JP2001205795A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink jet recorder in which ink dots, ejected from the nozzle array in each of a plurality of print heads arranged on a carriage while being grasped and hitting on a recording sheet, can be prevented from shifting in the X-direction. SOLUTION: A plurality of sensors 70 are arranged on a carriage 30 at the pitch of the nozzle arrays 50 in a plurality of print heads 40 arranged on the carriage 30 while being grasped. At the same time, an aligning means 90 aligns the nozzle array 50 in each of the plurality of corresponding print heads 40 the X direction based the data of the position identifying part 62 of a linear scale 60 read out by each of the plurality of sensors 70. The nozzle array 50 in each of the plurality of print heads 40 is aligned in the X direction such that each of the plurality of corresponding sensors 70 can read out the position identifying part 62A at the same part of the linear scale 60.

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 called an ink jet plotter, an ink jet printer or the like.

[0002]

2. Description of the Related Art In the above-described ink jet recording apparatus, as shown in FIG. 2, the recording paper 10 is fed on a platen 20 in the Y direction, and the carriage 30 is moved on the recording paper 10 in the feeding direction of the recording paper 10. For example, scanning is performed in a perpendicular X direction. Then, ink is ejected from a predetermined nozzle (not shown) of the print head 40 gripped by the carriage 30, and the ink lands on the recording paper 10 in a dot shape. Then, lines, figures, characters, and the like, which are made up of a collection of the dots of the ink, are drawn on the recording paper 10. As shown in FIG. 3, the print head 40 is provided with a plurality of nozzles 52 arranged at a predetermined pitch in a Y direction perpendicular to the scanning direction of the carriage 30. Make up.

In this ink jet recording apparatus, as shown in FIG. 4, a linear scale 60 is fixed to the platen 20 and provided in the X direction corresponding to the scanning direction of the carriage 30. On the carriage 30,
A sensor 70 that reads a position identification unit 62 provided on the linear scale 60 is provided. In order to clarify the operation of the sensor 70, in FIG. 4, unlike the actual one, the sensor 70 is drawn transparently. At the same time, the sensor 7
Based on the data of the position identification unit 62 of the linear scale read by 0, the alignment means 80 for performing the X-direction alignment with respect to the linear scale 60 of the nozzle row 50 of the print head 40 held by the carriage 30 includes: It is provided over the sensor 70 and the recording device main body (not shown). The positioning means 80 is composed of an electronic circuit or the like.

[0004] In this ink jet recording apparatus,
While feeding the recording paper 10 on the platen 20 in the Y direction and sending the carriage 30 in the X direction on the recording paper 10, the ink from a predetermined nozzle 52 of the nozzle row 50 of the print head 40 gripped by the carriage 30. Is injected at a predetermined timing. Then, the ink is applied to recording paper 1
0 is landed in a dot shape. Then, a line, a figure, a character, or the like formed by the collection of the dots of the ink is recorded on the recording paper 1.
It is drawn at 0.

At this time, a sensor 70 provided on the carriage 30 reads a position identification portion 62 of a predetermined portion provided on the linear scale 60 and grips the carriage 30 based on the data of the position identification portion 62. The positioning of the nozzle array 50 of the print head with respect to the linear scale 60 in the X direction is performed using the positioning means 80. Then, the ink jetted from the predetermined nozzles 52 of the nozzle row of the print head 40 at a predetermined timing is fed onto the platen 20 in the Y direction by the X of the recording paper 10.
A predetermined portion in the direction is landed in a dot shape. And
Lines, figures, characters, and the like made up of a collection of dots of ink that have landed on a predetermined portion of the recording paper 10 are drawn on the recording paper 10.

[0006] Among these recording apparatuses, an ink jet recording apparatus capable of drawing color lines, figures, characters, and the like, as shown in FIG. 4, two print heads 40 are gripped side by side in the X direction corresponding to the scanning direction of the carriage 30. Then, from a predetermined nozzle 52 of the nozzle row of each of the plurality of print heads 40, yellow,
It is configured such that inks of different colors such as magenta can be ejected. Also, in an ink jet printer recording apparatus capable of rapidly drawing monocolor lines, figures, characters, and the like, as shown in FIG. 30 are arranged side by side in the X direction corresponding to the scanning direction. The plurality of print heads 40 are configured so that ink of the same color such as black can be simultaneously ejected from predetermined nozzles 52 of the nozzle row of each of the plurality of print heads 40.

In this conventional color or monocolor ink jet recording apparatus, a sensor 70 for reading a position identification section 62 provided on a linear scale 60 is provided with a carriage 30 as shown by a solid line and a broken line in FIG. 1 in
Only one is provided. Then, the position identification sections 62 of the plurality of different portions of the linear scale 60 corresponding to the plurality of print heads 40 held by the carriage 30 are read by the single sensor 70, respectively.
Then, based on the data of the position identification unit 62 of each of the plurality of different parts, the X-direction alignment of the nozzle rows 50 of the plurality of print heads 40 held by the corresponding carriage 30 with respect to the linear scale 60 is performed. Is performed using the positioning means 80.

[0008]

However, in the above-described color or mono-color ink jet recording apparatus in which the carriage 30 is provided with only one sensor 70 for reading the linear scale position identification section 62, as described above. By collecting dots of ink ejected from predetermined nozzles 52 of a nozzle row 50 of each of the plurality of print heads 40 arranged and held on the carriage 30 at a predetermined timing and landed on the recording paper 10, color or mono-color printing is performed. When a line, figure, character, or the like is drawn on the recording paper 10, a plurality of inks of different colors or the same color landed at the same position in the X direction of the recording paper 10 constituting the line, figure, character, or the like. The position of the dot has shifted in the X direction. Then, distortion or color unevenness occurs in lines, drawings, characters, and the like, which are formed by collecting dots of a plurality of inks of different colors or the same color, drawn on the recording paper 10.

In pursuit of the cause, the following was found. As shown in FIG. 4, the nozzle row 50A of one print head of the plurality of print heads 40 held side by side on the carriage 30 indicated by the broken line is aligned with the linear scale 60 at a predetermined position in the X direction. At this time, one sensor 70 provided on the carriage 30 reads the position identification portion 62A of a predetermined portion surrounded by a broken line of the linear scale 60, and based on the data of the position identification portion 62A of the predetermined portion. The nozzle array 50A of the one print head 40 is aligned with the linear scale 60 at a predetermined position in the X direction by using the alignment means 80. Similarly, a plurality of print heads 40 gripped side by side on the same carriage 30 indicated by a solid line
When the nozzle row 50B of another print head is aligned with the linear scale 60 at the same predetermined position in the X direction as the nozzle row 50A of the one print head, the carriage 30 is also provided. With the same one sensor 70, the position identification unit 62B of the predetermined portion of the linear scale 60 surrounded by a solid line different from the above is read,
Based on the data of the position identification unit 62B of the different predetermined part, the nozzle row 50B of the other one print head 40
Is aligned with the linear scale 60 at a predetermined position in the X direction using the alignment means 80.
By the way, in many cases, the position identification unit 62 provided on the linear scale 60 has a plurality of rectangular light-shielding masks 622 and a light-transmitting mask 624, as shown in FIG.
has a structure arranged alternately at a predetermined pitch such as μm in the X direction corresponding to the scanning direction of the carriage 30;
A plurality of light shielding masks 62 arranged on the linear scale 60
There is an error in the pitch between 2 and each light-transmitting mask 624.
Therefore, the distance between the two different predetermined position identification portions 62A and 62B in which the plurality of light-shielding masks 622 and the light-transmitting masks 624 are alternately arranged in the scanning direction of the carriage 30 has an error. There is. In particular, when the position discriminating portions 62A and 62B of the two different predetermined portions are largely separated from each other by, for example, 130 mm, an error in the distance is large. As a result, based on the data of the position identification unit 62A of the predetermined portion of the linear scale 60 read by the one sensor 70, the linear scale 6
The ink dots ejected from the nozzles 52 of the nozzle row 50A of one print head 40 and held on the carriage 30 positioned at a predetermined position in the X direction with respect to 0 and landed on the recording paper 10; Same one sensor 7
On the basis of the data of the position identification unit 62B of a different predetermined part separated from the position identification unit 62A of the predetermined part of the linear scale 60 read by 0, the linear scale 60 is positioned at the same position as the predetermined position in the X direction with respect to the linear scale 60. At the position of the ink dots ejected from the nozzles 52 of the nozzle row 50B of the other print head 40 held side by side on the aligned carriage 30 and landed on the recording paper 10,
This is because a shift α in the X direction occurs.

The present invention can solve such problems.
This is to prevent a shift in the X direction from occurring at the positions of the dots of each ink jetted from the nozzles of the nozzle rows of a plurality of print heads gripped side by side on the carriage and landed at the same position in the X direction on the recording paper. It is an object of the present invention to provide an ink jet printer recording apparatus capable of performing the above.

[0011]

In order to achieve the above object, an ink jet recording apparatus according to the present invention comprises a plurality of print heads arranged and held on a carriage which scans in an X direction perpendicular to a recording paper feed direction. In an ink jet recording apparatus in which ink is ejected from predetermined nozzles of a nozzle row arranged in the Y direction perpendicular to the scanning direction of the carriage and the ink lands on the recording paper in the form of dots, the ink is fixed in the scanning direction of the carriage. A plurality of sensors for reading a linear scale provided on the linear scale and a position identification unit provided on the linear scale, wherein the carriage is aligned with a pitch in the X direction of nozzle rows of a plurality of print heads held by the carriage. A plurality of sensors arranged side by side by the number of the plurality of print heads in the scanning direction, and reading by the plurality of sensors. Positioning means for performing positioning of the nozzle row of each of the plurality of print heads gripped by the carriage with respect to the linear scale, based on the data of the position identification unit of the linear scale. It is characterized by having been provided.

In this ink jet recording apparatus,
In correspondence with each of the plurality of print heads held side by side on the carriage, a plurality of sensors corresponding to the number of the plurality of print heads are provided on the carriage by X of nozzle rows of the plurality of print heads held by the carriage. They are arranged side by side in the scanning direction of the carriage according to the pitch in the direction.
At the same time, based on the data of the position identification unit of the linear scale read by each of the plurality of sensors, the nozzle array of each of the plurality of print heads corresponding to each of the sensors is aligned with the linear scale in the X direction. , A positioning means. Accordingly, when the nozzle rows of the plurality of print heads held by the carriage are aligned at the same position in the X direction with respect to the linear scale, the plurality of print heads arranged in the carriage corresponding to the respective print heads are arranged. Each sensor reads the position identification part of the same part of the linear scale, instead of the position identification part of a different part of the linear scale. Therefore, when the nozzle rows of the plurality of print heads gripped by the carriage are aligned at the same position in the X direction with respect to the linear scale using the plurality of sensors and alignment means corresponding thereto, A shift in the X direction can be prevented from occurring at the positions of the nozzle rows of the plurality of print heads aligned with the same position in the X direction of the linear scale. As a result, the recording paper X is ejected from the nozzles of the nozzle row of each of the plurality of print heads held by the carriage.
In the position of the ink dot to land at the same position in the direction,
It is possible to prevent the displacement in the X direction from occurring.

In the ink jet recording apparatus according to the present invention, the position discriminating section is such that a plurality of light-shielding masks and light-transmitting masks are alternately arranged at a predetermined pitch in a scanning direction of the carriage on a linear scale. This is preferred.

In this ink jet recording apparatus,
With the sensor provided on the carriage, it is possible to read a position identification portion of a predetermined portion in which a plurality of linear scale light-shielding masks and light-transmitting masks are alternately arranged.

Further, in the ink jet recording apparatus of the present invention, it is preferable that the sensor is a linear encoder.

In this ink jet recording apparatus,
The position identification unit at a predetermined portion of the linear scale can be read by the sensor including the linear encoder.

[0017]

FIG. 1 shows a preferred embodiment of an ink jet recording apparatus according to the present invention, and FIG. 1 is an explanatory view of its structure. Hereinafter, the ink jet recording apparatus will be described.

In this ink jet recording apparatus,
A plurality of (two in the figure) sensors 70 for reading the position identification unit 62 provided on the linear scale 60 are provided on the carriage 30 with the nozzles of the plurality of print heads 40 held by the carriage as shown by solid lines. In accordance with the pitch P of the row 50 in the X direction, X
In the direction, a plurality (2 in FIG.
) Print heads 40 are provided side by side.
The plurality of sensors 70 have the same structure with the same shape. The plurality of sensors 70 are arranged at a predetermined pitch P in the X direction of the carriage 40 in accordance with the X direction pitch P of the nozzle rows 50 of the plurality of print heads 40 arranged and gripped in the carriage 30. , Carriage 30
And the pitch P of the plurality of sensors 70
Row 5 of a plurality of print heads 40 arranged and held
The error between the zero pitch P is set to almost zero.

The plurality of sensors 70 and the apparatus main body (not shown) correspond to the respective sensors 70 based on the data of the linear scale position identification section 62 read by the plurality of sensors 70. There is provided a positioning means 90 for performing positioning in the X direction with respect to 50 linear scales 60 of the nozzle rows of the plurality of print heads 40 held by the carriage 30. The positioning means 90 is composed of an electronic circuit or the like.

The other components are the same as those of the above-described ink jet recording apparatus shown in FIGS.

In this ink jet recording apparatus,
As shown by a solid line and a broken line in FIG.
When the nozzle row 50 of each of the plurality (two in the figure) of the print heads 40 held by the user is aligned with the linear scale 60 at the same position in the X direction, the nozzle row of each of the plurality of print heads 40 is Each of the plurality of sensors 70 arranged side by side on the carriage 30 corresponding to the position 50 reads the position identification portion 62A of the same portion of the linear scale 60, and is located at the same position in the X direction of the linear scale 60. It is possible to prevent a shift in the X direction from occurring at the positions of the nozzle rows 50 of the plurality of aligned print heads 40. Here, the pitch P in the X direction of the plurality of sensors 70 arranged side by side on the carriage 30 is equal to the pitch P in the X direction of the nozzle row 50 of the plurality of print heads 40 arranged side by side on the carriage 30 as described above. Needless to say, they are accurately adjusted, and the error of the pitch P between them is set to almost zero. As a result, a shift in the X direction occurs at the position of the ink dot ejected from the nozzle 52 of the nozzle row of each of the plurality of print heads gripped by the carriage 30 and landed on the recording paper 10 at the same position in the X direction. Can be prevented.

In the ink jet recording apparatus shown in FIG. 1, the position discriminating section 62 has a plurality of light-shielding masks 622 and light-transmitting masks 624 on the linear scale 60, as shown in FIG. It is preferable to arrange them alternately in the X direction corresponding to the scanning direction of the carriage 30.

In this case, a sensor 70 provided on the carriage 30 is used to determine the position of a predetermined portion in which a plurality of light-shielding masks 622 and light-transmitting masks 624 of the linear scale 60 are alternately arranged in the X direction. 62 can be read accurately.

In the ink jet recording apparatus shown in FIG. 1, the sensor 70 is preferably a linear encoder.

In this case, the position identification section 62 at a predetermined portion of the linear scale 60 can be accurately read by the sensor 70 composed of the linear encoder.

[0026]

As described above, according to the ink jet recording apparatus of the present invention, a plurality of print heads held side by side on a carriage are ejected from predetermined nozzles of a nozzle array to thereby obtain the same recording paper in the X direction. It is possible to reliably prevent the position of the ink dot to be landed at the position from shifting in the X direction. In addition, it is possible to accurately prevent color or monocolor lines, drawings, characters, and the like, which are composed of a collection of dots of ink that have landed on the recording paper, from causing shifts and uneven colors.

[Brief description of the drawings]

FIG. 1 is a structural explanatory view of an ink jet recording apparatus of the present invention.

FIG. 2 is a schematic configuration diagram of an inkjet recording apparatus.

FIG. 3 is a diagram illustrating the structure of a nozzle array of a print head.

FIG. 4 is a structural explanatory view of a conventional ink jet recording apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Recording paper 20 Platen 30 Carriage 40 Print head 50 Nozzle row 52 Nozzle 60 Linear scale 62, 62A, 62B Position identification part 622 Light-shielding mask 624 Translucent mask 70 Sensor 80, 90 Positioning means

Claims (3)

[Claims] 1. A method according to claim 1, wherein a plurality of print heads gripped side by side on a carriage that scans in the X direction perpendicular to the recording paper feed direction. An ink jet recording apparatus which ejects the ink and lands the ink on the recording paper in the form of dots, wherein a plurality of linear scales fixedly provided in the scanning direction of the carriage and a position identification unit provided on the linear scale are read. A plurality of sensors arranged in the scanning direction of the carriage by the number of the plurality of print heads in accordance with the pitch in the X direction of the nozzle row of the plurality of print heads held by the carriage, Based on the data of the position identification unit of the linear scale read by each of the plurality of sensors, corresponding to each of the sensors,
An ink jet recording apparatus, comprising: a positioning unit that performs positioning in the X direction of the nozzle rows of the plurality of print heads held by the carriage with respect to the linear scale. 2. The ink jet recording apparatus according to claim 1, wherein the position identification unit is configured such that a plurality of light-shielding masks and light-transmitting masks are alternately arranged at a predetermined pitch in a scanning direction of the carriage on a linear scale. apparatus. 3. The ink jet recording apparatus according to claim 1, wherein the sensor is a linear encoder.