JPH11254759A - Recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the vibration of a recording device by minimizing the counterforce and the angular moment generated in the middle of the increase and decrease of the speed of carriages. SOLUTION: A recording device is provided with three carriages 4, 5 and 6 moving reciprocatingly in parallel one another and driving sections 7, 8 and 9 driving respective three carriages. The carriages 4, 5 and 6 are provided with ink jet heads 1, 2 and 3, and the carriages 4, 5 and 6 are so driven by the driving sections 7, 8 and 9 as to minimize the total sum of counterforce generated by driving the carriages 4, 5 and 6. The carriages 4, 5 and 6 are so disposed as to minimize the moment around an optional point during driving the carriages 4, 5 and 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus, and more particularly to a printing apparatus which performs printing by reciprocating an ink jet head in a main scanning direction.

[0002]

2. Description of the Related Art Conventionally, a recording apparatus such as an ink jet printer has been known. In general, a head for ejecting ink from a plurality of nozzles is main-scanned in a digit direction of a recording sheet (a direction crossing the recording sheet). It is recorded by. FIG. 14 is a perspective view showing a schematic configuration of a conventional ink jet printer. In the drawings, the same reference numerals indicate the same or corresponding members.

The ink jet printer includes a recording sheet 17, which is a recording medium such as a sheet of paper or a plastic thin plate, an ink jet head 1 of an ink jet system, a carriage 4 for holding the ink jet head 1, and a carriage 4 on the recording surface of the recording sheet 17. Sliding shafts 10 and 11 for reciprocating in parallel and a carriage 1
A driving unit 7 for reciprocating driving along 0, 11;
A timing belt 12 for changing the rotation of the carriage into a reciprocating motion of the carriage, and an idle pulley 13.

In addition, the ink jet printer has a guide plate 14A for guiding the recording sheet 17 along a conveying path.
And a feed roller 15 for discharging the recording sheet 17.

The inkjet head 1 uses a piezoelectric element (PZT). A voltage is applied to the piezoelectric element, causing distortion. This distortion changes the volume of the channel filled with ink. Due to this change in volume, ink is ejected from nozzles provided in the channel,
Recording on the recording sheet 17 is performed.

The carriage 4 performs a main scan of the recording sheet 17 in the traverse direction (a direction traversing the recording sheet 17) by the drive unit 7, the idle pulley 13, and the timing belt 12, and the ink jet head 1 mounted on the carriage 4 An image for one line is recorded. Each time recording of one line is completed, the recording sheet 17 is fed in the vertical direction and is sub-scanned to record the next line.

[0007] The recording sheet 17 that has passed through the recording section is discharged by a feed roller 15 disposed on the downstream side in the transport direction.

In the ink-jet printer thus configured, the ink-jet head 1 is reciprocated by the carriage 4, so that the ink-jet head 1 is inverted at both ends of the recording sheet. Further, in recent years, a higher recording speed has been pursued, and it is desired that the inkjet head 1 be reversed as quickly as possible. This necessarily gives a sudden acceleration, and the ink jet printer receives a reaction force generated by the sudden acceleration of the ink jet head 1. Furthermore, a rotational moment is generated by this reaction force,
Subject to rotating force. The reaction force and the rotational moment generate a large vibration in the ink jet printer. In order to improve the recording quality by making the operation of the mechanical part of the recording apparatus accurate, it is necessary to eliminate this vibration.

An ink jet printer that absorbs vibration caused by a reaction force to prevent the vibration is disclosed in Japanese Patent Application Laid-Open No. 8-276577. This ink jet printer includes two ink jet heads each having a plurality of nozzles for discharging ink arranged therein, and reciprocates the two ink jet heads in exactly opposite phases. According to this inkjet head, while the inkjet head is accelerating or decelerating, one of the inkjet heads moves in the opposite direction to the acceleration of the other inkjet head and has the same magnitude of acceleration. The reaction force F generated when the ink jet head accelerates / decelerates is represented by the product of the acceleration a and the mass m. Therefore, if the mass of one ink jet head is equal to the mass of the other ink jet head, the sum of the reaction forces is zero. . Therefore, the vibration of the ink jet printer main body due to the reaction force generated during the acceleration and deceleration of the ink jet head is reduced.

[0010]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open No. Hei 8-2
In the ink jet printer described in Japanese Patent No. 76577, vibration caused by a reaction force generated during acceleration and deceleration of the ink jet head is reduced, but since the reaction forces are applied to the ink jet printer main body in opposite directions, a rotational moment (couple) is generated. However, the main body of the inkjet printer vibrates due to the rotational moment.

As the recording speed increases, the acceleration increases and the reaction force increases, so that the vibration of the ink jet printer body also increases.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to minimize a reaction force and a rotating moment generated during acceleration and deceleration of a carriage, and to provide a recording apparatus with less vibration. It is to provide.

It is still another object of the present invention to provide a smaller and lighter recording apparatus with less vibration by using a single driving unit for driving the ink jet head.

It is still another object of the present invention to provide a recording apparatus in which a large amount of black ink or photo ink is mounted on a heavy-weight carriage to reduce the difference in weight between the carriages and further reduce vibration. .

It is another object of the present invention to provide a recording apparatus in which black ink and yellow ink are mounted on a heavy-weight carriage to eliminate a difference in weight between carriages when color recording is large, and to further reduce vibration. And

Further, the same color ink is mounted on all the carriages, and the same amount of ink is consumed in each carriage, so that there is no difference in weight between carriages, and a recording apparatus with less vibration is provided. With the goal.

It is still another object of the present invention to provide a recording apparatus in which inks of different colors are mounted on each of the carriages to increase the recording speed, prevent color mixing, and further improve the recording quality.

Another object of the present invention is to provide a recording apparatus in which the center of gravity of a plurality of carriages is made one to minimize a reaction force generated during acceleration and deceleration of the carriage, and a vibration is reduced by not generating a rotational moment. That is.

According to an aspect of the present invention, there are provided at least three carriages reciprocating in parallel with each other, and a drive unit for driving each of the at least three carriages, wherein at least one of the at least three carriages includes:
An inkjet head is provided, and the driving unit has at least 3
The at least three carriages are driven such that the sum of the reaction forces generated by the driving of the three carriages is minimized, and the carriages are arranged such that the moment around any one point during the driving of the at least three carriages is minimized. It is characterized by having been done.

According to the present invention, it is possible to provide a recording apparatus in which the reaction force and the rotational moment generated during the acceleration and deceleration of the carriage are minimized and the vibration is small.

More preferably, there is one drive unit,
At least three carriages are coupled to the transmission, and the drive is configured to drive at least three of the carriages by driving the transmission.
One carriage is driven.

According to the present invention, it is possible to provide a recording apparatus which is further reduced in size and weight and has less vibration.

More preferably, among the at least three carriages, a carriage having a large weight is loaded with black ink or photo ink.

According to the present invention, it is possible to eliminate the difference in weight between carriages and to provide a recording apparatus with less vibration.

More preferably, among the at least three carriages, a carriage having a large weight is equipped with black ink and yellow ink.

According to the present invention, it is possible to provide a recording apparatus in which the difference in weight between carriages is reduced when there are many color recordings, and vibration is further reduced.

[0027] More preferably, at least three carriages are loaded with ink of the same color.

According to the present invention, it is possible to provide a recording apparatus in which the difference in weight between carriages is reduced and the vibration is further reduced by setting the same amount of ink consumption in each carriage.

[0029] More preferably, at least three carriages are loaded with inks of different colors.

According to the present invention, it is possible to provide a recording apparatus capable of increasing the recording speed, preventing color mixing, and further improving the recording quality.

According to another aspect of the present invention, there are provided at least two carriages reciprocating in parallel with each other, and a drive unit for driving each of the at least two carriages, and at least one of the at least two carriages has an ink jet head. The center of gravity of each of the at least two carriages is on a single straight line parallel to the direction of movement of the at least two carriages, and the driving unit minimizes the total reaction force generated by driving the at least two carriages. And at least two carriages are driven.

According to the present invention, it is possible to provide a recording apparatus in which the center of gravity of a plurality of carriages is made one, the reaction force generated during acceleration and deceleration of the carriage is minimized, and no vibration is generated by generating no rotational moment. .

[0033]

Embodiments of the present invention will be described below. In the drawings, the same reference numerals indicate the same or corresponding members.

[First Embodiment] FIG. 1 is a perspective view showing a part of a recording apparatus according to a first embodiment. The recording device includes three inkjet heads 1, 2, 3,
An ink tank (small) 18 for supplying ink to the inkjet heads 1 and 3, an ink tank (large) 19 for supplying ink to the inkjet head 2, and the ink tanks 1 and 3 and an ink tank (small) 18 are held. Carriages 4 and 6, a carriage 5 for holding the inkjet head 2 and an ink tank (large) 19,
Sliding shafts 10, 11 for reciprocating the carriages 4, 5, 6 in parallel with the recording surface of the recording sheet 17, and a driving unit for reciprocating the carriages 4, 5, 6 along the sliding shafts 10, 11. 7, 8, 9 and a timing belt 12 for changing the rotation of the drive units 7, 8, 9 into a reciprocating motion of the carriage.
And an idle pulley 13.

As the recording sheet 17, a recording medium such as paper or a plastic thin plate is used. In addition, the recording device,
It includes a guide belt 14 for guiding the recording sheet 17 along the transport path, and a feed roller 15 for feeding the guide belt 14.

The carriages 4, 5, and 6 include driving units 7, 8,
9, idle pulley 13, and timing belt 12
, The main scan of the recording sheet 17 is performed in the digit direction (the direction traversing the recording sheet 17), and the ink jet heads 1, 2, and 3 attached to the carriages 4, 5, and 6 each move 1
Record the image for the line. Each time the recording of one line of image is completed by each of the inkjet heads 1, 2, and 3, the recording sheet 17 is fed in the vertical direction and is sub-scanned to record the next line. Inkjet heads 1, 3
, An ink tank (small) 18 is attached to the inkjet head 2, and an ink tank (large) 19 is attached to the inkjet head 2. Two ink tanks (small) 18
Three color inks of yellow, magenta, and cyan are stored in an ink tank (large) 19, and the recording apparatus can perform full-color recording.

The weight carried by the carriage 1, that is, the total weight of the carriage's own weight and the weight of the ink jet head 1 and the ink tank (small) 18 is calculated by the carriage 3
Is the same as the weight carried by the carriage 2, which is half the weight carried by the carriage 2. Therefore, the ink tank (large) 1
9 can store approximately twice as much ink as the ink tank (small) 18. The ink tank (small) 1
8 and the amount of ink remaining in the ink tank (large) 19, the weight carried by the carriages 1, 2, and 3 has some fluctuation, but the fluctuation is 10% or less.

On the recording sheet 17, full-color information is recorded in this manner. Thereafter, the recording sheet 17 is discharged out of the recording apparatus by a feed roller 15 driven by a feed motor.

FIG. 2 is a block diagram showing a schematic configuration of a control unit of the printing apparatus according to the first embodiment. In the figure, a main controller 21 receives a signal such as image data from a host computer 20. When recording on the recording sheet 17, the main controller 21
The feed motor is driven and controlled through a motor driver A26 to feed the recording sheet 17 one line at a time, and the carriages 4, 5, and 6 are main-scanned by controlling the drive units 7, 8, and 9 through a motor driver B27. In addition, the main controller 21 receives a signal of the image data received from the host computer 20 and operates the driver controller 2 based on the signal.
2 and output control of the ejection signals of the inkjet heads 1, 2, 3 via the head drivers 23, 24, 25.

FIG. 3 to FIG.
It is a figure for explaining composition of 2 and 3. FIG. 3 is a plan view showing a part of the surface of the inkjet heads 1, 2, and 3 having nozzles. FIG. 4 is a cross-sectional view taken along line AA of FIG. 3, and FIG. It is a line sectional view.

The ink jet heads 1, 2, and 3 have a structure in which a nozzle plate 51, a partition wall 52, a vibration plate 53, and a substrate 54 are integrally laminated.

The nozzle plate 51 is made of metal or synthetic resin, has nozzles 55, and has an ink-repellent layer on the surface. A thin film is used for the partition 52, and is fixed between the nozzle plate 51 and the diaphragm 53.

A plurality of ink channels 56 for accommodating ink are provided between the nozzle plate 51 and the partition 52.
, A common ink chamber 57, and an inlet 58 connecting each ink channel 56 to the common ink chamber 57. The common ink chamber 57 includes an ink tank (small) 1
8 or an ink tank (large) 19,
The ink in the common ink chamber 57 is supplied to the ink channel 56.

Each ink channel 56 is provided in the vibration plate 53.
And a plurality of driving piezoelectric elements 61 corresponding to. The processing of the diaphragm 53 is performed by first fixing the diaphragm 53 to a substrate 54 having a wiring portion 64 with an insulating adhesive, and then forming a separate groove 63 by dicer processing and dividing the diaphragm 53. . Further, by this division, the driving piezoelectric elements 61 corresponding to the respective ink channels 56 are formed.
And the piezoelectric element column 62 located between the adjacent driving piezoelectric elements 61 are separated.

The wiring portion 64 on the substrate 54 includes a common electrode 59 commonly connected to all the driving piezoelectric elements 61 in the ink jet heads 1, 2, and 3 and a driving electrode in each of the ink jet heads 1, 2, and 3. And the individual electrodes 60 individually connected to the piezoelectric element 61 for use. The common electrode 59 is connected to the ground, and the individual electrodes 60 are connected to the head drivers 23, 24,
25. The operations of the ink jet heads 1, 2, and 3 having such a configuration are controlled by a control unit of the printing apparatus. Head driver 23, 2 of control unit
A predetermined voltage, which is a printing signal, is applied between the common electrode 59 and the individual electrode 60 from the electrodes 4 and 25 (see FIG. 2), and the driving piezoelectric element 61 is deformed in the direction of pressing the partition wall 52. The deformation of the driving piezoelectric element 61 is transmitted to the partition wall 52, whereby the ink in the ink channel 56 is pressurized, and the ink drop is formed via the nozzle 55 by the ink drop on the recording sheet 17 (FIG. 1).
See).

Next, the acceleration / deceleration of the carriage, and the reaction force and rotational moment generated thereby will be described.

FIG. 6 is a schematic diagram showing the positional relationship between the carriages 4, 5, and 6 for explaining the acceleration and deceleration of the carriages 4, 5, and 6. The carriages 4, 5, and 6 are provided with sliding shafts 10, 11 so as to perform main scanning in parallel. A distance L between the carriage 4 and the carriage 5;
The distance L between the carriage 5 and the carriage 6 is the same. The weight carried by the carriage 4 is the total weight of the weight of the carriage 4, the weight of the ink jet head 1, and the weight of the ink tank (small size) 18 (hereinafter referred to as the weight m _{1 of the} carriage 4; The weight is referred to as the weight m ₂ of the carriage 5 and the weight carried by the carriage 6 is referred to as the weight m _{3 of the} carriage 6). Weight of carriage 4 m
₁ is the same as the weight m ₃ of the carriage 6 and is half of the weight m ₂ of the carriage 6, so that m ₂ = 2 m ₁ = 2 m ₃ .

The initial positions of the carriages 4, 5, and 6 are shown in FIG.
The positions of the carriages 4 and 6 are at the left end of the movable range D, and the position of the carriage 5 is at the right end of the movable range D.

FIG. 7 is a diagram showing the moving speeds of the carriages 4, 5, and 6. 7 (a) is a velocity V ₁ of the carriage 4, FIG. 7 (b) the speed V ₂ of the carriage 5, 7
6C shows the speed V _{3 of the} carriage 6 with the right direction in FIG. 6 being positive. The carriages 4, 5, and ₆ return to the initial position by making one reciprocation between 0 and t6.

(Period 0 to t ₁ ) Between 0 and t ₁ , the carriages 4, 5, and 6 perform a uniform acceleration motion. The acceleration of the carriage 4 and the carriage 6 is V ₀ / t ₁ [m / s ² ]
(Right direction in the drawing). Acceleration of the carriage 5 -V ₀
/ T ₁ [m / s ² ] (to the left in the drawing). That is,
The directions of the carriages 4 and 6 and the carriage 5 are opposite to each other and have the same magnitude.

During this time, the reaction force F ₁ generated by the uniform acceleration movement of the carriage 4, the reaction force F ₂ of the carriage 5, and the reaction force F ₃ of the carriage 6 are represented by the following equations (1), (2), and (3). It becomes as shown by. However, the right direction in the drawing is positive.

(1) Formula F ₁ = − (V ₀ / t ₁ ) m ₁ (2) Formula F ₂ = − (− V ₀ / t ₁ ) m ₂ = (V ₀ / t ₁ ) m ₂ (3) ) Formula F ₃ = − (V ₀ / t ₁ ) m ₃ As described above, since m ₂ = 2m ₁ = 2 m ₃ , F ₂ + F
₁ + F ₃ = 0, and the total sum of the reaction forces generated by the carriages 4, 5, and 6 moving at a constant acceleration becomes zero.

[0053] Further, the moment M ₁ of the carriage 4 at an arbitrary point P in FIG. 6, the moment M ₂ of the carriage 5, and a moment M ₃ of the carriage 6, the following equation (4), (5), ( 6). However, the clockwise direction in FIG. 6 is positive.

(4) Formula M ₁ = F ₁ (2L + 1) = − (V ₀ / t ₁ ) m ₁ (2L + 1) (5) Formula M ₂ = F ₂ (L + 1) = (V ₀ / t ₁ ) m _{2 (L + l) (6} ) formula _{M 3 = F 3 l = -} (V 0 / t 1) m 3 l as described above, since _{m 2 = 2m 1 = 2m 3} , M 2 + M
₁ + M ₃ = 0, and the moment around any point P becomes zero.

Therefore, between 0 and t ₁ , the reaction force F ₁ ,
Since the sum of F ₂ and F ₃ becomes zero and the moment about an arbitrary point P becomes zero, the recording device does not apply any force in the lateral and rotational directions, and does not theoretically vibrate. However,
In practice, a slight shift occurs in the drive control of the carriages 4, 5, 6 due to variations in the torque performance of the drive units 7, 8, 9 and the like, so that some vibration remains. However, it is an extremely small vibration.

[0056] In between (period t ₁ ~t ₂₎ t ₁ of t _2, the carriage 4, 5, 6 performs a constant velocity motion. Therefore, no reaction force is generated, and during this time, the recording device does not vibrate.

[0057] Between (period t ₂ ~t ₄₎ t ₂ from t _4, the carriage 4, 5, 6 perform uniformly accelerated motion. Acceleration of the carriage 4, 5, and acceleration during the period 0 to t _1, each direction is opposite magnitude the same acceleration. Therefore, as in the case of period 0 to t _1, the reaction force F
_Since the sum of ₁ , F ₂ and F ₃ becomes zero and the moment around any point P becomes zero, no force is applied to the recording apparatus as a whole. Therefore, the recording device does not theoretically vibrate.

[0058] Between (period t ₄ ~t ₅₎ t ₄ from t _5, the carriage 4, 5, 6 performs a constant velocity motion. Therefore, no reaction force is generated, and during this time, the recording device does not vibrate.

[0059] In between (period t ₅ ~t ₆₎ t ₅ of t _6, the carriage 4, 5, 6 perform uniformly accelerated motion. Acceleration of the carriage 4, 5, 6 is the same as the acceleration when the time period 0 to t _1, during this period the recording apparatus, transversely and force in the direction of rotation is not applied, does not vibrate theoretically.

As described above, if the carriages 4 and 6 and the carriage 5 are reciprocated with the same magnitude of acceleration in the opposite directions, the recording apparatus can reduce the influence of the reaction force generated by the movement of the carriages 4, 5 and 6. Without receiving the vibration, the vibration in the lateral direction and the rotational direction can be prevented.

Further, as recording is performed, ink is used and the remaining amount of ink in the ink tank decreases. In the case of color recording, the colors used depend on the information to be recorded.
The amount of remaining ink differs for each color.

The weight ratio of the ink tank (small) 18 or the ink tank (large) 19 to the carriage weights m ₁ , m ₂ and m ₃ is about 10%. Even if the amount of remaining ink varies, the sum of the weight m _{1 of the} carriage 4 and the weight m ₃ of the carriage 6 and the weight m of the carriage 5
The difference from ₂ is a small value with respect to the weight of the carriage.

However, the ink remaining amount varies.
If the difference in carriage weight (m_Two-M ₁-M_ThreeDepending on)
The recording device vibrates because the reaction force affects the recording device.
You. In order to minimize this vibration,
In the embodiment, the ink tank (large
(Type) 19 contains black ink. Carry
The ink (small) 18 held in the di 4, 6 has yellow
-Ink, cyan ink, magenta ink
Is stored. In normal use, the black
Ink usage increases.
Tank in a large tank 19, the weight of the carriage
Difference (m_Two-M₁-M_Three) Can be reduced.
Therefore, the vibration of the recording device can be further reduced.
Wear.

When a light-colored photo ink is used in the recording apparatus, the photo ink is stored in an ink tank (large) 1.
9 is good. This is because the amount of photo ink used in color recording is larger than that of other inks. The remaining ink tank (small) 18 contains normal ink. As a result, in a use state in which color recording is frequently performed, vibration can be reduced as compared with a case where only the black ink is stored in the ink tank (large) 19.

The normal ink includes four colors of yellow ink, magenta ink, cyan ink, and black ink. Photo ink is lighter in color than normal ink,
It consists of four colors, photo yellow, photo magenta, photo cyan, and photo black.

In the case of color recording, since the amount of yellow ink used is relatively large, an ink tank (large) 1 is used.
9 may contain two colors of black ink and yellow ink. The remaining two ink tanks (small) 18
Contains magenta ink and cyan ink. As a result, in a use state in which color recording is frequently performed, vibration can be reduced as compared with a case where only the black ink is stored in the ink tank (large) 19.

[Second Embodiment] FIG. 8 is a perspective view showing a part of a recording apparatus according to a second embodiment. The printing apparatus according to the second embodiment is different from the printing apparatus according to the first embodiment in that the driving units 7, 8, and 9 are combined into one driving unit 7.
It was made. Referring to FIG.
5 and 6 are connected to one timing belt 12. The timing belt 12 is an idle pulley 1
3, the U-shape is stretched in two. The carriages 4, 5, and 6 connected to the timing belt 12
Move according to the movement of 2. The weights m ₁ , m ₂ , and m ₃ of the carriages 4, 5, and 6 are in a relationship of m ₂ = 2m ₁ = 2m ₃ , as in the first embodiment.

As described above, the timing belt 12 is stretched by the idle pulley 13 in such a manner that two U-shapes are arranged.
Can be moved in the same manner as in the first embodiment. That is, the carriage 4 is moved by the drive unit 7 as shown in FIG.
If the carriage 5 is driven at the speed shown in FIG.
At the speed shown in FIG. 7B, the carriage 6 can be driven at the speed shown in FIG. However, one driving unit 7
Drive the carriages 4, 5, and 6 at the same time, so that the driving force of the drive unit 7 is the same as that of the carriage 4 used in the first embodiment.
Requires about four times the torque of the driving force of the driving unit.

If the carriages 4, 5, and 6 are moved at the speed shown in FIG. 7, the carriages 4, 6 and the carriage 5 reciprocate with the same magnitude of acceleration in opposite directions. The speed is not affected by the reaction force generated by the movement of the carriages 4, 5, 6, and vibrations in the lateral direction and the rotation direction can be prevented.

[Third Embodiment] FIG. 9 is a perspective view showing a part of a recording apparatus according to a third embodiment. The printing apparatus according to the third embodiment has a configuration in which four carriages are used and the weights carried by the respective carriages are equal.

Referring to FIG. 9, four carriages 4,
5, 6, 31 are inkjet heads 1,
2, 3, and 30 and an ink tank (small) 18 are mounted. The weights carried by the carriages 4, 5, 6, 31 include the weights of the carriages 4, 5, 6, 31, the weights of the inkjet heads 1, 2, 3, 30, and the ink tank (small).
18 and the total weight. The weights carried by the carriages 4, 5, 6, 31 in the present embodiment are the same.

Hereinafter, the weight carried by the carriage 4 is represented by the weight m _{1 of the} carriage 4, the weight carried by the carriage 5 is represented by the weight m _{2 of the} carriage 5, the weight carried by the carriage 6 is represented by the weight m _{3 of the} carriage 6, and the weight of the carriage 31 is represented by The weight carried is called the weight m _{4 of the} carriage 31.

The carriages 4, 5, 6, 31 are connected to the timing belt 21, respectively. Carriage 4,
5, 6, 31 are driven by the drive units 7, 8, 9, 32, and reciprocate in the main scanning direction by the timing belt 21 and the idle pulley 13. The initial positions of the carriages 4 and 31 are at the left end of the movable range D, and the initial positions of the carriages 5 and 6 are at the right end of the movable range D. The carriages 4, 5, 6, 31 are arranged at equal intervals. In driving the carriage, the carriage 4 and the carriage 31 are driven at the same speed in the same direction, and the carriage 5 and the carriage 6 are driven at the same speed in the opposite direction to the carriage 4 and the carriage 31. .

Now, acceleration of the carriage 4 and the carriage 31
Degree is a [m / s^Two], The carriage 5 and the carriage
The acceleration of di 6 is -a [m / s^Two]. carriage
The reaction force generated by the acceleration of 4, 5, 6, 31 is
Each m₁a, -m_Twoa, m _Threea, -m_Foura.
m₁= M_Two= M_Three= M_FourSo the total reaction force is zero
You. Set the carriage spacing to l₁, Any point P is carried
Around the point P,
Is the moment M of: M = −m_Twoa * l₁-M_Threea * 2l₁+ M_Foura * 3l₁ And m₁= M_Two= M_Three= M_FourSo, M = 0
You.

Therefore, the recording apparatus is composed of the carriage 4,
The vibration in the lateral direction and the rotation direction can be prevented without being affected by the reaction force and moment generated by the movement of 5, 6, 31.

The ink tank (small) 18 held by the carriage 4 holds black ink, the ink tank (small) 18 held by the carriage 5 holds cyan ink, and the ink tank held by the carriage 6 The (small) 18 contains magenta ink, and the ink tank (small) 18 held on the carriage 31 contains yellow ink.

The ink flies as an ink drop from the nozzle 55 and adheres to the recording sheet. It takes a certain time for the adhering ink drop to be absorbed by the recording sheet and dried. If the color is mixed with ink of a different color before the ink dries, the color will not be reproduced clearly. When ink of different colors is caused to fly by an ink jet head held on the same carriage, it is necessary to reduce the main scanning speed of the carriage in order to secure a certain time. On the other hand, if ink of a different color is caused to fly by an inkjet head held by another carriage, the ink can be dried during the sub-scanning of the recording sheet. Does not mix. Therefore, the carriages 4, 5, 6, 31
By changing the color of the ink stored in the ink tank (small size) 18 held in the ink, it is possible to prevent the ink from being mixed before it dries, in addition to the above-described effects, and to enable high-speed printing. Recording quality can be improved.

The ink tank (small) 18 held by the carriage 4 is provided with black ink and photo black ink, the ink tank (small) 18 held by the carriage 5 is provided with cyan ink and photocyan ink, Ink tank (small) 1 held on carriage 6
8 may contain magenta ink and photomagenta ink, and the ink tank (small size) 18 held on the carriage 31 may contain yellow ink and photoyellow ink. In this case, since the same color normal ink and photo ink are caused to fly by the ink jet head held on the same carriage, even if the inks are mixed before the ink dries, the recording quality is not affected. Therefore, also in this case, in addition to the above-described effects, it is possible to prevent color mixture with inks of different colors, to enable high-speed recording, and to improve recording quality.

[Fourth Embodiment] FIG. 10 is a perspective view showing a part of a recording apparatus according to a fourth embodiment.
The recording apparatus according to the fourth embodiment includes an ink tank (small) 18 provided on the carriage 5 according to the first embodiment.
And the weight m _{2 of the} carriage 5 is the same as the weight m _{1 of the} carriage 4 and the weight m _{3 of the} carriage 6. Therefore, m ₁ = m ₂ = m ₃ . The initial position of the carriages 4 and 6 is the left end of the movable range D, and the initial position of the carriage 5 is the right end of the movable range D.

FIG. 11 is a diagram showing the moving speeds of the carriages 4, 5, and 6 in the fourth embodiment. FIG.
(A) is a velocity V ₁ of the carriage 4, FIG. 11 (b) the speed V ₂ of the carriage 5, FIG. 11 (c) the carriage 6
Shows the speed V ₃ of.

(Periods 0 to t ₁ ) From 0 to t ₁ , the carriages 4, 5, and 6 perform a constant acceleration motion. Acceleration of the carriage 4 and the carriage 6, (V _0/2) is / t _1, the acceleration of the carriage 5 is -V ₀ / t _1. That is, the accelerations of the carriages 4 and 6 are opposite in direction to the acceleration of the carriage 5 and are halved in magnitude.

The reaction forces F ₁ , F ₂ ,
F _{3 is, F 1 = (V 0/} 2) / t 1 * m 1 F 2 = -V 0 / t 1 * m 2 F 3 = (V 0/2) / t 1 * m 3 next, m ₁ = M ₂ = m _3, so that F ₂ = F ₁ + F ₃ , and the sum of the reaction forces F ₁ , F ₂ , F ₃ becomes zero. When an arbitrary point P is on the movement line of the carriage 4, the moment M around the arbitrary point P is
6 are arranged at equal intervals l ₁ , M = F ₂ l ₁
+ The 2F ₃ l _1. Since F ₂ = −2F ₃ , M = 0.

Accordingly, during this time, the recording apparatus is not affected by the reaction force and the moment due to the movement of the carriages 4, 5, and 6, so that the lateral and rotational vibrations can be prevented.

(Period t ₁ -t ₂ ) Between t ₁ and t ₂ ,
The carriages 4 and 6 perform a uniform acceleration motion. The carriage 5 moves at a constant speed.

The reaction forces F ₁ and F ₃ generated by the movement of the carriages 4 and 6 are the same as in the period 0 to t ₁ . The carriage 5 does not generate a reaction force.

Therefore, the sum of the reaction forces is V ₀ / t ₁ *
m ₁ , and the recording apparatus vibrates by receiving a reaction force in the direction opposite to the direction in which the carriages 4 and 6 move.

[0087] Further, as an arbitrary point P is the moment around the arbitrary point P when the to be in the moving line of the carriage 4, the carriage 4, 5, 6 are arranged at regular intervals l _1, M = V ₀ / t ₁ * m ₃ . Therefore,
The recording device vibrates by receiving a rotating force. However, during this period, only a constant force is applied in one direction for a short period of time, and there is no change in the direction of the applied force. If the direction of the force applied at both ends of reciprocating abruptly changes (when in Fig. 5, t _5), the recording apparatus is vibrated violently lateral and direction of rotation, applied force in only one direction In this case, the vibration of the recording device becomes relatively small.

(Period t ₂ -t ₃ ) From t ₂ to t ₃ , no force is applied to the recording apparatus because the carriages 4, 5, and 6 move at a constant speed. Therefore, the recording device does not vibrate.

(Period t ₃ to t ₄ ) From t ₃ to t ₄ , the carriages 4 and 6 have the same magnitude of acceleration in the opposite direction as in the period t _{1 to} t ₂ . The carriage 5 moves at a constant speed.

Accordingly, since a constant force is applied to the recording device in one direction, the recording device vibrates in the lateral direction and the rotating direction, but the vibration is relatively small.

[0091] In t ₅ from (time t ₄ ~t ₅₎ t _4, the carriage 4, 5 and 6 to the uniformly accelerated motion. Acceleration of the carriage 4, 5, 6 is the same size in the acceleration in the opposite direction of the period 0 to t _1.

Therefore, during this time, the recording apparatus is not affected by the reaction force and the moment due to the movement of the carriages 4, 5, and 6, and can prevent the vibration in the lateral and rotational directions.

[0093] is the same as in the case of (period t ₅ ~t ₆₎ period t ₄ ~t _5.

(Period t ₆ -t ₇ ) Same as period t ₃ -t ₄ .

(Periods t _{7 to} t ₈ ) The other points are the same as those in the periods t _{2 to} t ₃ except that the traveling speeds of the carriages 4, 5, and 6 are reversed.

(Period t ₈ -t ₉ ) Same as period t ₁ -t ₂ .

(Periods t _{9 to} t ₁₀ ) The same as in the case of periods 0 to t ₁ .

[0098] Thus, by controlling the carriage 4, 5, 6 by the drive unit 7, 8 and 9, a short period in the recording apparatus (the period t ₁ ~t _2, the period t ₃ ~t _4, the period t ₅ ~ t ₇ , period t
₈ ~t ₉₎ a force that generates vibration is applied while the vibration therebetween can be suppressed to relatively small vibration.

[Fifth Embodiment] FIG. 12 is a perspective view showing a part of a recording apparatus according to a fifth embodiment.
Referring to the drawing, the carriage 4 has mounted thereon inkjet heads 1 and 3 and two ink tanks 42 for supplying ink to the inkjet heads 1 and 3, respectively. The carriage 41 has the inkjet head 2 and an ink tank 43 for supplying ink to the inkjet head 2 mounted thereon.

The carriage 40 and the carriage 41 are supported by the sliding shafts 10 and 11 so that they can move in parallel. The carriages 40 and 41 are coupled to a timing belt (not shown), and are independently driven by a driving unit (not shown).
Driven along 0,11. Other configurations are the same as those of the recording apparatus according to the first embodiment, and thus description thereof will not be repeated. The carriage 40 is shaped so as to wrap the carriage 41 such that its center of gravity overlaps the center of gravity of the carriage 41. Therefore, the carriage 40
When the and the carriage 41 move, the respective centers of gravity move on the same straight line. The weight carried by the carriage 40 and the weight carried by the carriage 41 are the same. Further, the carriage 40 and the carriage 41 are controlled so as to reciprocate along the sliding shafts 10 and 11 at the same speed in opposite directions.

As a result, the reaction force generated when the carriage 40 and the carriage 41 perform acceleration / deceleration have the same magnitude but opposite directions. That is, the sum of the reaction forces is zero.

Since the center of gravity is on the same straight line and the reaction force acts on that straight line, no moment is generated.

Therefore, the recording apparatus according to the present embodiment is not affected by the reaction force generated by the movement of the carriages 40 and 41, and can prevent the lateral and rotational vibrations.

[Sixth Embodiment] The ink in the ink tank decreases as recording is performed. In the case where a plurality of inkjet heads are used, if the amount of ink used differs depending on the inkjet head, the amount of ink remaining in the ink tank will differ. The ratio of the ink weight when the ink in the ink tank is full to the weight carried by the carriage is:
It is about 10%.

However, since the difference in the remaining amount of ink is the difference in the weight carried by the carriage, this difference becomes the difference in the magnitude of the reaction force, and vibrates the recording apparatus. However, the ratio of the difference in the remaining amount of ink in the ink tank to the weight carried by the carriage is smaller than 10%. Since the difference in the magnitude of the reaction force due to the difference in the remaining amount of ink is small, the vibration of the recording apparatus is also small.

The recording apparatus for eliminating the minute vibration is the sixth apparatus.
The embodiment will be described. FIG. 13 is a perspective view showing a part of the recording apparatus according to the sixth embodiment. Referring to the figure, carriages 4, 5, and 6 have inkjet heads 1, 2, and 3 mounted thereon. The carriages 4, 5, 6
It is supported so that it can move along the sliding shafts 10 and 11. The carriages 4, 5, 6 are connected to a timing belt 12, and are driven along sliding shafts 10, 11 by driving units 7, 8, 9.

The ink tank 45 is attached to the main body of the recording apparatus, and the ink in the ink tank 45 is supplied to the ink jet heads 1, 2, and 3 via the tube 46.
Other configurations are the same as those of the recording apparatus according to the first embodiment, and thus description thereof will not be repeated.

In the recording apparatus having such a configuration, since the difference in the remaining amount of ink does not become the difference in the magnitude of the reaction force, it is further possible to prevent the recording apparatus from vibrating minutely.

Further, since the weight carried by the carriage is reduced by the weight of the ink and the weight of the ink tank, it is possible to reduce the manufacturing cost and the power consumption by reducing the torque of the drive units 7, 8, and 9 of the carriage. Can be planned.

Further, since the ink tank is mounted on the main body of the recording apparatus, a large-capacity ink tank can be mounted without having to reduce the size and weight of the ink tank. This makes it possible to provide a recording apparatus that does not require ink replacement for a long time.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a recording apparatus according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a schematic configuration of a control unit of the printing apparatus according to the first embodiment of the present invention.

FIG. 3 is a plan view showing a part of a surface of the inkjet head having nozzles.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a sectional view taken along line BB of FIG. 4;

FIG. 6 is a schematic diagram illustrating a positional relationship of a carriage according to the first embodiment.

FIG. 7 is a diagram illustrating a moving speed of a carriage according to the first embodiment.

FIG. 8 is a perspective view illustrating a part of a recording apparatus according to a second embodiment.

FIG. 9 is a perspective view illustrating a part of a recording apparatus according to a third embodiment.

FIG. 10 is a perspective view illustrating a part of a recording apparatus according to a fourth embodiment.

FIG. 11 is a diagram illustrating a moving speed of a carriage according to a fourth embodiment.

FIG. 12 is a perspective view illustrating a part of a recording apparatus according to a fifth embodiment.

FIG. 13 is a perspective view illustrating a part of a recording apparatus according to a sixth embodiment.

FIG. 14 is a perspective view illustrating a schematic configuration of a conventional recording apparatus.

[Explanation of symbols]

 1,2,3 Inkjet head 4,5,6 Carriage 7,8,9 Drive unit 18 Ink tank (small) 19 Ink tank (large)

Claims (7)

[Claims] 1. At least three reciprocating motions parallel to each other
And at least one of the at least three carriages has an ink-jet head, and the drive unit is configured to drive the at least three carriages by driving the at least three carriages. Driving the at least three carriages to minimize the sum of forces, wherein the carriages are arranged such that a moment about any one point is minimized during driving of the at least three carriages. A recording device, characterized in that: 2. The method according to claim 1, wherein the driving unit is one, and the at least three carriages are coupled to a transmission unit, and the driving unit drives the at least three carriages by driving the transmission unit. The recording apparatus according to claim 1, wherein: 3. The recording apparatus according to claim 1, wherein a black ink or a photo ink is mounted on one of the at least three carriages that has a large weight. 4. The recording apparatus according to claim 1, wherein a black ink and a yellow ink are mounted on a carriage having a large weight among the at least three carriages. 5. The recording apparatus according to claim 1, wherein the at least three carriages carry ink of the same color. 6. The apparatus according to claim 1, wherein the at least three carriages carry inks of different colors.
Or the recording device according to 2. 7. At least two reciprocating motions parallel to each other
Two carriages, and a drive unit for driving the at least two carriages, respectively, at least one of the at least two carriages,
Having an inkjet head, wherein the center of gravity of each of the at least two carriages is
One parallel to the moving direction of the at least two carriages;
The printing apparatus according to claim 1, wherein the driving unit drives the at least two carriages so as to minimize a total reaction force generated by driving the at least two carriages.