JP2003145777A - Ink-jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of the serious dot impact position displacement in the vertical direction with respect to the medium feeding direction derived from the dot recording element hole position error in the medium feeding direction and the liquid droplet speed irregularity among the dot recording elements of the matrix type printing head in an ink-jet printer using a matrix type on- demand type multi-nozzle ink-jet head having a plurality of dot recording elements for the recording width for a recording medium. SOLUTION: The printer comprises a correcting means for correcting a mounting angle per each line recording head with dot recording elements arranged by a certain interval, an adjusting means for adjusting the mounting angle per each line recording head with the dot recording elements arranged by the certain interval while a test pattern is printed, a monitoring means for monitoring the impact displacement of the dot recording elements in the paper feeding direction by reading the test pattern, and a storing means as a memory part for storing a driving timing value corresponding to each dot recording element by quantifying amount of the dot impact displacement obtained by the monitoring means, for controlling the printing driving timing per each dot recording element.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of mounting a plurality of line recording heads in which a plurality of dot recording elements are arranged in a line at a fixed interval, and the recording head has a width corresponding to a recording width on a recording medium. The present invention relates to a matrix type on-demand type multi-nozzle inkjet head having a plurality of dot recording elements, and to an ink jet printer which performs dot recording by controlling the movement of the recording medium and controlling the driving of the dot recording elements. 2. Description of the Related Art A matrix type on-demand type multi-nozzle ink jet head having a plurality of dot recording elements for a recording width on a conventional recording medium will be described with reference to FIGS. 1, 2 and 3. FIG. Is shown. FIG. 1 shows a configuration of an ink jet printer using a matrix type on-demand type multi-nozzle ink jet head 2 having a plurality of dot recording elements for a recording width on a recording medium. The medium 4 runs under the matrix type print head 2 and prints by discharging ink from the matrix type print head 2 in accordance with the running speed of the medium. FIG. 2 shows a configuration diagram of a matrix type print head. The matrix type print head 2 comprises a plurality of line recording heads 1 in which a plurality of dot recording elements 3 are arranged in a line at regular intervals to constitute a matrix type print head 2 for the printing width of the medium 4. Media 4 of matrix type print head 2
Is defined as a Y direction, and a direction perpendicular to the traveling direction of the medium 4 is defined as an X direction. FIG. 3 shows a view of a plurality of line recording heads 1 attached. The line recording head 1 has a plurality (128) of dot recording elements 3 arranged at regular intervals, and is attached at an inclination so as to have a print resolution N (300 npi) (X direction). At this time, the interval between the dot recording elements in the medium feed direction (Y direction) is N (300 np) because all the dot recording elements are driven at one reference driving timing.
It is set to be an integral multiple of i). In the example, 300
It is set to be three times as large as npi. The dot recording element hole interval m of the line recording head 1 is determined by the printing resolution N (300
The dot recording element hole interval m is determined according to the dot recording element interval N × A (integer) (300 npi × 3) in the media feeding direction (Y direction). Conventional matrix type print head 2
Is to mount the line recording head 1 to be attached to the matrix type print head 2 with a magnifying glass and an adjusting jig so that the dot recording element hole position matches the printing resolution grid. Assembling is performed while adjusting, and the printing timing at the time of printing is the same for all dot recording elements. [0007] A plurality of line recording heads 1 in which a plurality of dot recording elements are arranged in a line at regular intervals are attached, and a plurality of dot recording elements corresponding to a recording width on a recording medium are provided. In an ink jet printer using a matrix type on-demand type multi-nozzle ink jet head, a plurality of line recording heads 1 to be mounted on a matrix type print head are mounted by using a magnifying glass and an adjusting jig, and a dot recording element hole position is correctly positioned. Therefore, there is a problem that it takes a lot of time to assemble while adjusting so that In order to solve the above-mentioned problems, according to the present invention, a plurality of line recording heads 1 in which a plurality of dot recording elements 3 are arranged in a line at regular intervals are attached to a recording medium. In an ink-jet printer that performs dot recording by controlling the movement of the recording medium and controlling the driving of the recording head with a matrix type on-demand type multi-nozzle inkjet head 2 having a plurality of dot recording elements 3 corresponding to the recording width for Correction means for correcting the mounting angle for each line recording head in which the elements are arranged at regular intervals; adjusting means for adjusting the mounting angle for each line recording head in which the dot recording elements are arranged at regular intervals while printing a test pattern; Read the test pattern and check the dot landing deviation of the dot recording element with respect to the paper feed direction. And a storage unit for storing a drive timing value corresponding to each dot recording element by quantifying the amount of dot landing deviation obtained by the monitoring unit, and a storage unit for storing a drive timing value corresponding to each dot recording element. The printing drive timing is controlled every time. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 4, a matrix type print head 2 is mounted for each line recording head 1 in accordance with each line recording head reference hole 5 and has a resolution N.
(300 npi). Each line recording head reference hole interval P is a resolution N (300 npi)
X The number of dot recording elements of the line recording head is designed to be d (128). However, an error in dimensional tolerance occurs, and an error occurs in each line recording head reference hole interval P (that is, reference hole interval P ≠ resolution N × the number d of dot recording elements of the line recording head). In an actual example, an error of ± 50 μm occurs in the XY directions. Set the line recording head 1 to the resolution N
(300 npi) when installed at an angle.
As shown in the figure, the resolution N (300 npi) + (reference hole interval P
(10.837 mm ± 50 μm) − (Resolution N (300
npi) × (the number d of dot recording elements of the line recording head)
(128)), and the reference hole interval P (10.837 mm)
± 50 μm) − (resolution N (300 npi) × (number of dot recording elements of line recording head d (128)) = ± 50
White spots and black streaks are caused by the error of μm. Therefore, as shown in FIG. 5, while performing printing, the inclination of the head is adjusted, and the dot recording element interval in the X direction is equal to each line recording head reference hole interval P (10.837 mm ± 50 μm) ÷ dot recording of the line recording head. By setting the number of elements to d (128), it is possible to eliminate white spots and black streaks. At this time, the printing head reference hole error ± 5
0 μm ÷ number of dot recording elements (128) = ± 0.391 μ
Although the position is shifted by m, it is in a state that cannot be visually recognized on printing. However, each line recording head reference hole interval P
And the line recording head reference hole 5 also has a dimensional tolerance (± 50 μm) in the Y direction, causing a shift in the dot recording element hole position in the Y direction. Since the dot recording element arrangement in the media feed direction (Y direction) is not arranged on the resolution grid, the horizontal line in the X direction cannot be printed finely as a printing result.
The correction can be made by shifting the print drive timing for each dot recording element. An embodiment according to the present invention will be described below with reference to the drawings. FIG. 9 is a block diagram showing an ink jet printer according to an embodiment of the present invention. The inkjet printer according to the present embodiment includes a controller unit 6 and a printer engine 1.
6. An operation panel 17 is provided. The controller section 6 has a configuration in which a CPU 7, a program ROM 8, an external I / F control circuit 10, a main memory 11, and an engine I / F control circuit 12 are connected to a bus 9. The operation panel 17 is connected to the CPU 7 via the I / F 18. The printer engine 16 is provided with a plurality of line recording heads 1 each having a plurality of dot recording elements arranged in a line at regular intervals as shown in FIG. 3, and as shown in FIG. The matrix type on-demand type multi-nozzle inkjet head 2 having the element 3 is configured to perform printing by moving a medium as shown in FIG. An engine control circuit 15 for controlling these operations is connected to the engine I / F control circuit 12 via the I / F 14. The external I / F control circuit 10 is connected to a host computer, a network, and the like via the I / F 13. The controller 6 stores the image data sent via the external I / F control circuit on the main memory. After the image data sent via the external I / F control circuit is accumulated for one page or more, it notifies the engine control circuit 15 of the printer engine 16 that data transmission is possible. Upon receiving the notification that data transmission is possible, the printer engine requests the controller unit 6 to transmit image data. The controller unit 6 transfers data from the main memory according to a data transmission request from the printer engine 16, and the printer engine 16 runs a medium based on the received image data and records an image with the matrix type print head 2. Do. The printer engine 16 has a driver for driving the print head. The driver will be described with reference to FIG. Although only two dot recording element driving circuits 22 are shown in FIG. 10, a plurality of dot recording element driving circuits 22 are provided so as to correspond to the number of dot recording elements 3 on a one-to-one basis.
When ejecting ink droplets, the pulse signal 19 from the signal generating circuit 24 is given to the dot recording element driving circuit 22 to turn on and off the DC voltage 23 of the voltage V1. Is applied to the dot recording element 3 to eject ink.
On the other hand, when the ink droplet is not ejected, control is performed so that the pulse signal 19 is not generated. The pulse signal 19 is controlled by a delay circuit 26 for each dot recording element 3 based on data in a dot recording element print driving timing storage section 25 for storing a print driving timing value. A print pulse is being generated. This makes it possible to control the printing timing of each dot recording element 3 and improve dot recording landing accuracy as a printing result. FIG. 2 shows an on-demand type multi-nozzle ink jet head which is a typical embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 shows a configuration of an ink jet printer using a matrix type on-demand type multi-nozzle ink jet head 2 having a plurality of dot recording elements for a recording width on a recording medium.
The medium 4 runs under the matrix type print head 2 and prints by discharging ink from the matrix type print head 2 in accordance with the running speed of the medium. FIG. 2 shows a configuration diagram of a matrix type print head. The matrix type print head 2 comprises a plurality of line recording heads 1 in which a plurality of dot recording elements 3 are arranged in a line at regular intervals to constitute a matrix type print head 2 for the printing width of the medium 4. Media 4 of matrix type print head 2
Is defined as a Y direction, and a direction perpendicular to the traveling direction of the medium 4 is defined as an X direction. FIG. 3 shows a diagram of a plurality of line recording heads 1 attached. The line recording head 1 has a plurality of (128) dot recording elements 3 arranged at a predetermined interval and attached at an angle. The matrix type print head 2 is attached to the printer shown in FIG. 1, and the inclination adjustment test pattern shown in FIG. 11 is printed. The tilt adjustment pattern is a gradation pattern from a solid portion to white in the paper feeding direction (Y direction). If the interval between the dot recording elements 3 is not appropriate in the portion of the adjacent line recording head 1 and the interval is wide,
In the case where the white streak 35 as shown in FIG. 2 is generated and the interval is small, the black streak 36 is generated and can be visually judged. Each line recording head 1 is positioned by a line recording head reference hole 5 as shown in FIG. 5, and the opposite side is sandwiched between a spring 33 and an eccentric screw 34 as shown in FIG. By rotating the eccentric screw 34, the angle of each line recording head 1 can be adjusted. During the printing of the tilt adjustment test pattern shown in FIG. 11, the tilt is adjusted by the eccentric screw 34 of each line recording head 1 so that white streaks or black streaks do not occur in the adjacent line recording heads 1. Adjust to If the adjustment of each adjacent line recording head 1 cannot be visually discriminated, the printing result is good and the tilt adjustment is completed. Next, horizontal line (X direction) 1 dot line printing is performed. FIG. 7 shows an example of the print result. The landing deviation of each dot is measured by an automatic measuring device for each dot recording element. FIG. 8 shows a list example in which the dot landing deviation amount 27 is quantified. From the dot landing deviation amount 27, a deviation time 28 when the dot recording element driving frequency of the printer is set to 20 KHz is obtained. When the driving frequency of the dot recording element is 20 KHz, the printing interval of one dot is 1 s (second) ÷ the driving frequency of the dot recording element is 20 KHz =
50 μs × 50 μs × dot landing deviation amount 27 = displacement time 28 when the dot recording element drive frequency is 20 KHz
As a result, the shift time 28 can be obtained. The shift time 28 can be input from the operation panel 17 or can be written from the personal computer to the dot recording element print recording timing storage unit 25 via the I / F 13. The offset time of each dot recording element written in the dot recording element print recording timing storage section 25 is set to a delay time setting value 29 of the delay circuit 26 of each dot recording element at the time of resetting the printer body or starting printing. When the common timing drive pulse 31 enters the delay unit 30 for each dot recording element at the time of printing, the common timing drive pulse 31 is delayed by the delay time set value 29 and the reference clock 32 and output as the print pulse 19, The printing result is close to the ideal printing result of FIG. By controlling the print drive timing for each dot recording element in this manner, the time required for assembling and adjusting the matrix type print head 2 can be shortened, and the dot recording landing accuracy can be improved. By using the ink jet printer of the present invention, the assembling adjustment time of the matrix type print head 2 can be shortened, and the dot recording landing accuracy can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of a printer according to an embodiment of the present invention. FIG. 2 is a configuration diagram of a matrix type print head of the present invention. FIG. 3 is a diagram showing a line recording head according to the present invention. FIG. 4 is an explanatory diagram between line heads of the present invention. FIG. 5 is an explanatory diagram between line heads of the present invention. FIG. 6 is an ideal printing result diagram. FIG. 7 shows an unprocessed print result. FIG. 8 is a dot shift amount list according to the embodiment of the present invention. FIG. 9 is a printer processing block diagram according to the embodiment of the present invention. FIG. 10 is a circuit diagram of a driver section in the embodiment of the present invention. FIG. 11 is a tilt adjustment test pattern according to the embodiment of the present invention. FIG. 12 is a print example of a tilt adjustment test pattern according to the embodiment of the present invention. FIG. 13 is a tilt adjustment diagram in the embodiment of the present invention. [Description of Signs] 1 ‥‥ line recording head 2 ‥‥ matrix type print head 3 ‥‥ dot recording element 4 ‥‥ media 5 ‥‥ line recording head reference hole 19 ‥‥ pulse signal 20 ‥‥ pulse voltage 22 ‥‥ dot Recording element drive circuit 23 ‥‥ DC voltage 24 ‥‥ Signal generation circuit 25 ‥‥ Dot recording element print drive timing storage section 26 ‥‥ Delay circuit 29 ‥‥ Delay time set value 30 ‥‥ Delay section 31 ‥‥ Common timing drive pulse 32 ‥‥ Reference clock 33 ‥‥ Spring 34 ネ ジ Eccentric screw 35 ‥‥ White streak 36 ‥‥ Black streak

Continuation of front page    F term (reference) 2C056 EA07 EB27 EC37 EC77 FA02                       FA13 HA08                 2C057 AF30 AF31 AF93 AG14 AK02                       AL36 AM19 AN05 AP77 AP82

Claims (1)

1. A matrix type having a plurality of line recording heads each having a plurality of dot recording elements arranged in a line at regular intervals and having a plurality of dot recording elements corresponding to a recording width on a recording medium. In an on-demand type multi-nozzle inkjet head, in an inkjet printer that performs dot recording by controlling the movement of the recording medium and controlling the driving of the dot recording element, the mounting angle is corrected for each line recording head in which dot recording elements are arranged at regular intervals. Correction means for adjusting the mounting angle for each line recording head in which the dot recording elements are arranged at regular intervals while printing the test pattern, and dot landing deviation of the dot recording element with respect to the paper feeding direction by reading the test pattern. Monitoring means for monitoring the Storage means for quantifying the amount of dot landing deviation and storing a drive timing value corresponding to each dot recording element, and controlling print drive timing for each dot recording element Printer.