JPH064331B2 - Ink jet printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink jet printer, and more particularly to an ink jet printer including a print deviation correcting unit.

[Prior art]

An inkjet printer ejects ink droplets from an inkjet nozzle mounted on a carriage to perform dot recording on a recording paper. There are various printing methods, but in a normal case, for example, 7 dots above and below. In the case of the recording method, the dots on the first row are printed when the carriage moves in the fore direction, and the dots on the second row are printed when the carriage moves in the back direction. Is performed when the carriage moves in different directions.

On the other hand, considering the flying state of ink drops during recording,
When recording is performed during movement in the fore direction, dots have a movement component in the fore direction, and when recording is performed while moving in the back direction, ink droplets have a movement component in the back direction.

Therefore, the ink droplets fly in an oblique direction and reach the recording paper in any direction.

If the arrival position is not the same position in both the fore direction and the back direction, vertically adjacent dots are shifted left and right, and so-called print deviation occurs.

Conventionally, a structure has been adopted in which such a print deviation is visually confirmed and the print deviation is corrected by switching a switch for correcting the print deviation.

However, if such a structure is adopted, there is an advantage that the structure is simple, but it is not possible to make delicate adjustments. Therefore, when a plurality of nozzles are provided, it is necessary to correct each nozzle. The disadvantage is that the number of switches to perform is increased and the adjustment becomes more complicated.

〔Purpose〕

The present invention has been made to eliminate the above-mentioned conventional defects, and can automatically detect print deviation.
An object of the present invention is to provide an inkjet printer configured to correct print deviation according to the degree of print deviation detected.

〔Example〕

Hereinafter, the details of the present invention will be described based on the embodiments shown in the drawings.

FIG. 1 and the following figures illustrate an embodiment of the present invention.
The figure shows the structure of the print deviation detector.

In FIG. 1, reference numerals D _{0 to} D ₇ are electrodes for detection, which are wired at fine predetermined intervals, and the respective ground terminals are also wired at fine intervals.

The detection electrodes D _{0 to} D ₇ have specific addresses and are connected to the data bus of the control unit described later.

Corresponding to these detection electrodes D _{0 to} D ₇ , the Vcc electrode V ₀
˜V ₇ are arranged separated by a certain period. What is indicated by the symbol PR is a pull-down resistor.

The substrate on which these electrodes are provided is made of an ink resistant insulating material.

The print deviation detector having such a structure is attached to the printer side as shown in FIG.

In FIG. 2, reference numeral 1 denotes a recording paper, which is guided along a platen (not shown).

On the other hand, the reference numeral 2 is a carriage, which is slidably mounted in the fore direction (right direction in the drawing) and the back direction (left direction in the drawing) along a guide bar 4 which is horizontally mounted on the frame 3 of the printer. ing.

An inkjet nozzle (not shown) is attached to the carriage 2, and ink droplets are ejected by the inkjet nozzle to record dots 5.

What is indicated by reference numeral 6 is a print line.

The reference numeral 7 indicates a print deviation detector, and a print deviation detector 8 having the structure shown in FIG. 1 is provided on the surface along the print line 6. The print deviation detector 8 is set so that the print line 6 passes through the central portion between the detection electrodes D _{0 to} D ₇ and the Vcc electrodes V _{0 to} V ₇ shown in FIG.

Further, the distance between the inkjet nozzle and the print deviation detection unit 8 is equal to the distance between the inkjet nozzle and the recording paper 1.

FIG. 3 shows a block diagram of the control circuit.

In the figure, the reference numeral 9 indicates a control unit.
The storage unit 13, the timer 14, and the calculation unit 15 are controlled by the control unit 16.

The control unit 9 is connected to the print deviation detection unit 8, the inkjet nozzle 10, and the nozzle position detection circuit 11.

Next, a description will be given of the print deviation correction operation of the inkjet printer according to the present invention configured as described above.

FIG. 4 shows the arrangement of ink droplets on the print deviation detection unit 8 when print deviation occurs.

That is, in order to detect whether or not the printing deviation occurs, the carriage 2 is moved to the detecting portion 8 side to record the dot 17 while moving in the fore direction, and then the dot 18 is recorded while moving in the back direction.

Since the ink droplets have velocity components in the fore direction and the back direction at the time of recording as described above, the states of the nozzle and the carriage are changed by temperature and humidity, as shown in FIG. And will not overlap.

If the dots in the fore direction and the dots in the back direction deviate from each other in this way, printing deviation occurs.

In the case of normal printing, the dots 17 and 18 overlap.

Therefore, the control unit 9 detects and stores that the detection electrodes D _{3 to} D ₅ are turned on when the dots 17 and 18 in the fore direction and the back direction are recorded, and stores them in the memory in the storage unit 13. A value corresponding to the dot attachment position is selected from the correction value table that has been set and correction is performed.

The dot position control is performed by increasing or decreasing this delay time because the ink droplet ejection signal has a time delay with respect to the ejection position detection signal.

Specifically, so that the dots 17 and 18 are overlapped,
That is, when the number of electrodes D _{0 to} D ₇ that are turned on is the minimum and the number of electrodes in the on state is plural, the lines in the on state are necessarily adjacent to each other.

After the correction is completed in this way, the ink droplets adhering to the detection unit 8 must be wiped off and removed by some means for the next measurement.

It should be noted that the correction of the print deviation is always performed when the power switch is turned on, or only when a specific switch is pressed, or periodically after a certain period of time. Is adopted.

In the case of a multi-nozzle, it is possible to correct the print deviation for each nozzle, but in this case, one of the electrodes D _{0 to} D ₇ is determined in advance as a reference recording position. You can leave it.

〔effect〕

As is clear from the above description, according to the present invention, the recording means for ejecting ink droplets according to the recording information is reciprocally moved relative to the recording material, and the recording means is moved forward and backward respectively. In an ink-jet printer that performs a recording operation in step 2, an actual ink droplet attachment position with respect to a predetermined recording position when the recording means moves forward, and an actual ink droplet attachment position with respect to the predetermined recording position when the recording means moves forward And a correction unit that corrects the print deviation due to the reciprocating movement based on the displacement amount detected by the detection unit. Therefore, based on the actual ink droplet attachment position with respect to the predetermined recording position when the recording means moves forward and the actual ink droplet attachment position with respect to the predetermined recording position when returning, It is possible to automatically correct the print deviation during reciprocal printing based on the amount of deviation of the droplet attachment position. The recording means for ejecting ink droplets is reciprocally moved relative to the recording material. When the recording operation is performed in each of the backward movements, there is an excellent effect that it is possible to prevent the printing deviation from occurring due to the temperature and the humidity, and it is easy to always maintain the best printing state.

[Brief description of drawings]

FIG. 1 illustrates an embodiment of the present invention. FIG. 1 is a schematic configuration diagram of a print deviation detection unit, FIG. 2 is a plan view showing a main portion of a printer, FIG. 3 is a block diagram of a control circuit, and FIG. FIG. 4 is an explanatory diagram showing a state of ink droplets attached to the print deviation detection unit. DESCRIPTION OF SYMBOLS 1 ... Recording paper, 2 ... Carriage 8 ... Print deviation detection unit, 9 ... Control unit

Claims (1)

[Claims] 1. An ink-jet printer, wherein recording means for ejecting ink droplets according to recording information is reciprocally moved relative to a recording material, and recording operation is performed in each of forward movement and backward movement thereof. Based on the actual ink droplet attachment position with respect to the predetermined recording position when the recording unit moves forward and the actual ink droplet attachment position with respect to the predetermined recording position when the recording unit moves forward, An inkjet printer, comprising: a detection unit that detects a deviation amount; and a correction unit that corrects a print deviation due to the reciprocating movement based on the deviation amount detected by the detection unit.