JP2009297903A - Liquid jet apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid jet apparatus which can lessen striking shift of a liquid when expansion and contraction of a head holding member because of a change in temperature. <P>SOLUTION: Each recording head 3 is attached to a head holder 25 via a first supporting member 30a of a first coefficient of linear expansion α and a second supporting member 30b of a second coefficient of linear expansion β larger than the first coefficient of linear expansion α. Regarding an arrangement of the first supporting member and the second supporting member, the first supporting member is arranged on the farther side than the second supporting member to a first fixing part in a first direction X. The material of each supporting member is selected so that the second coefficient of linear expansion β of the second supporting member may be larger than the first coefficient of linear expansion α of the first supporting member. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a liquid ejecting apparatus including a liquid ejecting head such as an ink jet recording head, and more particularly to a liquid ejecting apparatus in which a plurality of liquid ejecting heads are arranged at regular intervals in a relative feed direction with respect to an ejected object.

  For example, a liquid ejecting apparatus is an apparatus that includes a liquid ejecting head capable of ejecting liquid and ejects various liquids from the liquid ejecting head. As a typical example of this liquid ejecting apparatus, for example, an ink jet recording head (hereinafter simply referred to as a recording head) as a liquid ejecting head is provided, and liquid ink is recorded on recording paper or the like from a nozzle opening of the recording head. An image recording apparatus such as an ink jet printer that records an image or the like by ejecting and landing on a medium (a target to be ejected) to form dots can be given. In recent years, liquid ejecting apparatuses have been applied not only to this image recording apparatus but also to various manufacturing apparatuses such as a manufacturing apparatus for color filters such as liquid crystal displays.

  An ink jet recording apparatus (printer), which is a kind of liquid ejecting apparatus, includes an ink jet recording head (a type of liquid ejecting head, so-called serial head) that is shorter than the width of a recording medium, and reciprocates in the main scanning direction. A head moving mechanism for moving the recording medium, a recording medium (ejecting object) such as recording paper, a transport mechanism for feeding the recording medium in a direction orthogonal to the main scanning direction, and performing sub-scanning. It is configured to record an image or the like on the recording medium by sequentially repeating the conveyance (sub-scanning) of the recording medium. However, in this method, since the scanning speed of the recording head is limited, for example, when an image is recorded on the entire surface of a relatively large size recording medium such as A2, there is a problem that much time is required. was there.

  Therefore, in recent years, a plurality of unit heads are arranged in a second direction orthogonal to the first direction (relative feed direction) in which the recording head and the recording medium move (send) relatively, and are formed by the unit head group. There has been proposed a printer configured such that the total length of the nozzle group to be handled corresponds to the maximum recording width of the recording medium. According to this configuration, it is not necessary to scan the recording head in the second direction, and an image or the like can be recorded by a relative feeding operation in the first direction between the recording head and the recording medium. The recording time can be shortened compared to

  Also proposed is a printer having a configuration in which a plurality of the recording heads are arranged at regular intervals in the first direction in a posture in which the head longitudinal direction is aligned with the second direction on a frame-like head holder formed of, for example, metal. (For example, refer to Patent Document 1). According to this configuration, the recording time can be further shortened or a plurality of colors can be printed.

  By the way, in a printer having such a configuration, when the head holder expands or contracts due to a change in environmental temperature or the heat generated by the recording head itself, the interval between the recording heads fixed to the head holder fluctuates, and the ink is transferred onto the recording medium. As a result, the recording quality of an image or the like may be deteriorated.

JP 2006-321122 A

  For this reason, in the printer disclosed in Patent Document 1, both ends in the longitudinal direction of the recording head (head bar) are supported by the fine movement guide means so as to be freely finely movable with respect to the head holder. By connecting each other in the paper transport direction with a connecting member made of a material having a small linear expansion coefficient, the head holder is adapted to cope with thermal expansion.

  However, even in the above configuration, it is difficult to completely prevent landing position deviation due to expansion and contraction due to temperature changes of the head holder and the head itself, and each recording head is supported so that it can be finely moved freely with respect to the head holder. Further, there is a possibility that the position of the recording head with respect to the head holder is shifted due to vibration or the like. Moreover, although glass (hard glass) or ceramic is applied to the member that connects the head bars, since both are hard and brittle materials, there is a problem that processing is difficult. Furthermore, in the case of a configuration in which a plurality of nozzle rows are arranged on one head bar in the paper transport direction, landing errors may occur due to expansion and contraction of the head bar itself in the paper transport direction. No consideration is given.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid ejecting apparatus capable of reducing the landing deviation of the liquid when the head holding member expands and contracts due to a temperature change. is there.

A liquid ejecting apparatus of the present invention has been proposed to achieve the above object, and a liquid ejecting head capable of ejecting liquid from a plurality of nozzle openings toward a liquid ejecting target;
A head holding member for holding the liquid jet head;
A liquid ejecting apparatus comprising:
The head holding member is fixed to the apparatus main body side with first fixing portions on both sides in a direction orthogonal to a relative feed direction between the jetting object and the liquid jet head during a liquid jetting operation,
The liquid ejecting head includes the first support member having a first linear expansion coefficient α and the second support member having a second linear expansion coefficient β larger than the first linear expansion coefficient α. Attached to the head holding member,
The first support member is disposed on a side farther than the second support member with respect to the first fixed portion in the relative feeding direction.

  According to the above configuration, the liquid ejecting head is attached to the head holding member via the first support member and the second support member having a larger linear expansion coefficient than the first support member, and the first support member is moved in the relative feed direction. When the head holding member expands and contracts in the relative feed direction with the first fixed portion as a base point by arranging the first fixed portion on the side farther than the second support member, the first support member and Due to the difference in displacement in the height direction of the second support member (the dimension in the direction perpendicular to the upper surface of the head holding member), the liquid ejecting head is arranged on the head holding member so that the nozzle forming surface faces the first fixed portion side. Lean against. As a result, the liquid ejected from the nozzle opening of the liquid ejecting head flies obliquely with respect to the ejected object, and the landing position on the landing surface can be brought close to the original desired landing position before the temperature change. And after the change, the deviation of the landing position of the liquid on the injection target is reduced.

  In the above configuration, the liquid ejecting head disposed at a position farther in the relative feed direction than the first fixed portion narrows the interval between the first support member and the second support member, while the first It is desirable to employ a configuration in which the liquid ejecting head disposed closer to the fixed portion in the relative feed direction increases the distance between the first support member and the second support member.

  According to the above configuration, the tilt amount of the liquid ejecting head can be changed according to the arrangement position of the liquid ejecting head with respect to the head holding member without changing the combination of the materials of the support member for each liquid ejecting head. For this reason, management of the material of a support member becomes easy and it can also suppress cost.

  Further, the liquid ejecting head disposed at a position farther from the first fixed portion in the relative feed direction increases the difference between the first linear expansion coefficient α and the second linear expansion coefficient β. The difference between the first linear expansion coefficient α and the second linear expansion coefficient β is reduced as the liquid ejecting head is disposed closer to the first fixed portion in the relative feed direction. Further, it is possible to adopt a configuration in which the materials of the first support member and the second support member are made different according to the arrangement position of the liquid ejecting head with respect to the first fixed portion.

  This configuration is suitable when the interval between the first support member and the second support member cannot be changed for each liquid ejecting head.

  In each of the above configurations, the configuration in which the first fixing portion is provided at a position corresponding to the middle of the plurality of liquid ejecting heads arranged on the head holding member at regular intervals in the relative feed direction is adopted. You can also.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In the embodiments described below, various limitations are made as preferred specific examples of the present invention. However, the scope of the present invention is not limited to the following description unless otherwise specified. However, the present invention is not limited to these embodiments. In the present embodiment, an image recording apparatus that is one form of the liquid ejecting apparatus, and more specifically, a length corresponding to the maximum recording width of a recording sheet that becomes an ejection target (or recording medium) at equal intervals between nozzle openings. An ink jet printer (hereinafter referred to as a printer) equipped with a long liquid ejecting head (hereinafter simply referred to as a recording head) arranged in FIG.

  FIG. 1 is a cross-sectional view illustrating a schematic configuration of a printer 1 according to the present invention, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2, and FIG. 4 is a diagram for explaining a mounting state of the recording head 3 (3a to 3d) with respect to the head holder 25. The printer 1 of the present embodiment includes a plurality of recording papers 4 in the direction (hereinafter referred to as the second direction Y) orthogonal to the direction of conveyance of the recording paper 4 by the conveyance unit 7 (corresponding to the relative feed direction in the present invention; Paper feed tray 5a and apparatus for storing recording heads 3 (a kind of liquid ejecting head of the present invention) configured by arranging unit heads 11 and recording paper 4 (a kind of ejecting object of the present invention) in a stacked state. A sheet feeding unit 5 including a lower sheet feeding cassette 5b provided at a lower portion and a recording sheet 4 fed from these sheet feeding units 5a and 5b are passed under the recording head 3 (3a to 3d) and discharged. A transport unit 7 transported to the paper tray 10 side and a paper discharge tray 10 for holding the recording paper 4 on which recording is performed by the recording head 3 and discharged from the transport unit 7 side are provided, and the recording head 3 is moved in the second direction. Without scanning to Y It is configured to be able to record text or images, etc. to the full width of the recording area of Rokushi 4.

  In addition, a printer controller 9 responsible for electrical control of each unit is provided inside the housing 2. The printer controller 9 has a drive signal generation circuit (not shown), and outputs a drive signal from the drive signal generation circuit to the unit head 11 of the recording head 3 through a signal cable. Further, although not shown, an ink cartridge (a type of liquid supply source) that stores ink is disposed inside the housing 2. The ink stored in the cartridge is supplied (pressure-fed) to each unit head 11 of the recording head 3 through the ink supply tube by pressurizing the ink cartridge by an air pump or the like. It is also possible to employ a configuration in which recording is performed while the recording head 3 is scanned in the second direction Y with respect to the recording paper 4.

  The paper feed tray 5a is configured to be movable in the vertical direction. The upper surface of the recording paper bundle (the upper surface of the uppermost recording paper 4) is always in contact with the pickup roller 6 with a constant pressure. The vertical position is controlled. Then, according to the execution timing of the recording operation by the recording head 3, the recording paper 4 is sequentially pulled out from the top of the recording paper bundle by the pickup roller 6, and separated one by one by the separation roller 12 and the separation pad 13. It is fed to the downstream side. After passing between paper sensors (not shown), the recording paper 4 abuts against the nip portion of the pair of upper and lower registration rollers 14a and 14b. The recording paper 4 from the lower paper feed cassette 5b reaches the nip portion of the registration rollers 14a and 14b after passing through a plurality of intermediate rollers 15. Thereby, the leading edge posture of the recording paper 4 is aligned, and the skew of the recording paper 4 is corrected. Thereafter, the registration rollers 14a and 14b feed the recording paper 4 one by one to the conveying unit 7 side by side with a predetermined timing, and the recording paper 4 reaches the conveying belt 17 of the conveying unit 7. The nip state is released at a predetermined timing.

  The transport unit 7 is stretched between a driving roller 18 rotated by a driving force of a driving motor (not shown), a driven roller 19 disposed upstream of the driving roller 18, and the driving roller 18 and the driven roller 19. The endless conveyor belt 17 is configured by a tension roller 20 that applies tension to the conveyor belt 17 and a presser roller 21. The tension roller 20 is disposed between the driving roller 18 and the driven roller 19, abuts against the conveyor belt 17 from the inside, and applies tension to the conveyor belt 17 by an urging force of an urging member such as a spring. . The pressing roller 21 is disposed directly above the driven roller 19 with the conveyance belt 17 interposed therebetween, and presses the recording paper 4 on the conveyance belt toward the conveyance belt 17 so that the adhesion of the recording paper 4 to the conveyance belt 17 is achieved. Increase.

  The driving roller 18 is configured to rotate the conveying belt 17 by being driven in synchronization with the recording operation of the recording head 3 and to convey the recording paper 4 to the downstream side through the lower side of the recording head 3. ing. Further, the rotation amount of the conveyor belt 17 is detected by a rotary encoder (not shown) disposed at the shaft end portion extended from the driven roller 19. The encoder detection signal is output to the printer controller 9 as an encoder pulse.

  Here, when recording is performed on only one surface of the recording paper 4, the recording is performed from the transport unit 7 to the paper discharge tray 10 after the recording on one surface is completed. On the other hand, when recording is performed on both sides of the recording paper 4, after recording on one side is completed, the recording paper 4 is transported to the paper reversing path R <b> 2 by the flapper 22 disposed downstream of the transport unit 7. After the recording paper 4 reaches the U-turn portion T of the paper reversing path, the conveyance direction is changed, and the recording paper 4 is sequentially sent again to the registration rollers 14a and 14b and the conveyance belt 17 to complete the recording on the other side. After that, the paper is discharged from the transport unit 7 to the paper discharge tray 10.

  As a configuration for improving the adhesion of the recording paper 4 to the conveyance belt 17, a method in which the surface of the conveyance belt is charged by a charging roller (not shown) and the recording paper 4 is adsorbed on the conveyance belt by electrostatic force (electrostatic adsorption method). Alternatively, a known technique such as a method (suction method) in which the recording paper 4 is adsorbed on the conveyance belt by generating a negative pressure between the recording paper 4 and the conveyance belt 17 with a fan (not shown) or the like may be adopted. it can. In addition, a maintenance unit (wiping mechanism, capping mechanism, etc.) is provided inside the housing 2 in order to prevent clogging of the nozzle openings of the recording head 3, etc., all of which have various known configurations. Since it can be employed, its description is omitted.

  As shown in FIG. 2, the recording head 3 is configured by arranging a plurality of unit heads 11 in a second direction Y in a unit holder 24. A plurality of recording heads 3, in this embodiment, four recording heads 3 a to 3 d, have a constant arrangement interval in the first direction X with the head longitudinal direction (unit holder longitudinal direction) aligned in the second direction Y. (For example, 100 mm) is attached to the head holder 25 (corresponding to the head holding member in the present invention). Each of the recording heads 3a to 3d includes a pressure chamber communicating with the nozzle opening and pressure generating means (for example, a piezoelectric vibrator, a heating element, etc.) that causes a pressure variation in the ink in the pressure chamber (both shown in the figure). (Not shown), by applying a drive signal from the printer controller 9 to the pressure generating means to drive the pressure generating means, ink (a kind of liquid in the present invention) is ejected from the nozzle openings and landed on the recording paper 4 The recording operation (liquid ejecting operation) is performed.

  A plurality of nozzle openings for ejecting ink are provided in the second direction Y on the nozzle forming surface 26 of each unit head 11 to form a nozzle row 27 (a type of nozzle group, see FIG. 4). Are formed in the first direction X. One nozzle row 27 is composed of, for example, 360 nozzle openings opened at a pitch of 360 dpi. In each unit head 11, one nozzle row 27 corresponds to each ink type, that is, each ink color. In the present embodiment, each unit head 11 has a total of four rows corresponding to four colors of ink, cyan ink (C), magenta ink (M), yellow ink (Y), and black ink (K). Nozzle rows 27a to 27d (see FIG. 6) are formed side by side in the first direction X.

  In the present embodiment, the first recording head 3a and the second recording head 3b are paired, and the third recording head 3c and the fourth recording head 3d are paired. The two recording heads 3 forming a pair have an arrangement layout in which the unit heads 11 are alternately arranged in a two-stage zigzag pattern at an arrangement interval such that the nozzle openings are arranged at 360 dpi as a whole when viewed in the second direction Y. Yes. Note that the number of unit heads 11 in one recording head 3 is determined according to the maximum size of the recording paper 4 that the printer 1 can handle.

  As shown in FIG. 5, the head holder 25 is a rectangular frame-shaped member composed of four beams 25a to 25d. The frame of the head holder 25 is an empty portion 29, and each unit head 11 of the recording head 3 is arranged in the empty portion 29. Further, the head holder 25 is fixed to both sides of the printer main body, that is, the frame member 34 provided on the housing 2 side in a doubly supported beam shape on both sides (first beam 25a, second beam 25b) in the second direction Y. The attachment member 31 is attached.

  The first beam 25a and the second beam 25b are each provided with a female screw portion 35 having a circular cross section, and an insertion hole (not shown) of the frame member 34 formed corresponding to the female screw portion 35. The head holder 25 is fixed to the frame member 34 by screwing the fastening member 31 such as a screw into the female screw portion 35 through the screw. Hereinafter, this fixing portion is referred to as a first fixing portion. In the present embodiment, the position of the first fixing portion is a position corresponding to the fourth nozzle row 27d of the second recording head 3b in the first direction X. That is, in plan view, the fourth nozzle row 27d of the second recording head 3b and the first fixing portions on both sides are aligned on a straight line.

  In addition, at both ends in the longitudinal direction (first direction X) of the first beam 25a and the second beam 25b, the inner dimension in the second direction Y is aligned with the inner diameter of the female screw portion 35 (specifically, slightly On the other hand, long holes 36 each having an inner dimension in the first direction X that is designed to be sufficiently larger than the inner diameter of the female screw portion 35 are respectively opened. 31 is fitted without being fixed. That is, a gap having a size corresponding to the difference between the inner dimension in the first direction X of the long hole 36 and the inner diameter of the insertion portion of the fixing member 31 is formed between the long hole 36 and the fixing member 31. . Therefore, within the gap, the head holder 25 is allowed to expand and contract in both directions in the first direction X with the first fixed portion as a base point (reference B in FIG. 4), and the head holder 25 and the frame member 34 The mechanical stress during is reduced.

As shown in FIG. 3, the unit holder 24 includes a base plate 24a that is long in the second direction Y, side wall portions 24b that stand upward from both longitudinal edges of the base plate 24a, and each side wall portion 24b. And a flange portion 24c extending laterally (on the opposite side to the base plate 24a side). Each recording head 3 has a first support arranged in the first direction X between the flange portions 24c on both sides of the unit holder and the head holder 25 (first beam 25a and second beam 25b). The member 30a and the second support member 30b are attached to the head holder 25 in a state where they are interposed. However, the second recording head 3b is supported by the head holder 25 only by the first support member 30a without using the second support member 30b because there is little deviation in the ink landing position due to thermal expansion of the head holder 25. Yes.
The total length W1 in the longitudinal direction of the base plate 24a is designed to be slightly smaller than the inner dimension W2 in the second direction Y of the empty portion 29 of the head holder 25, and the base plate 24a is disposed in the empty portion 29. It is like that.

  As shown in FIG. 6A, the support members 30a and 30b and the head holder 25 are fixed by a fixing member 32, and the unit holder 24 and the support members 30a and 30b of the recording heads 3a to 3d are fixed. Each of the fixing members 33 is fixed. In the present embodiment, when viewed in the first direction X, the arrangement position of the first support member 30 a is matched with the position of the fourth nozzle row 27 d of the recording head 3. Further, regarding the arrangement of the first support member 30a and the second support member 30b, the first support member 30a is arranged on a side farther than the second support member 30b with respect to the first fixed portion in the first direction X. . The external dimensions such as the height under the reference temperature (for example, 25 ° C.) of the first support member 30a and the second support member 30b are aligned. The materials of the support members 30a and 30b are selected so that the second linear expansion coefficient β of the second support member 30b is larger than the first linear expansion coefficient α of the first support member 30a. .

  With this configuration, the support member 30a that supports the recording head 3 when the head holder 25 expands and contracts in the first direction X with the first fixing portion as a base point due to a change in environmental temperature or heat generation of the recording head itself. , 30b similarly expands and contracts as a whole, but the expansion / contraction amount (displacement amount) at the time of temperature change also differs between the first support member 30a and the second support member 30b due to the difference in linear expansion coefficient. That is, the displacement amount of the second support member 30b closer to the first fixed portion is larger than the displacement amount of the first support member 30a disposed on the far side with respect to the first fixed portion. Due to the difference in displacement, the recording head 3 supported by these support members 30 a and 30 b is inclined with respect to the head holder 25 as shown in FIG. 6B. In the figure, for easy understanding, it is shown to expand and contract more greatly than actual. Due to the inclination of the recording head 3, even when the head holder 25 expands and contracts, the ink landing position on the recording paper 4 is prevented from changing. Hereinafter, this point will be described with reference to the schematic diagram shown in FIG.

FIG. 7A is a schematic diagram for explaining an inclined state of the recording head 3 due to expansion (thermal expansion) of the support members 30a and 30b when the temperature rises. FIG. 7B is a dimension of each part at that time. FIG. In this figure, the case of the third recording head 3c is illustrated.
Here, the distances in the first direction X from the first recording head 3a, the third recording head 3c, and the fourth recording head 4d to the first fixed portion as the reference B are Pa, Pc, and Pd, respectively. In the present embodiment, since the arrangement pitch P of the recording heads 3 in the first direction X is constant, Pa = Pc = P and Pd = 2P (see FIG. 4).

  For example, when the temperature around the head rises by ΔT from a specified temperature (for example, 25 ° C.) and the head holder 25 extends in the first direction X, the first support member 30a has an upper surface of the head holder 25 by ΔS1. The second support member 30b is displaced in a direction perpendicular to the upper surface of the ΔS2 head holder 25. Due to the difference in displacement between the first support member 30a and the second support member 30b, the recording head 3 is centered on the virtual rotation axis Va parallel to the second direction Y, as shown in FIG. The nozzle forming surface 26 is rotated and tilted in the direction in which the nozzle forming surface 26 faces the first fixed portion. Note that the position of each nozzle row 27 is slightly displaced in the first direction X before and after the inclination due to the inclination of the recording head 3, but the amount of displacement is so small that it can be ignored in calculation.

Here, when the height of the first support member 30a and the second support member 30b at the specified temperature (the dimension in the direction perpendicular to the upper surface of the head holder 25) is S, the first support member 30a in the above case The displacement amounts ΔS1, ΔS2 of the second support member 30b are indicated as follows, respectively.
ΔS1 = S × α × ΔT (A)
ΔS2 = S × β × ΔT (B)

7B, when the distance between the first support member 30a and the second support member 30b in the first direction X is L, and the distance from the second support member 30b to the virtual rotation axis Va is L0. The following formula (C) is established by the similarity law of triangles.
L0: ΔS2 = (L0−L): ΔS1 (C)
As a result, the following equation (D) is derived.
L0 = L × ΔS2 / (ΔS2−ΔS1) (D)
Substituting the formulas (A) and (B) into the above formula (D), the following formula (E) is obtained.
L0 = L × β / (β−α) (E)

Furthermore, the distance from the upper surface of the head holder 25 to the nozzle forming surface 26 is D, the distance from the nozzle forming surface 26 to the recording surface of the recording paper 4 is PG, and the ink landing position on the recording surface due to the inclination of the recording head 3 Assuming that the amount of misalignment (correction amount) in the first direction X is ΔX, the following equation is obtained according to the triangle similarity rule in FIG.
L0: ΔS2 = (S + D + PG): ΔX (F)
ΔX = ΔS2 × (S + D + PG) / L0 (G)
Substituting the formulas (B) and (E) into the above formula (G), the following formula (H) is obtained.
ΔX = S × ΔT × (β−α) × (S + D + PG) / L (H)

Further, the linear expansion coefficient in the first direction X of the head holder 25 is γ (1 / ° C.), from the first fixed portion as the reference B to each recording head 3 (in the present embodiment, up to the fourth nozzle row 27d). When the distance in the first direction is P (mm), the displacement amount Δh of the fourth nozzle row 27d of the third recording head 3c due to the thermal expansion of the head holder 25 is expressed by the following formula (I).
Δh = P × γ × ΔT (I)

In order to cancel the ink landing position deviation in the first direction X on the recording surface of the recording paper 4 by tilting the recording head 3 to make the ink flying direction oblique to the recording paper 4 as described above. The following equation (J) may be established.
ΔX = Δh (J)
Substituting the formulas (H) and (I) into this formula yields the following formula (K).
L = (β−α) / γ × S × (S + D + PG) / P (K)

Similarly, when the temperature around the head is decreased by ΔT, the displacement direction of the head holder 25 and each of the support members 30a and 30b is opposite to that described above. In this case, the above formula (K) is also established.
In other words, the ink landing position deviation in the first direction X is suppressed by determining the material of the head holder 25, the material of the support members 30a and 30b, the dimensions, and the arrangement interval so as to satisfy the above formula (K). Can do.

  Table 1 below shows examples of combinations of materials of the support members 30a and 30b and the head holder 25 selected based on the above (K), and typical dimensions of each part. In Table 1, the upper two rows indicate the cases of the first recording head 3a and the third recording head 3c (P = 100 (mm)) in the above embodiment, and the lower two rows indicate the fourth recording head 3d. The case (P = 200 (mm)) is shown.

  From the combinations shown in Table 1, the head holder 25 is made of an iron alloy, the first support member 30a is made of an invar material (63.5 wt% Fe-36.5 wt% Ni alloy or the like), and the second support member 30b is made of an aluminum alloy. When each material is used, it is possible to take practically realistic dimensions. In the present embodiment, the displacement of the landing position of the ink on the recording surface of the recording paper 4 increases as the recording head 3 (3d) disposed farther in the first direction X than the first fixed portion. The inclination L of the recording head 3 is increased by narrowing the distance L between the first support member 30a and the second support member 30b, thereby increasing the correction amount (ΔX). On the other hand, since the recording head 3 (3a, 3c) arranged closer to the first fixed portion in the first direction X has a smaller ink landing position deviation on the recording surface, the first support The correction amount is reduced by increasing the distance L between the member 30a and the second support member 30b. With such a configuration, the tilt amount (correction amount) of the recording head 3 can be changed only by changing the distance L between the supporting members 30a and 30b without changing the combination of the materials of the supporting members 30a and 30b for each recording head. it can. For this reason, management of the material of the support members 30a and 30b becomes easy, and the cost can be suppressed. In addition, since the head holder 25 and the support members 30a and 30b are formed of a metal material, the processing is easy as compared with the case where a brittle material such as glass or ceramic is used.

  Note that the configuration is not limited to the configuration in which the interval between the first support member 30a and the second support member 30b is changed according to the arrangement position of the recording head 3 in the first direction X with respect to the first fixed portion. Accordingly, the combination of the materials of the first support member 30a and the second support member 30b may be changed. That is, the difference between the first linear expansion coefficient α and the second linear expansion coefficient β is increased as the recording head 3 (3d) is located farther in the first direction X than the first fixed portion. On the other hand, the difference between the first linear expansion coefficient α and the second linear expansion coefficient β is smaller in the recording heads 3 (3a, 3c) arranged closer to the first fixed portion in the first direction X. As such, a combination of materials of the first support member 30a and the second support member 30b may be selected. This configuration is suitable when the distance between the first support member 30a and the second support member 30b cannot be changed due to the structure of the recording head 3 or the like.

As described above, the recording head 3 is attached to the head holder 25 with the first support member 30a and the second support member 30b having a larger linear expansion coefficient therebetween, and the first support member 30a is attached in the first direction. When X is arranged on the side farther than the second support member 30b with respect to the first fixed portion, a temperature change ΔT occurs and the head holder 25 expands and contracts in the first direction X with the first fixed portion as a base point. Each recording head 3 rotates about the virtual rotation axis Va and tilts with respect to the head holder 25 due to the difference in the amount of displacement in the height direction of the support members 30a and 30b. Thereby, the ink ejected from the nozzle openings of the recording heads 3 also flies obliquely with respect to the recording surface of the recording paper 4, and the landing position on the recording surface can be brought close to the original landing position before the temperature change. That is, even when the head holder 25 expands and contracts due to a temperature change, the ink landing position deviation in the first direction X on the recording surface of the recording paper 4 is reduced before and after the temperature change. As a result, it is possible to suppress deterioration in image quality of recorded images and the like.
The support members 30a and 30b and the head holder 25 are fixed by a fixing member 32, and the unit holder 24 and the support members 30a and 30b of the recording heads 3a to 3d are fixed by a fixing member 33, respectively. Therefore, rattling is unlikely to occur between the members, thereby ensuring the positioning of the recording head 3 with respect to the head holder 25 with high accuracy.

  Note that the recording head 3 itself also undergoes expansion / contraction displacement due to temperature change, which may cause the position of each nozzle row 27 to deviate somewhat from the position before temperature change. The displacement of the ink landing position due to the displacement of the recording head 3 itself can be corrected by changing the ink ejection timing, more specifically, the timing of applying the drive signal to the pressure generating means.

Next, a second embodiment of the present invention will be described.
FIG. 8 is a diagram illustrating a configuration in the second embodiment.
In the configuration of the present embodiment, the fixing position of the head holder 25 and the frame member 34 in the first direction X, that is, the first fixing portion is set at the middle of the row of the recording heads 3a to 3d (second recording head 3b and third recording It differs from the first embodiment in that it is matched with the position corresponding to the head 3c).

  The distance in the first direction X from the first fixed portion as the reference B to the second support member 30b or the fourth nozzle row 27d of each recording head 3a to 3d is Pa to Pd, and the first direction of the head holder 25 is set. Assuming that the linear expansion coefficient at X is γ (1 / ° C.) and the linear expansion coefficients of the support members 30a and 30b are α and β (1 / ° C.), respectively, By determining the material, the material of the support members 30a, 30b, and the arrangement interval, a temperature change ΔT occurs, and the head holder 25 expands and contracts on both sides in the first direction X with the first fixed portion as the reference B. The recording heads 3 are tilted so that the nozzle forming surface 26 faces the first fixed portion due to the difference in displacement between the extending and contracting support members 30a and 30b. As a result, even when the head holder 25 expands and contracts due to a temperature change, the landing position deviation on the recording surface of the recording paper 4 is reduced before and after the temperature change around the head.

FIG. 9 is a diagram illustrating the configuration of the third embodiment of the present invention.
In the configuration of the present embodiment, the fixing position of the head holder 25 and the frame member 34 in the first direction X, that is, the first fixing portion is set to the position of the fourth nozzle row 27d of the fourth recording head 3d in the first direction X. The combined points differ from the above embodiments. The fourth recording head 3d is supported on the head holder 25 only by the first support member 30a without using the second support member 30b, because there is little deviation in the landing position of the ink due to thermal expansion of the head holder 25. The ink landing position is not corrected by the head tilt. Further, although not shown, an elongated hole as described in the first embodiment is provided at the end of the head holder 25 opposite to the first fixing portion in the first direction X, and the frame member 34 is provided. The fastening member from the side is loosely fitted without being fixed. That is, the head holder 25 is allowed to expand and contract in the first direction X toward the release end side (left side in FIG. 9) with the first fixed portion as a base point.

  As in the above embodiments, the distance in the first direction X from the first fixed portion as the reference B to each of the recording heads 3a to 3c is Pa to Pc, and the linear expansion coefficient of the head holder 25 in the first direction X is Assuming that γ (1 / ° C.) and the linear expansion coefficients of the support members 30a and 30b are α and β (1 / ° C.), respectively, the material of the head holder 25, the support member 30a, By determining the material, size, and arrangement interval of 30b, when the temperature change ΔT occurs and the head holder 25 expands and contracts in the first direction X (left side in FIG. 8) with the first fixed portion as the reference B, the same expands and contracts. Due to the difference in displacement between the support members 30a and 30b, the recording heads 3 are inclined so that the nozzle forming surface 26 faces the first fixed portion. As a result, even when the head holder 25 expands and contracts due to a temperature change, the landing position deviation on the recording surface of the recording paper 4 is reduced before and after the temperature change around the head.

  The arrangement layout of the unit heads 11 and the number of the recording heads 3 are not limited to those exemplified in the above embodiments, and any configuration can be adopted. Further, the fixing position and fixing method between the head holder 25 and the frame member 34 or the fixing method between the head holder 25, the support members 30a and 30b, and the recording head 3 are not limited to those exemplified.

  The present invention also relates to an electrode material ejection recording head iochip used for forming electrodes such as a color material ejection head, an organic EL (Electro Luminescence) display, and an FED (Surface Emitting Display) used for manufacturing a color filter such as a liquid crystal display. The present invention can also be applied to other liquid jet heads such as bioorganic jet heads used for manufacturing (biochemical elements) and liquid jet apparatuses including the same.

It is sectional drawing explaining the structure of a printer. FIG. 2 is a plan view around a recording head in a printer. It is the sectional view on the AA line in FIG. It is a figure explaining the attachment state of the recording head with respect to a head holder. It is a top view explaining the structure of a head holder. (A), (b) is an enlarged view explaining the attachment state of the recording head with respect to a head holder. (A), (b) is a schematic diagram explaining the inclination state of the recording head by extension of a supporting member. It is a figure explaining the structure in 2nd Embodiment. It is a figure explaining the structure in 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printer, 3 ... Recording head, 4 ... Recording paper, 7 ... Conveyance unit, 11 ... Unit head, 25 ... Head holder, 27 ... Nozzle row, 30a ... 1st support member, 30b ... 2nd support member, 34 ... Frame member

Claims (4)

A liquid ejecting head capable of ejecting liquid from a plurality of nozzle openings toward a liquid ejecting target;
A head holding member for holding the liquid jet head;
A liquid ejecting apparatus comprising:
The head holding member is fixed to the apparatus main body side with first fixing portions on both sides in a direction orthogonal to a relative feed direction between the jetting object and the liquid jet head during a liquid jetting operation,
The liquid ejecting head includes the first support member having a first linear expansion coefficient α and the second support member having a second linear expansion coefficient β larger than the first linear expansion coefficient α. Attached to the head holding member,
The liquid ejecting apparatus according to claim 1, wherein the first support member is disposed on a side farther than the second support member with respect to the first fixed portion in the relative feed direction.   While the liquid ejecting head disposed at a position farther in the relative feed direction than the first fixed portion narrows the interval between the first support member and the second support member, the liquid ejecting head narrows the distance relative to the first fixed portion. The liquid ejecting apparatus according to claim 1, wherein a distance between the first support member and the second support member is increased as the liquid ejecting head is disposed closer to the relative feed direction.   While the liquid ejecting head disposed at a position farther in the relative feed direction than the first fixed portion increases the difference between the first linear expansion coefficient α and the second linear expansion coefficient β, The liquid ejecting head disposed closer to the first fixed portion in the relative feed direction is configured to reduce the difference between the first linear expansion coefficient α and the second linear expansion coefficient β. 2. The liquid ejecting apparatus according to claim 1, wherein materials of the first support member and the second support member are made different according to an arrangement position of the liquid ejecting head with respect to the first fixing portion.   The first fixing portion is provided at a position corresponding to an intermediate portion of a plurality of liquid ejecting heads disposed on the head holding member at regular intervals in the relative feeding direction. The liquid ejecting apparatus according to claim 3.

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