JP4587424B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet printer that prints a picture or character composed of an array of a plurality of ink dots on a surface of a medium such as a sheet by ink droplets ejected from nozzles of an ink jet head.
[0002]
[Prior art]
As shown in FIGS. 3 and 4, the upper portion of the medium 30 such as a sheet on which the inkjet head 10 is mounted on the platen 20 is relatively parallel to the media 30 in the Y (lateral) direction and the X (front-back) direction. From each of the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 by moving or ejecting ink droplets from the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 toward the medium 30 at a predetermined timing. 2. Related Art Ink jet printers that make ejected ink droplets land in dots at predetermined positions on the surface of the medium 30 are well known.
According to this ink jet printer, it is possible to print a picture or character comprising an array of a plurality of ink dots on the surface of the medium 30.
Of these, the ink jet printer that moves the medium 30 on the platen 20 in the X direction and relatively moves the ink jet head 10 above the medium 30 in the X direction is called a paper moving type printer.
On the other hand, an ink jet printer in which the medium 30 is fixedly mounted on the flat platen 20 and the ink jet head 10 is moved in the X and Y directions above the medium 30 is called a flat bed type printer. .
[0003]
In the paper moving type and flat bed type inkjet printers, the inkjet head 10 is moved in the Y direction over the media 30 mounted on the platen 20 by using an electric motor 50 whose rotation is controlled by an encoder 40. ing.
More specifically, as shown in FIGS. 3 and 4, the endless belt 60 is looped around the drive pulley 62 and the driven pulley 64 so as to be able to rotate. A drive shaft 52 of an electric motor for rotating the drive pulley is connected to the drive pulley 62. The electric motor 50 is provided with an encoder 40 for controlling the rotation of the electric motor. Then, the electric motor 50 is rotated forward and backward by a predetermined angle by the encoder 40, and the endless belt 60 stretched over the driving pulley 62 and the driven pulley 64 is circulated forward and backward. Then, the inkjet head 10 supported by the endless belt 60 is made to travel forward and backward in the Y direction corresponding to the circulating direction of the endless belt 60.
[0004]
In the same Y direction as the traveling direction of the inkjet head 10, a linear scale 70 is stretched as shown in FIG. The linear scale 70 is formed of a transparent polyester film or the like in the form of a strip, and on the linear scale 70, for example, a large number of linear scales 72 are arranged side by side at a pitch of 720 dpi and are photo-printed.
A linear scale sensor 80 is integrally attached to the head frame 14 that supports the inkjet head 10 on the endless belt 60. As shown in FIG. 4, the linear scale sensor 80 is moved in the Y direction along the linear scale 70 so as to straddle the linear scale 70. Then, by the linear scale sensor 80 including the light emitting element 82 and the light receiving element 84 provided so as to sandwich the linear scale 70, the traveling position in the Y direction of the inkjet head 10 that travels in the Y direction integrally with the linear scale sensor 80 is determined. Reading is made from a scale 72 engraved on a transparent linear scale 70.
[0005]
In the ink jet printer shown in FIGS. 3 and 4, the endless belt 60 can be circulated using the electric motor 50 whose rotation is controlled by the encoder 40. And the inkjet head 10 supported by the endless belt 60 can be run in the Y direction.
At that time, the scale 72 engraved on the linear scale 70 stretched in the Y direction, which is the same as the traveling direction of the inkjet head 10, of the traveling position of the inkjet head 10 in the Y direction is integrated with the inkjet head 10. This can be detected by reading from the linear scale sensor 80 traveling in the direction. Then, based on the detected traveling position data of the inkjet head 10 in the Y direction, from the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 according to the picture or character data input to the host computer or the like for driving the inkjet printer. Ink droplets can be ejected at a predetermined timing. Then, with the ink droplets, a picture or character composed of an array of a plurality of ink dots can be printed on the surface of the medium 30.
[0006]
[Problems to be solved by the invention]
However, the scale 72 of the linear scale 70 is read by the linear scale sensor 80 to detect the traveling position of the inkjet head 10 in the Y direction, and based on the detected traveling position data of the inkjet head 10 in the Y direction, When ink droplets are ejected from the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 at a predetermined timing in accordance with the character data, from the arrangement of a plurality of ink dots printed on the surface of the medium 30 by the ink droplets. The length in the Y direction of the resulting picture or character has become longer or shorter than the length in the Y direction of the picture or character to be printed from the picture or character data using the inkjet printer.
For this reason, it has been impossible to print a small poster picture for a large poster combination, an original drawing for a printing plate, or the like that requires accurate accuracy with the above-described ink jet printer.
[0007]
The reason is that the linear scale 70 made of polyester film or the like expands and contracts in the Y direction depending on the weather conditions around it.
Specifically, for example, when the linear scale 70 is formed of a polyester film, the expansion / contraction ratio α with respect to the temperature of the linear scale 70 is 0.001% / ° C., and the expansion / contraction ratio α with respect to the humidity of the linear scale 70 is. Becomes 0.001% /% RH.
Therefore, when the temperature around the linear scale 70 formed from the polyester film increases by 30 ° C., the elongation per 150 mm of the linear scale 70 becomes 45 μm. Further, when the humidity around the linear scale 70 formed from the polyester film increases by 60%, the elongation per 150 mm of the linear scale 70 becomes 90 μm.
As a result, traveling position data in the Y direction of the inkjet head 10 read by the linear scale sensor 80 from a scale 72 engraved on the linear scale 70 placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity. This is because crazy will occur.
[0008]
The present invention has been made to solve such a problem, and even if the linear scale expands and contracts in the Y direction with changes in the surrounding temperature and humidity, it is not affected by it. Ink droplets ejected from the nozzles of the inkjet head at a predetermined timing in accordance with the Y-direction position of the picture or character to be printed from the character data using the inkjet printer without any deviation in the Y-direction. An object of the present invention is to provide an ink jet printer that can be landed accurately.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a first inkjet printer of the present invention has a structure in which an inkjet head travels in the Y direction using an electric motor whose rotation is controlled by an encoder, and is a small poster picture or printing for a large poster combination. An ink jet printer that prints an original drawing for a plate , wherein a scale engraved on a linear scale in which the traveling position of the ink jet head in the Y direction is stretched in the same Y direction as the traveling direction of the ink jet head is integrated with the ink jet head Detected by reading with a linear scale sensor that travels in the Y direction, and based on the detected traveling position data in the Y direction of the inkjet head, ink droplets are ejected from the nozzles of the inkjet head at a predetermined timing according to picture or character data. Structure in In the jet printer, when the electric motor is rotated by a predetermined angle by the encoder, the actual travel distance A in which the inkjet head actually traveled in the Y direction calculated from the rotation angle of the electric motor rotated by the encoder, and the predetermined weather A calculating means for calculating a ratio R with a measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from a scale engraved on a linear scale placed under conditions; and the calculation means calculated by the calculating means Based on the ratio R, the measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale of the linear scale placed under the predetermined weather condition matches the actual travel distance A in the Y direction of the inkjet head. Correction means for correcting the Based on the travel position data in the Y direction of the inkjet head obtained by correcting the measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale engraved on the scale, the drawing or character data And an ink ejecting means for ejecting ink droplets from the nozzles of the ink jet head at a predetermined timing.
[0010]
In the first ink jet printer, when the electric motor is rotated by a predetermined angle by the encoder and the ink jet head travels in the Y direction, the actual travel distance A that the ink jet head actually traveled in the Y direction is It can always be accurately calculated from the rotation angle of the electric motor rotated by an encoder that is not affected by changes in temperature and humidity. At the same time, the measured travel distance B in the Y direction of the inkjet head at that time is subjected to predetermined weather conditions that expand and contract with changes in ambient temperature and humidity by a linear scale sensor that travels in the Y direction integrally with the inkjet head. It can be read from the scale engraved on the placed linear scale. Then, the ratio R between the actual travel distance A and the measured travel distance B can be calculated by the calculation means. Based on the ratio R, the measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale of the linear scale placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity, Correction can be made so as to match the actual travel distance A in the Y direction of the inkjet head. And a correction means for the measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale engraved on the linear scale placed under a predetermined weather condition that expands and contracts with changes in ambient temperature and humidity Ink droplets are ejected from the nozzles of the inkjet head at a predetermined timing by the ink ejecting means according to the picture or character data based on the accurate traveling position data in the Y direction of the inkjet head obtained by correcting the ink. Drops can be landed accurately at a desired position on the surface of the media without shifting in the Y direction. And the length of the Y direction is Y direction of the picture or character to be printed from the picture or character data by using the ink jet printer by the ink droplets that have landed accurately at the desired position on the surface of the medium without deviation in the Y direction. It is possible to print on the surface of the medium with high accuracy a picture or character comprising an array of a plurality of ink dots having the same length as that of the ink.
[0011]
According to a second ink jet printer of the present invention, in the first ink jet head printer of the present invention, instead of the correcting means, a picture or character to be printed using an ink jet printer from a picture or character data is calculated by the calculating means. Is provided with a correction device for generating a corrected picture or character data enlarged or reduced in the Y direction by the ratio R of the actual travel distance A to the measured travel distance B calculated by In accordance with correction picture or character data created by the correction device, based on the running position data in the Y direction of the inkjet head read by the linear scale sensor from the scale engraved on the linear scale placed under the predetermined weather condition Ink droplets from the nozzles of the inkjet head at a specified timing It is characterized by an ink jet device that Isa is provided.
[0012]
In the second ink jet printer, a correction device is used to cause a picture or character to be printed from the picture or character data using the ink jet printer to expand and contract as the ambient temperature and humidity change. The ratio R of the actual actual travel distance A in the Y direction of the ink-jet head to the measured travel distance B in the Y-direction of the ink-jet head read by the linear scale sensor from the scale of the linear scale placed on A reduced correction picture or character data can be created. The Y of the inkjet head read by the linear scale sensor from the scale of the linear scale placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity according to the corrected pictorial image or character data created by the correction device Based on the traveling position data in the direction, the ink ejection device can eject ink droplets from the nozzles of the inkjet head at a predetermined timing. Then, the ink droplets are corrected according to the correction picture or character data created by the correction device according to the expansion / contraction state of the linear scale placed under the predetermined weather condition that expands and contracts with changes in ambient temperature and humidity. It is possible to land accurately on a desired position on the surface of the medium to be landed based on the previous picture or character data without any deviation in the Y direction. Then, the ink droplets that have landed accurately at the desired position on the surface of the media without shifting in the Y direction, the length in the Y direction is Y of the picture or character to be printed using the ink jet printer from the picture or character data. It is possible to print a picture or character comprising an array of a plurality of ink dots having the same length as the direction length on the medium surface with high accuracy.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a preferred embodiment of the first ink jet printer of the present invention, and FIG. 1 is a front view showing a schematic structure thereof. The first ink jet printer will be described below.
[0014]
In the first ink jet printer, the electric motor 50 that causes the ink jet head 10 to travel in the Y direction is connected to the encoder 40 from the rotation angle of the electric motor 50 that is rotated by the encoder 40 when the electric motor 50 is rotated by a predetermined angle by the encoder 40. The actual travel distance A where the inkjet head 10 actually traveled in the Y direction calculated by an electronic circuit (not shown) or the like was placed under predetermined weather conditions that expand and contract with changes in ambient temperature and humidity. The measured travel distance B in the Y direction of the inkjet head 10 read by an electronic circuit (not shown) connected to a linear scale sensor 80 that travels integrally with the inkjet head 10 from the scale 72 engraved on the linear scale 70. A calculation means 100 for calculating the ratio R is provided. The calculating means 100 is formed from an electronic circuit or the like.
Further, based on the ratio R between the actual travel distance A and the measured travel distance B calculated by the calculation means 100, the scale 72 of the linear scale placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity. Correction means 110 for correcting the measured travel distance B in the Y direction of the inkjet head 10 read by the linear scale sensor 80 that travels integrally with the inkjet head 10 so as to match the actual travel distance A in the Y direction of the inkjet head 10. Is provided. The correction means 110 is formed from an electronic circuit or the like.
Further, the correction means 110 calculates the measured travel distance B in the Y direction of the inkjet head 10 read by the linear scale sensor 80 that travels integrally with the inkjet head 10 from the scale 72 engraved on the linear scale 70 placed under predetermined weather conditions. Ink ejection for ejecting ink droplets at a predetermined timing from a plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 in accordance with a picture or character data based on the Y-direction running position data of the inkjet head 10 obtained by the correction Means 120 are provided. The ink ejecting means 120 is formed from an electronic circuit or the like.
[0015]
The rest of the configuration is the same as that of the above-described inkjet printer shown in FIGS.
In the first ink jet printer, when the electric motor 50 is rotated by a predetermined angle by the encoder 40 and the ink jet head 10 travels in the Y direction, the actual travel distance that the ink jet head 10 actually travels in the Y direction. A can always be accurately calculated by an electronic circuit or the like connected to the encoder 40 from the rotation angle of the electric motor 50 rotated by the encoder 40 that is not affected by changes in ambient temperature and humidity. At the same time, the measured travel distance B in the Y direction of the inkjet head 10 at that time is changed by the electronic circuit or the like connected to the linear scale sensor 80 that travels integrally with the inkjet head 10 according to changes in ambient temperature and humidity. It can be read from a scale 72 engraved on a linear scale 70 placed under predetermined weather conditions that expand and contract. Then, the ratio R between the actual travel distance A and the measured travel distance B can be calculated by the calculation means 100. Based on the ratio R, the measured travel distance in the Y direction of the inkjet head 10 read by the linear scale sensor 80 from the scale 72 of the linear scale placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity. B can be corrected by the correcting unit 110 so as to match the actual traveling distance A in the Y direction of the inkjet head 10. Then, based on the accurate traveling position data in the Y direction of the inkjet head 10 obtained by correcting the measured traveling distance B in the Y direction of the inkjet head 10 by the correcting unit 110, the ink ejecting unit 120 is used in accordance with the picture or character data. Thus, ink droplets ejected from the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 at a predetermined timing can be accurately landed on the desired position on the surface of the medium 30 without deviation in the Y direction. The length in the Y direction is the same as the length in the Y direction of the picture or character to be printed from the picture or character data using the inkjet printer. It is possible to print a picture or character comprising an array on the surface of the medium 30 with high accuracy.
[0016]
FIG. 2 shows a preferred embodiment of the second ink jet printer of the present invention, and FIG. 2 is a front view showing a schematic structure thereof. The second ink jet printer will be described below.
[0017]
This second ink jet printer replaces the correction means 110 with an ink jet for a measured travel distance B calculated by the calculating means 100 for a picture or character to be printed from the picture or character data using the ink jet printer. A correction device 112 is provided that creates a correction picture or character data enlarged or reduced in the Y direction by the ratio R (= A / B) of the actual actual travel distance A in the Y direction of the head 10. The correction device 112 is a program software for creating picture or character data incorporated in a host computer or the like for driving an ink jet printer, and Y for the picture or character to be printed from the picture or character data using the ink jet printer. It is formed from program software capable of creating a corrected picture or character data in which the length in the direction is appropriately enlarged or reduced, and an electronic circuit or the like.
At the same time, instead of the ink ejecting means 120, the linear scale sensor 80 reads from the scale 72 engraved on the linear scale 70 placed under a predetermined weather condition in accordance with the correction picture or character data created by the correction device 112. An ink ejecting device 122 that ejects ink droplets from a plurality of nozzles 12 arranged on the lower surface of the ink jet head 10 at a predetermined timing based on the traveling position data of the ink jet head 10 in the Y direction is provided. The ink ejecting device 122 is formed from an electronic circuit or the like.
[0018]
Others are the same as those of the first ink jet printer shown in FIG.
In the second ink jet printer, a predetermined weather condition in which the correction device 112 is used to expand or contract the picture or character to be printed from the picture or character data using the ink jet printer as the ambient temperature or humidity changes. The ratio R of the actual actual travel distance A in the Y direction of the inkjet head 10 to the measured travel distance B in the Y direction of the inkjet head 10 read by the linear scale sensor 80 from the scale 72 of the linear scale placed below, A corrected picture or character data enlarged or reduced in the Y direction can be created. The linear scale sensor 80 reads from the scale 72 of the linear scale placed under predetermined weather conditions that expands and contracts with changes in ambient temperature and humidity in accordance with the corrected pictorial image or character data created by the correction device 112. Based on the traveling position data of the inkjet head 10 in the Y direction, the ink ejection device 122 can eject ink droplets from the plurality of nozzles 12 arranged on the lower surface of the inkjet head 10 at a predetermined timing. Then, according to the correction picture or character data created by the correction device 112 in accordance with the expansion / contraction state of the linear scale 70 placed under a predetermined weather condition in which the ink droplet expands and contracts with changes in ambient temperature and humidity. Thus, it is possible to accurately land on the desired position on the surface of the medium 30 to be landed on the basis of the uncorrected picture or character data without any deviation in the Y direction. The length of the Y direction of the image or character data to be printed using the ink jet printer from the image or character data by the ink droplets that have landed accurately on the surface of the medium 30 without deviation in the Y direction. It is possible to print on the surface of the medium 30 with high accuracy a picture or character comprising an array of a plurality of ink dots having the same length as the direction.
[0019]
【The invention's effect】
As described above, according to the first or second ink jet printer of the present invention, even if the linear scale formed from a polyester film expands or contracts with changes in the surrounding temperature or humidity, it affects it. Instead, the ink droplets ejected from each of the plurality of nozzles arranged on the lower surface of the ink jet head at a predetermined timing are matched with the position of the picture or character to be printed from the picture or character data using the ink jet printer, and the surface of the media. Can be landed accurately at the desired position without any deviation in the Y direction. Then, with the ink droplets, the length of the Y direction is a picture to be printed from the picture or character data by using an ink jet printer, or the picture made of an array of a plurality of ink dots having the same length as the length of the character in the Y direction. Or, characters can be printed on the media surface with high accuracy.
As a result, if the first or second ink jet printer of the present invention is used, it is possible to print a small poster picture for a large poster combination, an original drawing for a printing plate, and the like that require accurate accuracy.
[Brief description of the drawings]
FIG. 1 is a front view showing a schematic structure of a first ink jet printer of the present invention.
FIG. 2 is a front view showing a schematic structure of a second ink jet printer of the present invention.
FIG. 3 is a front view showing a schematic structure of a conventional ink jet printer.
FIG. 4 is a plan view showing a schematic structure of a conventional inkjet printer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Inkjet head 12 Nozzle 20 Platen 30 Media 40 Encoder 50 Electric motor 60 Endless belt 62 Drive pulley 64 Driven pulley 70 Linear scale 72 Scale scaled on linear scale 80 Linear scale sensor 100 Calculation means 110 Correction means 112 Correction device 120 Ink ejection Means 122 Ink Ejecting Device

Claims (2)

An inkjet printer that prints a small poster picture for a large poster combination or an original drawing for a printing plate with a structure in which the inkjet head is driven in the Y direction using an electric motor whose rotation is controlled by an encoder,
Detecting the running position of the inkjet head in the Y direction by reading a scale engraved on a linear scale stretched in the same Y direction as that of the inkjet head with a linear scale sensor that runs in the Y direction integrally with the inkjet head Then, based on the detected traveling position data of the inkjet head in the Y direction, according to a picture or character data, an inkjet printer having a structure for ejecting ink droplets from the nozzle of the inkjet head at a predetermined timing,
When the electric motor is rotated by a predetermined angle by the encoder, the inkjet head actually traveled in the Y direction calculated from the rotation angle of the electric motor rotated by the encoder is placed under a predetermined weather condition. Based on the ratio R calculated by the calculation means, the calculation means for calculating the ratio R with the measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale engraved on the linear scale The measured travel distance B in the Y direction of the inkjet head read by the linear scale sensor from the scale of the linear scale placed under the predetermined weather condition is corrected so as to match the actual travel distance A in the Y direction of the inkjet head. From the correction means and the scale engraved on the linear scale placed under the predetermined weather conditions Based on the traveling position data in the Y direction of the inkjet head obtained by correcting the measured traveling distance B in the Y direction of the inkjet head read by the near scale sensor by the correcting means, from the nozzles of the inkjet head according to the picture or character data. An ink jet printer comprising ink ejecting means for ejecting ink droplets at a predetermined timing.   Instead of the correction means, the picture or character to be printed from the picture or character data using the ink jet printer, the ratio R of the actual travel distance A to the measured travel distance B calculated by the calculation means, A correction device for generating corrected picture or character data enlarged or reduced in the Y direction is provided, and instead of the ink ejecting means, according to the corrected picture or character data generated by the correction device, the predetermined weather condition An ink ejecting device for ejecting ink droplets from the nozzles of the ink jet head at a predetermined timing is provided based on the Y position traveling position data of the ink jet head read by the linear scale sensor from the scale engraved on the linear scale placed on 2. An ink jet printer according to claim 1, wherein

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