of an automatic paper feed unit.

FIG. 3 shows the configuration of the control circuit 13 shown in FIG.

In FIG. 3, a CPU 16 in the form of a microprocessor is connected to a host device such as a host computer 18 and a scanner 19 via an interface 17, and a program memory 20 in the form of a ROM and a RAM.
The recording operation is controlled based on the recording data from the host device, which is stored in the buffer memory 21 of the type.

The CPU 16 controls the CR motor 3, the LF motor 7, and the paper feed motor 10 via the motor driver 22 and, based on the recording information stored in the RAM 21,
The recording head 1 is controlled via the head driver 23.

FIG. 4 is a flow chart showing the recording processing procedure by the CPU 16.

As shown in FIG. 4, after the control initialization at power-on (step S801), the reception interrupt is permitted (step S802). When print data is input from the host device connected to the printer of this embodiment in step S803, the received data is expanded into print data and stored in the print buffer provided in the RAM 21 in step S804. To do. The procedure of steps S803 to S805 is repeated until it is determined in step S805 that the recording start command has been received from the host device or the recording data for the predetermined amount (capacity of the reception buffer or one scan) has been received. Step S
In 805, if the recording condition is satisfied, recording is started.

Next, a control example of the recording operation for preventing the curl of the upper end of the recording material will be described with reference to the flowchart shown in FIG.

In this embodiment, the average recording duty from the upper end of the recording material to the 10th line is calculated, and
The recording time required for that is counted and recognized. These pieces of information are applied to a table preset based on the experimental data, and the recording operation is stopped for the predetermined time taken from this table.

The control method of the recording operation will be described in more detail below with reference to FIG.

In step S401, the carriage 2
To drive the CR motor 3 in the main scanning direction, and in step S402, the control circuit 13 sets data in the recording head 1 in step S402.
In step S403, the recording head 1 is driven.
The recording cycle counter provided in the RAM 21 is advanced every time the recording head 1 is driven, and it is determined by this recording cycle counter whether or not recording of one line is completed. From this determination result, in one scan of the print head,
If it does not exceed the default number of recorded dots, step S
Returning to step 401, the operations of steps S401 to S403 are repeated.

On the other hand, if it is determined in step S404 that the recording of one line is completed, the recording duty of the corresponding line is recognized in step S405 by the count of the recording cycle counter, and the LF motor 7 is detected in step S406. Drive the recording material 12
Is sent by a predetermined amount Ln in the sub-scanning direction. At this time, the driving start point of the LF motor 7 is at the time of deceleration of the CR motor 3, and the CR motor 3 of the next row is set at the stop point of the LF motor 7.
The throughput can be improved by controlling so that the recording start points (constant speed range) of are almost matched.

After repeating this operation, the recording material 12
10 lines from the upper end of the recording material 12, that is, before the leading end 12a of the recording material 12 contacts the constituent members of the paper discharge stacker 25 as shown in FIG. At the time before the contact with the, the average recording duty is calculated in step S408, and the optimum stop time can be set in step S409 by referring to the table created based on the experimental data as shown in Table 1. . Table 1 is a table showing the optimum stop time of the recording operation from the relationship between the required recording time experimentally detected in advance and the calculated recording duty.

[0041]

[Table 1]

According to the present embodiment, by controlling the stop time of the recording operation on the basis of the average recording duty and the required recording time in the predetermined range of the upper end of the recording material, which is apt to cause the trouble due to the curl, the curling is caused. By preventing obstacles and discharging and stacking the recording material at the optimum timing, and minimizing the stop time, it is possible to greatly reduce the decrease in throughput as compared with the past.

[Embodiment 2] In the above-mentioned Embodiment 1, an example of curl control of the upper end of the recording material is shown, but by substantially the same control, buckling of the lower end of the recording material during stacking is prevented. It is also possible.

In the present embodiment, it is possible to recognize the size of the recording material and control it by the feed amount from the upper end. However, as described below, the recording material provided on the upstream side of the recording area can be controlled. Management by the presence / absence detection sensor is less affected by variations in the size of the recording material and the feed amount, and is more reliable.

Hereinafter, description will be made with reference to the flowchart shown in FIG.

After the lower end of the recording material 12 passes the position of the sensor 15 shown in FIGS. 2 and 3 and "no recording material" is recognized in step S502, the recording material feed Ln is accumulated in the recording operation. L is a preset sensor 1
The recording operation of step S505 (same as S501) is repeated until the recordable distance L2 is exceeded after the lower end of the recording material 12 passes the position 5 (the recording operation shown here is S401 shown in FIG. 5). ~ S406).

After recording the recordable range, the average recording duty for 10 lines up to that is calculated in step S507, and the recording time required for that is taken into consideration.
A table (not shown) created for this control is referred to in the same format as, and the recording operation is stopped for a predetermined stop time.

Then, in step S509, the next page is fed.

Further, in this control, if the driving sources of the automatic paper feeding unit and the feeding means of the apparatus main body are different from each other or if the switching is possible even with the same driving source, the recording data of the next page is read by the prefetch of the recording buffer. Since it is possible to determine whether or not there is a paper feed, and the paper feed for the next page can be overlapped during the stop time set in step S508, when the stop time is less than the paper feed time, there is no decrease in throughput, and the stop time is the feed time. Even in the case of paper time, the stop time can be offset to some extent by the paper feed time, so that the decrease in throughput can be significantly reduced as compared with the conventional example.

In the above-described embodiment, it goes without saying that the predetermined range and the specific row are not limited to this, and the recording duty calculating means and the like are not limited to this.

Further, in the paper path in this embodiment, the control example of the upper end or the lower end of the paper in which the trouble is likely to occur is shown, but the optimum stop point can be selected according to the paper path for each model.

[Third Embodiment] In the above-described embodiment, an example in which the optimum stop time is set based on the print duty within a predetermined range is shown. However, by observing the temperature change by the diode sensor provided around the print head, Example 1
It is possible to expect the same effect as that of the above-mentioned items and 2.

That is, if the print duty is high, the energy input to the print head is large, and as a result, the temperature rise of the print head is also large. Therefore, the print duty and the temperature change of the print head are in a proportional relationship. Therefore, the print duty can be sufficiently recognized by the temperature change of the print head, and the stop time of the print operation can be controlled based on the recognized print duty.

According to this embodiment, it is possible to deal with a case where it is difficult to recognize the print duty due to the configuration of the CPU and the device.

Further, in a recording apparatus having a structure in which control for changing the response frequency of the recording head, the moving speed of the carriage, etc., is incorporated according to the temperature change of the recording head,
By integrating with this, the above control becomes possible without increasing the load of software and hardware.

[Embodiment 4] In the control in each of the above embodiments, an example is shown in which the stop time is set by using the print duty, the print time, the predetermined range, and the specific line as parameters. The stop time may change slightly depending on the conditions such as: -Recording material type-Recording material size (including paper slip direction in the case of paper).
Based on a table that also takes the above conditions into consideration, the stop time can be set more efficiently and reliably.

When two or more types of ink are used in one device, the drying time on the recording material differs depending on the composition of the ink, so a table is set for each ink.

Regarding the above-mentioned conditions, means for detecting environmental conditions by a temperature sensor / humidity sensor or the like provided in the recording apparatus, a type and size of the recording material by a detection sensor, and a printer on the host apparatus side. It is also possible by setting from the driver or setting from the DIP switch on the main body of the device.

The control described above is particularly effective in a recording apparatus that meets the following conditions.

A large-size recording apparatus that makes it more difficult to eject and stack the recording material.

· Throughput can be dramatically increased 7
Recording head with multiple nozzles of 0 or more and several kHz
A recording apparatus having a recording head corresponding to the above ejection frequencies.

A recording device capable of unconditional bidirectional recording that can dramatically increase throughput.

[0063]

As described above, according to the present invention,
By setting the recording operation stop time with the optimum timing and length, it is possible to realize stable discharge and stacking of the recording material at a low cost with almost no decrease in throughput.

[Brief description of drawings]

FIG. 1 is a plan view showing the overall configuration of a first embodiment of an inkjet recording apparatus of the present invention.

FIG. 2 is a cross-sectional view of the inkjet recording apparatus shown in FIG. 1 with an automatic paper feeding unit attached, as viewed from the side of the apparatus.

FIG. 3 is a block diagram showing the configuration of a control circuit in the first embodiment of the inkjet recording apparatus of the present invention.

FIG. 4 is a recording flowchart in the first embodiment of the inkjet recording apparatus of the present invention.

FIG. 5 is a flowchart of recording control in the first embodiment of the inkjet recording apparatus of the present invention.

FIG. 6 is a flowchart of recording control in a second embodiment of the inkjet recording apparatus of the present invention.

FIG. 7 is a cross-sectional view for explaining a jam or the like that occurs on a recording material after recording in a general inkjet recording apparatus.

FIG. 8 is a cross-sectional view for explaining a buckling state that occurs in a recording material after recording in a general inkjet recording device.

[Explanation of symbols]

 1 Recording Head 2 Carriage 3 CR Motor 4 Drive Belt 5 Carriage Axis 6 Pinch Roller 7 LF Motor 8 Pinch Roller 9 Paper Feed Roller 10 Paper Feed Motor 11 Paper Feed Stacker 12 Recording Material 13 Control Circuit 14 Recording Position 15 Sensor 24 Paper Ejection Roller 25 output stacker

Claims (12)

[Claims] 1. A recording unit that discharges ink droplets to record on a recording medium, a conveying unit that conveys the recording medium to a recording region by the recording unit, and a recording region on the recording medium. Recording time recognizing means for recognizing the time required for recording within a predetermined range, calculating means for calculating a recording duty within the predetermined range, and recognition by the recording time recognizing means at a specific line in the recording area. Recording stop control means for controlling the recording means to stop the recording operation by the recording means for a predetermined time when the required recording time and the value calculated by the calculating means are predetermined values. Inkjet recording device. 2. The ink jet recording apparatus according to claim 1, further comprising a detecting unit that detects a temperature, and the calculating unit calculates the recording duty by utilizing a temperature change of the recording unit. An inkjet recording device characterized by the above. 3. The ink jet recording apparatus according to claim 1, further comprising detection means for detecting temperature or humidity, wherein the recording stop control means uses the detection value of the detection means to stop the recording operation of the recording means. An ink jet recording apparatus, characterized in that: 4. The ink jet recording apparatus according to claim 1, wherein the recording stop control means changes the stop time of the recording operation by the recording means according to the type or size of the recording material. Inkjet recording device. 5. The ink jet recording apparatus according to claim 1, wherein the recording stop control means changes a stop time of a recording operation by the recording means according to a composition of ink ejected from the recording means onto a recording material. An inkjet recording apparatus characterized by the following. 6. The inkjet recording apparatus according to claim 1, wherein the recording unit is capable of ejecting ink onto a recording material having a width of 81 digits or more. 7. The ink jet recording apparatus according to claim 1, wherein the recording means includes a recording head having 70 or more nozzles, and ejects ink at an ejection frequency of 10 kHz or more. Inkjet recording device. 8. The ink jet recording apparatus according to claim 1, further comprising a driving unit that reciprocates a recording head of the recording unit along a direction orthogonal to a conveyance direction of the recording material, the recording unit. An ink jet recording apparatus, wherein a recording operation is performed in both forward and backward paths during the reciprocating movement by the driving means. 9. The ink jet recording apparatus according to claim 1, wherein the recording stop control means is capable of setting conditions by an input from an external host device. 10. The ink jet recording apparatus according to claim 1, wherein the recording stop control means can set conditions by an internal input means. 11. The ink jet recording apparatus according to claim 1, wherein a predetermined range within a recording area on the recording material is a lower portion by about 100 mm from an upper end of the recording material. Recording device. 12. The ink jet recording apparatus according to claim 1, wherein a predetermined range within a recording area on the recording material is an upper portion of about 100 mm from a lower end of the recording material. apparatus.