JP3200446B2 - Print head of inkjet printer - Google Patents
Print head of inkjet printerInfo
- Publication number
- JP3200446B2 JP3200446B2 JP19744591A JP19744591A JP3200446B2 JP 3200446 B2 JP3200446 B2 JP 3200446B2 JP 19744591 A JP19744591 A JP 19744591A JP 19744591 A JP19744591 A JP 19744591A JP 3200446 B2 JP3200446 B2 JP 3200446B2
- Authority
- JP
- Japan
- Prior art keywords
- pressure chamber
- ink
- substrate
- grooves
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- B41J2202/00—Embodiments of or processes related to ink-jet or thermal heads
- B41J2202/01—Embodiments of or processes related to ink-jet heads
- B41J2202/10—Finger type piezoelectric elements
Landscapes
- Particle Formation And Scattering Control In Inkjet Printers (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明はプリンターに関し、更に
詳しくは圧電式インクジェットプリンターの印字ヘッド
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printer, and more particularly to a print head of a piezoelectric ink jet printer.
【０００２】[0002]
【従来の技術】従来の圧電式インクジェットプリンター
の印字ヘッドとしては、圧電素子のバイモルフによるた
わみを利用してインクを充填した圧力室の壁を変形さ
せ、圧力上昇によりインクを突出させるカイザー方式と
言われるものが例えば特公昭５７ー２０９０４号公報に
記載されている。2. Description of the Related Art A conventional print head of a piezoelectric ink-jet printer employs a Kaiser method in which the wall of a pressure chamber filled with ink is deformed by using the flexure of a piezoelectric element by a bimorph, and the ink is projected by an increase in pressure. What is described is described in, for example, Japanese Patent Publication No. 57-20904.
【０００３】また圧電素子のせん断モードによる変形を
利用して、インクを充填したチャンネル状の圧力室の隔
壁を変形させ、これによる圧力室の圧力上昇によりイン
クを突出させるせん断モード方式が例えば特開昭６３ー
２４７０５１号公報に記載されている。A shear mode system in which a partition of a channel-shaped pressure chamber filled with ink is deformed by utilizing the deformation of a piezoelectric element in a shear mode, and the ink is protruded by an increase in pressure of the pressure chamber due to this, for example, is disclosed in Japanese Patent Application Laid-Open No. H10-163,873. It is described in JP-A-63-247051.
【０００４】更に圧電素子の厚み方向の寸法変化による
変形を利用してインクを充填した圧力室の容積を変化さ
せ、これによる圧力室の圧力上昇によりインクを突出さ
せる厚み縦変形モード方式が例えば特願平２ー３０３９
５３５の願書に添付した明細書に記載されている。Further, a thickness vertical deformation mode system in which the volume of a pressure chamber filled with ink is changed by utilizing the deformation due to a dimensional change in the thickness direction of a piezoelectric element, and the ink is projected by a rise in the pressure of the pressure chamber, for example, is a special feature. Ganpei 2-3039
This is described in the specification attached to the 535 application.
【０００５】[0005]
【発明が解決しようとする課題】上記のすべての方式に
おいて、インクの乾燥等による吐出不良の根絶、圧電素
子の駆動電圧の低減、噴射手段の微細化はそれぞれイン
クジェットプリンターの信頼性の向上、装置の簡素化・
軽量化、印字パタンの分解能の向上のために要求される
ところである。しかし従来の技術をもってしてはこれら
の要求を満足させることは決して容易ではない。その根
本的な理由は、圧電駆動手段は力は出せても変位は出し
にくいという性質がある一方でインクの圧力を噴射する
までに高めるにはインクの圧縮比を上げるためインクを
充填した圧力室をかなり変形させなければならないとこ
ろにあると考えられる。つまり従来技術においては本来
的に駆動電圧のインク圧力への変換係数が低く、また噴
射手段の微細化により変換係数は下がる傾向にあるとい
うことから前記の問題が発生していると考えられる。か
かる根本的な課題を解決するため本発明は圧電式インク
ジェットプリンターの印字ヘッドにおいて圧電素子の駆
動電圧を上げることなく圧力室に充填されたインクの圧
力を従来よりも上げることを目的とする。In all of the above-mentioned methods, eradication of ejection failure due to drying of ink, reduction of the driving voltage of the piezoelectric element, and miniaturization of the ejection means improve the reliability of the ink jet printer, respectively. Simplification of
It is required to reduce the weight and improve the resolution of the printing pattern. However, it is not easy to satisfy these requirements with the conventional technology. The fundamental reason is that the piezoelectric driving means has the property that it can output force but hardly displaces, but in order to increase the pressure of the ink before ejecting it, the pressure chamber filled with ink to increase the compression ratio of the ink Is required to be considerably deformed. That is, in the prior art, the conversion coefficient of the drive voltage to the ink pressure is originally low, and the conversion coefficient tends to decrease due to the miniaturization of the ejection means. SUMMARY OF THE INVENTION In order to solve such a fundamental problem, an object of the present invention is to increase the pressure of the ink filled in the pressure chamber without increasing the drive voltage of the piezoelectric element in the print head of the piezoelectric ink-jet printer.
【０００６】[0006]
【課題を解決するための手段】前記課題を解決するため
に本発明のインクジェットプリンターの印字ヘッドは圧
電素子の駆動により充填したインクに圧力を加える圧力
室、該圧力室に設けられまたは取付けられた噴射導孔手
段及び該圧力室にインクを供給するインク供給手段を有
する圧電式インクジェットプリンターの印字ヘッドにお
いて前記圧力室内にガラス、セラミックス等のインクよ
り圧縮率の小なる物質よりなるスペーサーを配してなる
ことを特徴とするものである。In order to solve the above-mentioned problems, a print head of an ink jet printer according to the present invention is provided with a pressure chamber for applying pressure to ink filled by driving a piezoelectric element, and is provided or attached to the pressure chamber. In a print head of a piezoelectric ink jet printer having an ejection hole means and an ink supply means for supplying ink to the pressure chamber, a spacer made of a material having a lower compression ratio than ink such as glass, ceramics, etc. is arranged in the pressure chamber. It is characterized by becoming.
【０００７】[0007]
【作用】本構成によれば圧力室内のスペーサーの存在に
より該圧力室に充填されるインクの体積は減少し、しか
も圧電素子の駆動による圧力室の壁面の変形を妨害しな
いように充填物体を配しておけば圧力室の容積変化はそ
のものは従来と変わらないようにできる。ところで、ガ
ラス、セラミックス等の弾性係数の高い物質の圧縮率は
インクの１／１０から１／１００と低く、圧力室の圧縮
の際スペーサーの体積は縮小せず、インクの体積のみが
縮小するものと近似してもよい。従ってインクに着目す
ればその体積そのものは従来より減少しているにも拘ら
ず、その体積の圧電駆動時における減少分は、スペーサ
ー体積の減少が無視できるため、従来と変わらないこと
になり、この結果インクの体積変化率は従前のものより
増加する。ところで一般に液体が圧縮された場合には液
体の体積変化率に比例した圧力が発生するので本発明の
場合は圧電素子の駆動電圧を増加させることなく従前に
比し圧力室内のインクの圧力を高めることができる。ま
た圧力室内の体積変化量を一定に保ったまま圧力が高く
なるので副次的な効果としてインクの出入りの応答性が
速くなり高速印字に適するようになる。According to this structure, the presence of the spacer in the pressure chamber reduces the volume of ink filled in the pressure chamber, and furthermore, the filling object is arranged so as not to hinder the deformation of the wall of the pressure chamber due to the driving of the piezoelectric element. If so, the change in the volume of the pressure chamber can be made the same as before. By the way, the compression ratio of a substance having a high elastic modulus such as glass and ceramics is as low as 1/10 to 1/100 of that of ink. When the pressure chamber is compressed, the volume of the spacer does not decrease but only the volume of the ink decreases. May be approximated. Therefore, if attention is paid to ink, although the volume itself is smaller than in the past, the decrease in that volume during piezoelectric driving is the same as in the past because the decrease in the spacer volume can be ignored. As a result, the rate of volume change of the ink is increased over the previous one. In general, when a liquid is compressed, a pressure proportional to the volume change rate of the liquid is generated. Therefore, in the case of the present invention, the pressure of the ink in the pressure chamber is increased without increasing the driving voltage of the piezoelectric element. be able to. In addition, since the pressure is increased while the amount of change in volume in the pressure chamber is kept constant, as a secondary effect, the responsiveness of ink inflow and outflow is increased, which is suitable for high-speed printing.
【０００８】[0008]
【実施例１】以下に本発明の第１の実施例を図面に基づ
いて説明する。本実施例は圧電素子のせん断モードによ
る変形を利用して圧力室の隔壁を変形させる方式の印字
ヘッドにおける本発明の１実施例であり、図１（ａ），
図１（ｂ），図１（ｃ）及び図２に示す圧電性素材の基
板１に複数の圧力室を構成する溝３１，３２，３３及び
隔壁５１，５２が形成され、該隔壁の上端面は弾性部材
９を介して蓋６に結合されている。隔壁は図１の矢印の
方向に分極され、溝３１，３２，３３の内面にはそれぞ
れ電極４１，４２，４３が設けられている。圧力室を構
成する溝３１，３２，３３の一方の端に連結して図２に
示すようにインクを供給するための共通の溝８１が形成
され、ジョイント８２と連通して外部より圧力室にイン
クを供給する。前記圧力室の溝３１，３２，３３の他方
の端は基板１の一つの端面において開口しこの開口部を
塞ぐようにして基板１の前記の端面にノズル板６０が取
付られる。ノズル板６０には溝３１，３２，３３に対応
して噴射孔６１，６２，６３がそれぞれ設けられてい
る。各圧力室の内部にはガラスよりなるスペーサー９５
が若干のガタを生ずるような寸法のゆとりをもって配さ
れ、残りの隙間にはインクが充填される。スペーサー９
５は圧力室へのインクの出入りに従い壁面で規制される
範囲において移動でき、流体抵抗の増加を抑える作用を
するが、その端部は斜面となっており、壁面に当接した
時にインクの流路を塞がないようになっている。図１
（ａ）は前記の電極４１，４２，４３に電圧が印加され
る前の状態を示す。今電極４２に対し電極４１及び４２
に正の電圧を印加すると隔壁５１及び５２はそれぞれ図
１（ｂ）に示す如く紙面に平行な面において時計方向及
び反時計方向のせん断モードによる変形を起こす。この
結果溝３２により構成される圧力室９２の容積は減少し
充填されたインクの圧力が高まりノズル板６０に設けら
れた噴射孔６２よりインクを噴射する。Embodiment 1 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. This embodiment is an embodiment of the present invention in a print head of a type in which a partition of a pressure chamber is deformed by utilizing deformation of a piezoelectric element in a shear mode.
A plurality of grooves 31, 32, 33 and partition walls 51, 52 constituting pressure chambers are formed in the piezoelectric material substrate 1 shown in FIGS. 1 (b), 1 (c), and 2, and the upper end surface of the partition wall. Is connected to the lid 6 via an elastic member 9. The partition is polarized in the direction of the arrow in FIG. 1, and electrodes 41, 42, and 43 are provided on the inner surfaces of the grooves 31, 32, and 33, respectively. A common groove 81 for supplying the ink is formed as shown in FIG. 2 by being connected to one end of the grooves 31, 32, 33 constituting the pressure chamber, and communicates with a joint 82 to externally connect the pressure chamber to the pressure chamber. Supply ink. The other ends of the grooves 31, 32, and 33 of the pressure chamber are opened at one end face of the substrate 1, and a nozzle plate 60 is attached to the end face of the substrate 1 so as to close this opening. The nozzle plate 60 is provided with injection holes 61, 62, 63 corresponding to the grooves 31, 32, 33, respectively. A spacer 95 made of glass is provided inside each pressure chamber.
Are arranged with a margin enough to cause some backlash, and the remaining gaps are filled with ink. Spacer 9
Numeral 5 can move within the range regulated by the wall surface as ink flows into and out of the pressure chamber, and acts to suppress an increase in fluid resistance. However, its end is sloped, and ink flows when it comes into contact with the wall surface. The road is not blocked. FIG.
(A) shows a state before a voltage is applied to the electrodes 41, 42 and 43. Now, for the electrode 42, the electrodes 41 and 42
When a positive voltage is applied to the barrier ribs 51 and 52, the partition walls 51 and 52 are deformed in the clockwise and counterclockwise shear modes on a plane parallel to the paper surface as shown in FIG. As a result, the volume of the pressure chamber 92 formed by the groove 32 decreases, the pressure of the filled ink increases, and ink is ejected from the ejection holes 62 provided in the nozzle plate 60.
【０００９】図１（ｂ）の変形により溝幅Ｘなる圧力室
の隔壁の上端がΔＸだけ変位した場合、圧力室の容積を
Ｖ，容積の変化をΔＶとすると、容積変化率ΔＶ／Ｖは ΔＶ／Ｖ＝ΔＸ／Ｘ （１） となる。インクの圧縮比Ｆは図６に示す従来例の如く圧
力室内にスペーサー９５が存在しない場合は Ｆ＝ΔＶ／Ｖ （２） 本実施例のように圧力室内に体積Ｖ0 なるスペーサー９
５が存在する場合は、既に延べた理由により圧縮の際ス
ペーサーの体積Ｖ0 は変化しないとみなすと Ｆ＝ΔＶ／（ＶーＶ0 ） （３） となる。圧縮されたインクの圧力Ｐは圧縮比Ｆに比例
し、その体積弾性率をＢとすれば一般に Ｐ＝ＢＦ （４） で表される。（２），（３），（４）式より圧力室内に
充填物体が存在しない場合のインクの圧力Ｐ0 及び充填
物体が存在する場合の圧力Ｐ1を求めその比をとると Ｐ1 ／Ｐ0 ＝Ｖ／（Ｖ−Ｖ0 ） （５） の関係が得られる。（５）式よりインクの圧力は充填物
体の存在により増加し、しかも充填物体の体積Ｖ0 が増
大するに従って増加することがわかる。本実施例におい
ては充填物体の体積Ｖ0 は圧力室の容積Ｖの２／３にな
っており、インクの圧力を従来に比し３倍に拡大する効
果が得られた。また圧力室内の体積変化量を一定に保っ
たまま圧力が高くなるので副次的な効果としてインクの
出入りの応答速度が従来の３倍に向上した。When the upper end of the partition of the pressure chamber having the groove width X is displaced by ΔX due to the deformation of FIG. 1B, if the volume of the pressure chamber is V and the volume change is ΔV, the volume change rate ΔV / V is ΔV / V = ΔX / X (1) When the spacer 95 does not exist in the pressure chamber as in the conventional example shown in FIG. 6, the compression ratio F of the ink is: F = ΔV / V (2) The spacer 9 having a volume V 0 in the pressure chamber as in this embodiment.
In the case where No. 5 is present, if it is assumed that the volume V 0 of the spacer does not change during compression for the reason already extended, F = ΔV / (V−V 0 ) (3). The pressure P of the compressed ink is proportional to the compression ratio F, and if its bulk modulus is B, it is generally expressed as P = BF (4) From the formulas (2), (3), and (4), the ink pressure P 0 when no filling object is present in the pressure chamber and the pressure P 1 when the filling object is present are obtained, and the ratio is calculated as P 1 / P 0 = V / (V−V 0 ) (5) Equation (5) shows that the pressure of the ink increases due to the presence of the filling object, and also increases as the volume V 0 of the filling object increases. In this embodiment, the volume V 0 of the filling object is ／ of the volume V of the pressure chamber, and the effect of increasing the pressure of the ink three times as compared with the conventional case is obtained. In addition, since the pressure is increased while the amount of change in volume in the pressure chamber is kept constant, the response speed of ink inflow and outflow has been improved three times as compared with the related art as a secondary effect.
【００１０】[0010]
【実施例２】以下に本発明の第２の実施例を図面に基づ
いて説明する。本実施例も第１の実施例と同様に圧電素
子のせん断モードによる変形を利用して圧力室の隔壁を
変形させる方式の印字ヘッドにおける本発明の実施例で
あり、図５（ａ）及び図５（ｂ）に示す圧電性素材の基
板５０１に複数の圧力室を構成する溝５３１，５３２，
５３３及び隔壁５５１，５５２が形成され、該隔壁の上
端面は弾性部材５０９を介して蓋５０６に結合されてい
る。隔壁は図５（ａ）の矢印の方向に分極され、溝５３
１，５３２，５３３の内面にはそれぞれ電極５４１，５
４２，５４３が設けられている。圧力室を構成する溝５
３１，５３２，５３３の一方の端に連通して図５（ｂ）
に示すようにインクを供給するための共通の溝５８１が
形成され外部より圧力室にインクを供給する。前記圧力
室の溝５３１，５３２，５３３の他方の端は基板５０１
の一つの端面において開口しこの開口部を塞ぐようにし
て基板５０１の前記の端面にノズル板５６０が取付られ
る。ノズル板５６０には溝５３１，５３２，５３３に対
応して噴射孔５６１，５６２，５６３がそれぞれ設けら
れている。各圧力室の内部にはガラスよりなる球状のス
ペーサ５９５が若干のガタを生ずるような寸法のゆとり
をもって配され、残りの隙間にはインクが充填される。
蓋５０６にはストッパー５０３，５０４が設けられスペ
ーサー５９５を圧力室内に保持すると共に噴射孔を塞ぐ
ことがないようにする。本例における具体的な寸法につ
いては溝幅をｈ，深さをｄとした時 ｄ＝６０〜２５０μｍ ｈ：ｄ＝２〜３ が好ましい。今電極５４２に対し電極５４１及び５４２
に正の電圧を印加すると隔壁５５１及び５５２はそれぞ
れ実施例１で説明したのと全く同様に紙面に平行な面に
おいて時計方向及び反時計方向のせん断モードによる変
形を起こす。この結果溝５３２により構成される圧力室
の容積は減少し充填されたインクの圧力が高まりノズル
板５６０に設けられた噴射孔５６２よりインクを噴射す
る。この際図５（ｂ）において矢印の方向の流れに沿っ
て圧力が低下し圧力勾配を生ずので、スペサーはその両
側面の圧力差により矢印の方向に力を受けて流れに沿っ
て移動する。この結果インクはスペーサーが固着されて
いるいる場合のように、圧力室の壁とスペーサーの隙間
を無理に通過することなく、インクとスペーサーは一体
となって流れるため流体抵抗の増大を防ぐことが出来
る。なおインクの噴出後駆動電圧が解除され隔壁の変形
が復元される時は圧力室の圧力は外圧に対して負の圧力
となりインクの流れは矢印とは逆方向となりスーペーサ
ーも矢印とは逆方向に移動する。本実施例においてもス
ペーサー５９５の存在によりインクの圧縮比が高められ
実施例１と同様の原理によりインクの圧力を拡大すると
ともに出入りの応答速度を向上させることが出来る。Embodiment 2 Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. This embodiment is also an embodiment of the present invention in a print head of a type in which the partition of the pressure chamber is deformed by utilizing the deformation of the piezoelectric element in the shear mode similarly to the first embodiment, and FIG. 5b, grooves 531 and 532 constituting a plurality of pressure chambers are formed in a piezoelectric material substrate 501 shown in FIG.
533 and partition walls 551 and 552 are formed, and the upper end surface of the partition wall is connected to the lid 506 via an elastic member 509. The partition is polarized in the direction of the arrow in FIG.
Electrodes 541 and 5 are provided on the inner surfaces of 1,532 and 533, respectively.
42, 543 are provided. Groove 5 constituting pressure chamber
FIG. 5 (b)
As shown in (1), a common groove 581 for supplying ink is formed, and ink is supplied from outside to the pressure chamber. The other end of the pressure chamber grooves 531, 532, 533 is
A nozzle plate 560 is attached to the end surface of the substrate 501 so as to open at one end surface of the substrate 501 and close the opening. The nozzle plate 560 is provided with injection holes 561, 562, and 563 corresponding to the grooves 531, 532, and 533, respectively. Inside each pressure chamber, a spherical spacer 595 made of glass is arranged with a margin enough to cause some backlash, and the remaining gap is filled with ink.
The lid 506 is provided with stoppers 503 and 504 to hold the spacer 595 in the pressure chamber and not to block the injection hole. Regarding specific dimensions in this example, when the groove width is h and the depth is d, d = 60 to 250 μm h: d = 2 to 3 is preferable. Now, for the electrode 542, the electrodes 541 and 542
When a positive voltage is applied to the partition wall 551 and 552, deformation in the clockwise and counterclockwise shear modes occurs in a plane parallel to the paper in exactly the same manner as described in the first embodiment. As a result, the volume of the pressure chamber formed by the groove 532 decreases, the pressure of the filled ink increases, and the ink is ejected from the ejection holes 562 provided in the nozzle plate 560. At this time, since the pressure decreases along the flow in the direction of the arrow in FIG. 5B and a pressure gradient is generated, the spacer moves along the flow by receiving a force in the direction of the arrow due to the pressure difference between the two sides. . As a result, unlike the case where the spacer is fixed, the ink and the spacer flow together as a single piece without forcibly passing through the gap between the pressure chamber wall and the spacer, thereby preventing an increase in fluid resistance. I can do it. When the drive voltage is released after the ejection of the ink and the deformation of the partition is restored, the pressure in the pressure chamber becomes negative with respect to the external pressure, the ink flow is in the opposite direction to the arrow, and the spacer is also in the opposite direction to the arrow. Moving. Also in this embodiment, the compression ratio of the ink is increased by the presence of the spacer 595, so that the ink pressure can be increased and the response speed for entering and exiting can be improved by the same principle as in the first embodiment.
【００１１】[0011]
【実施例３】次に本発明の第３の実施例につき説明す
る。本実施例は圧電素子の屈曲モードによるたわみを利
用してインクを充填した圧力室の壁を変形させる方式の
印字ヘッドにおける本発明の実施例である。図３（ａ）
において基板２０１には圧力室を構成する溝２０６がつ
けられ、これにより圧力室の底部及び側壁部が形成され
る。側壁部のうち溝２０６の長手方向に直交する一方の
壁には噴射孔２０２が、他方の壁にはインクの導入管２
０５に連通する導入口２０３が設けられている。溝２０
６の中に溝よりも小さい寸法のセラミックスのビーズ状
のスペーサー２０９を入れた後側壁部の上に弾性材より
なる蓋２０４を被せ固着する。蓋２０４の外面には、一
面に電極２１２を他面に電極２１３を有し厚み方向に分
極された板状の圧電素子２１１が接合される。圧電素子
２１１自体は電極２１２に対し電極２１３に正の電圧を
加えた時に長手方向に圧縮力を発生するが、これが蓋２
０４の板に対しては中立軸のずれによりモーメントを発
生し図３（ｂ）に示す如く蓋２０４は屈曲モードの変形
を行い圧力室の容積を減少させることにより内部に充填
されたインクの圧力を高め噴射孔２０２よりインクを噴
射する。本実施例においてもスペーサー２０９の存在に
よりインクの圧縮比が高められ実施例１と同様の原理に
よりインクの圧力を拡大するとともに出入りの応答速度
を向上させることが出来る。Embodiment 3 Next, a third embodiment of the present invention will be described. This embodiment is an embodiment of the present invention in a print head of a system in which a wall of a pressure chamber filled with ink is deformed by using bending of a piezoelectric element in a bending mode. FIG. 3 (a)
In the substrate 201, a groove 206 constituting a pressure chamber is formed in the substrate 201, thereby forming a bottom portion and a side wall portion of the pressure chamber. The ejection hole 202 is provided on one wall of the side wall orthogonal to the longitudinal direction of the groove 206, and the ink introduction pipe 2 is provided on the other wall.
An introduction port 203 communicating with 05 is provided. Groove 20
A ceramic bead-shaped spacer 209 smaller than the groove is placed in the inside 6 and a lid 204 made of an elastic material is put on and fixed to the rear wall portion. A plate-shaped piezoelectric element 211 which has an electrode 212 on one surface and an electrode 213 on the other surface and is polarized in the thickness direction is joined to the outer surface of the lid 204. The piezoelectric element 211 itself generates a compressive force in the longitudinal direction when a positive voltage is applied to the electrode 213 with respect to the electrode 212.
For the plate No. 04, a moment is generated due to the displacement of the neutral axis, and as shown in FIG. 3B, the lid 204 deforms in a bending mode to reduce the volume of the pressure chamber, thereby reducing the pressure of the ink filled inside. And eject ink from the ejection holes 202. Also in this embodiment, the compression ratio of the ink is increased by the presence of the spacer 209, so that the ink pressure can be increased and the response speed for entering and exiting can be improved by the same principle as in the first embodiment.
【００１２】[0012]
【実施例４】次に本発明の第４の実施例について説明す
る。本実施例は圧電素子の厚み方向の寸法変化による変
形を利用してインクを充填した圧力室の容積を変化させ
る方式の印字ヘッドにおける本発明の実施例である。図
４（ａ）及び図４（ｂ）に示すように板状圧電体３２
０，３４０，３６０は圧力室３２１，３４１，３６１及
びこれらにそれぞれ連通するインク溜め３２２，３４
２，３６２が厚み方向に開放するようにくり抜かれてい
る。また隔壁板３３０，３５０はインク溜め３３２，３
５２が厚み方向に開放するようにくり抜かれている。板
状圧電体３２０，３４０，３６０の両面にはそれぞれ電
極３２５と３２６，３４５と３４６，３６５と３６６が
取り付けられ、該板状圧電体は矢印の方向に分極され
る。次に板状圧電体３２０，３４０，３６０と隔壁板３
３０，３５０は圧力室３２１，３４１、３６１の内部に
その寸法よりも小さい寸法のセラミックスよりなるスペ
ーサー３９０を適度なガタが得られる状態で入れた状態
で交互に順次積み重ねられ、インク溜め３２２，３３
２，３４２，３５２，３６２同志がそれぞれ対応するよ
うに積層配置して接合され、共通インク溜めを形成し、
更にこれらを挟んで上基板３８０と下基板３７０が取付
けられる。上基板３８０にはインク供給孔３８１が設け
られここよりインクが供給され共通インク溜め及び各圧
力室にインクを充填する。圧力室３２１，３４１，３６
１のインク溜めと反対側の端にはそれぞれに対応した噴
射孔３１１，３１２，３１３を有するノズル板３１０が
取付られている。今、板状圧電体３２０に取り付けられ
た電極３２５に対し正の電圧を電極３２６に加え矢印で
示す分極の方向と反対方向に電界を与えると板状圧電体
３２０の厚みは減少し面方向は厚み方向の圧縮率の略１
／３の伸び率で伸び、図４に示すように圧力室３２１の
断面は実線３２７から点線３２８に変わり、厚み方向の
寸法の減少率が長手方向の寸法の増加率を上回るため断
面積は減少し、従って圧力室３２１の容積が減少する。
この結果、圧力室内３２１内に充填されたインクの圧力
が高められ噴射孔３１１よりインクが噴射する。本実施
例においてもスペーサー３９０の存在によりインクの圧
縮比を上げ実施例１と同様の原理により圧力室に充填さ
れたインクの圧力を拡大することが出来る。Embodiment 4 Next, a fourth embodiment of the present invention will be described. This embodiment is an embodiment of the present invention in a print head of a system in which the volume of a pressure chamber filled with ink is changed by utilizing the deformation due to a dimensional change in the thickness direction of a piezoelectric element. As shown in FIGS. 4A and 4B, the plate-shaped piezoelectric body 32
Reference numerals 0, 340 and 360 denote pressure chambers 321, 341 and 361 and ink reservoirs 322 and 34 respectively communicating with the pressure chambers.
2,362 is hollowed out so as to release the opening in the thickness direction. The partition plates 330 and 350 have ink reservoirs 332 and 3 respectively.
52 is hollowed out so as to release the opening in the thickness direction. Electrodes 325, 326, 345, 346, 365 and 366 are attached to both surfaces of the plate-like piezoelectric members 320, 340 and 360, respectively, and the plate-like piezoelectric members are polarized in the directions of arrows. Next, the plate-like piezoelectric members 320, 340, 360 and the partition plate 3
30 and 350 are stacked alternately and sequentially with pressure spacers 321, 341, and 361 having spacers 390 made of ceramics having a size smaller than that of the pressure chambers 321, 341, and 361 inserted therein so as to obtain an appropriate play.
2, 342, 352, 362 are laminated and arranged so as to correspond to each other and are joined to form a common ink reservoir,
Further, the upper substrate 380 and the lower substrate 370 are attached with these components interposed therebetween. An ink supply hole 381 is provided in the upper substrate 380, from which ink is supplied, and the common ink reservoir and each pressure chamber are filled with ink. Pressure chambers 321, 341, 36
A nozzle plate 310 having ejection holes 311, 312, and 313 corresponding to the respective ink reservoirs is attached to the end opposite to the ink reservoir. Now, when a positive voltage is applied to the electrode 326 attached to the plate-shaped piezoelectric body 320 and an electric field is applied in a direction opposite to the direction of polarization indicated by the arrow, the thickness of the plate-shaped piezoelectric body 320 is reduced and the plane direction is changed. Approximately 1 in the compression ratio in the thickness direction
As shown in FIG. 4, the cross section of the pressure chamber 321 changes from a solid line 327 to a dotted line 328, and the cross-sectional area decreases because the rate of decrease in the dimension in the thickness direction exceeds the rate of increase in the dimension in the longitudinal direction. Therefore, the volume of the pressure chamber 321 decreases.
As a result, the pressure of the ink filled in the pressure chamber 321 is increased, and the ink is ejected from the ejection holes 311. Also in the present embodiment, the compression ratio of the ink can be increased by the presence of the spacer 390, and the pressure of the ink filled in the pressure chamber can be increased by the same principle as in the first embodiment.
【００１３】[0013]
【発明の効果】本発明によれば圧電式インクジェットプ
リンターにおいて駆動電圧及び駆動手段の諸元を変える
ことなく、またはこれらとは独立に圧力室に充填された
インクの駆動時の圧力を従来に比し格段に高めることが
できる。またインクの出入りの応答性を上げることが出
来る。従って本発明によれば従来この種のプリンタに課
題とされてきたインクの吐出不良の防止、駆動電源の電
圧の低下、印字パタンの分解能を上げるための噴射手段
の解決が出来るようになり、また、より高速な印字が出
来るようになり、その利とするところ極めて大である。According to the present invention, in a piezoelectric ink jet printer, the driving pressure of the ink filled in the pressure chamber can be reduced without changing the driving voltage and the driving means, or independently of them. And can be significantly increased. In addition, it is possible to increase the responsiveness of ink inflow and outflow. Therefore, according to the present invention, it becomes possible to solve the problem of the ink ejection failure which has conventionally been a problem in this type of printer, reduce the voltage of the drive power supply, and solve the ejection means for increasing the resolution of the print pattern. This makes it possible to perform printing at a higher speed, which is extremely advantageous.
【００１４】[0014]
【図１（ａ）】本発明の第１の実施例の構造を示す圧力
室の長手方向に垂直な断面図である。FIG. 1 (a) is a cross-sectional view perpendicular to the longitudinal direction of a pressure chamber showing a structure of a first embodiment of the present invention.
【図１（ｂ）】本発明の第１の実施例の動作を示す圧力
室の長手方向に垂直な断面図である。FIG. 1 (b) is a sectional view perpendicular to the longitudinal direction of the pressure chamber showing the operation of the first embodiment of the present invention.
【図１（ｃ）】本発明の第１の実施例の構造を示す圧力
室の長手方向に平行な断面図である。FIG. 1C is a cross-sectional view of the structure of the first embodiment of the present invention, which is parallel to the longitudinal direction of the pressure chamber.
【図２】本発明の第１の実施例の構造の一部を示す斜視
図である。FIG. 2 is a perspective view showing a part of the structure of the first embodiment of the present invention.
【図３（ａ）】本発明の第２の実施例の構造を示す断面
図である。FIG. 3 (a) is a sectional view showing the structure of a second embodiment of the present invention.
【図３（ｂ）】本発明の第２の実施例の動作を示す断面
図である。FIG. 3B is a sectional view showing the operation of the second embodiment of the present invention.
【図４（ａ）】本発明の第３の実施例の構造を示す分解
斜視図である。FIG. 4 (a) is an exploded perspective view showing a structure of a third embodiment of the present invention.
【図４（ｂ）】本発明の第３の実施例の構造を示す断面
図である。FIG. 4 (b) is a sectional view showing the structure of a third embodiment of the present invention.
【図４（ｃ）】本発明の第３の実施例の動作を示す説明
図である。FIG. 4C is an explanatory diagram showing the operation of the third embodiment of the present invention.
【図５（ａ）】本発明の第２の実施例の構造を示す圧力
室の長手方向に垂直な断面図である。FIG. 5 (a) is a cross-sectional view perpendicular to the longitudinal direction of a pressure chamber showing a structure of a second embodiment of the present invention.
【図５（ｂ）】本発明の第２の実施例を示す圧力室の長
手方向に平行な断面図である。FIG. 5 (b) is a cross-sectional view parallel to the longitudinal direction of a pressure chamber showing a second embodiment of the present invention.
【図６】従来例（本発明の第１の実施例に対応するも
の）の構造を示す断面図である。FIG. 6 is a sectional view showing the structure of a conventional example (corresponding to the first embodiment of the present invention).
１，５０１ 圧電性基板 ６，５０６，２０４ 蓋 ９，５０９ 弾性部材 ３１，３２，３３，５３１，５３２，５３３，２０６
溝 ４１，４２，４３，５４１，５４２，５４３，２１２，
２１３，３２５，３２６，３４５，３４６，３６５，３
６６ 電極 ５１，５２，５３，５１，５２，５３ 隔壁 ６０，５６０，３１０ ノズル板 ６１，６２，６３，５６１，５６２，５６３，２０２，
３１１，３１２，３１３噴射孔 ９５，５９５，２０９，３９０ スペーサー ２０１ 基板 ２０３ 導入孔 ２１１ 圧電素子 ３２０，３４０，３６０ 板状圧電体 ３２１，３４１，３６１ 圧力室 ３２２，３３２，３４２，３５２，３６０ インク溜め ３７０ 下基板 ３８０ 上基板1,501 Piezoelectric substrate 6,506,204 Lid 9,509 Elastic member 31,32,33,531,532,533,206
Grooves 41, 42, 43, 541, 542, 543, 212,
213,325,326,345,346,365,3
66 electrode 51,52,53,51,52,53 partition wall 60,560,310 nozzle plate 61,62,63,561,562,563,202,
311, 312, 313 injection holes 95, 595, 209, 390 spacer 201 substrate 203 introduction hole 211 piezoelectric element 320, 340, 360 plate-like piezoelectric body 321, 341, 361 pressure chamber 322, 332, 342, 352, 360 ink reservoir 370 Lower substrate 380 Upper substrate
Claims (2)
及び該複数の溝に連通しインクを供給する共通の溝を有
する圧電材料よりなる基板の上面に弾性部材を介して圧
力室の蓋となる上板を取付け、該基板の前記複数の溝の
開口する端面に該複数の溝のそれぞれに対応した噴射孔
を有するノズル板を取り付けてなり、該複数の溝には圧
電駆動用の電極をとりつけ、前記基板を厚み方向に分極
し、前記電極に駆動電圧を加えることにより隔壁をせん
断モードで変形させて圧力室の容積を変化させ、圧力室
内に充填したインクを噴射孔から射出する印字ヘッドに
おいて、圧力室内にガラス、セラミックス等のインクよ
り圧縮率の小なる物質よりなるスペーサーを配してなる
ことを特徴とするインクジェットプリンターの印字ヘッ
ド。1. A cover for a pressure chamber via an elastic member on an upper surface of a substrate made of a piezoelectric material having a plurality of grooves forming a pressure chamber and its partition wall and a common groove communicating with the plurality of grooves and supplying ink. A nozzle plate having an injection hole corresponding to each of the plurality of grooves is attached to an end surface of the substrate where the plurality of grooves are opened, and an electrode for piezoelectric driving is provided in the plurality of grooves. , The substrate is polarized in the thickness direction, and a driving voltage is applied to the electrodes to deform the partition walls in a shear mode, thereby changing the volume of the pressure chamber, and ejecting the ink filled in the pressure chamber from the ejection holes. A print head for an ink jet printer, wherein a spacer made of a substance having a lower compression ratio than ink such as glass or ceramics is disposed in a pressure chamber.
厚み方向に開放する圧力室を有し、かつ両面に駆動電極
を配し、厚み方向に分極した板状圧電体と隔壁板とを、
交互に複数個順次積層し、該圧力室と結合して噴射孔を
有するノズル板、及びインク供給手段を有し、前記駆動
電極に電圧を印加することによる前記板状圧電体の厚み
方向の寸法変化により圧力室の容積を変化させ、圧力室
内に充填したインクを噴射孔から射出する印字ヘッドに
おいて、圧力室内にガラス、セラミックス等のインクよ
り圧縮率の小なる物質よりなるスペーサーを配してなる
ことを特徴とするインクジェットプリンターの印字ヘッ
ド。2. An upper substrate and a lower substrate, and between the upper and lower substrates,
It has a pressure chamber to release the opening in the thickness direction, and disposed the driving electrodes on both sides, and polarized in a thickness direction piezoelectric plate and the partition plate,
A nozzle plate having a plurality of nozzles, each having a plurality of nozzles having an ejection hole in combination with the pressure chamber, and an ink supply unit, and a thickness dimension of the plate-shaped piezoelectric body when voltage is applied to the drive electrode. In a print head that changes the volume of the pressure chamber by the change and ejects the ink filled in the pressure chamber from the ejection hole, a spacer made of a material such as glass, ceramics, and the like having a smaller compression ratio than the ink is disposed in the pressure chamber. A print head for an ink jet printer, comprising:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19744591A JP3200446B2 (en) | 1991-07-12 | 1991-07-12 | Print head of inkjet printer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19744591A JP3200446B2 (en) | 1991-07-12 | 1991-07-12 | Print head of inkjet printer |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP32973099A Division JP3246905B2 (en) | 1999-11-19 | 1999-11-19 | Print head of inkjet printer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0516360A JPH0516360A (en) | 1993-01-26 |
| JP3200446B2 true JP3200446B2 (en) | 2001-08-20 |
Family
ID=16374628
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19744591A Expired - Fee Related JP3200446B2 (en) | 1991-07-12 | 1991-07-12 | Print head of inkjet printer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3200446B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007181990A (en) * | 2006-01-06 | 2007-07-19 | Matsushita Electric Ind Co Ltd | Liquid ejection head and liquid ejector |
-
1991
- 1991-07-12 JP JP19744591A patent/JP3200446B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0516360A (en) | 1993-01-26 |
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| Date | Code | Title | Description |
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| LAPS | Cancellation because of no payment of annual fees |