JP2015054509A - Liquid discharge head, and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid discharge head which can reduce a size of a head, and can reduce variation of droplet discharge characteristics between respective liquids supplied from a plurality of common liquid chambers arranged side by side.SOLUTION: A liquid is introduced to a first liquid introducing part 8A through a first introducing port 9A from a first common liquid chamber 10A, and a liquid is introduced to a second liquid introducing part 8B through a second introducing port 9B from a second common liquid chamber 10B. An array of the first introducing ports 9A and an array of the second introducing ports 9B are arranged in different positions in a direction orthogonal to a nozzle array direction. A length which determines fluid resistance of a flow channel from the second introducing port 9B of the second liquid introducing part 8B to a fluid resistance part 7 is longer than a length which determines fluid resistance of a flow channel from the first introducing port 9A of the first liquid introducing part 8A to the fluid resistance part. An opening cross sectional area which determines the fluid resistance of the flow channel from the second introducing port 9B of the second liquid introducing part 8B to the fluid resistance part is larger than an opening cross sectional area which determines the fluid resistance of the flow channel from the first introducing port 9A of the first liquid introducing part 8A to the fluid resistance part.

Description

  The present invention relates to a liquid discharge head and an image forming apparatus.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. Devices such as ink jet recording devices are known.

  As the liquid discharge head, ink is supplied from two common liquid chambers arranged side by side at odd-numbered and even-numbered pressure generating chambers arranged in a row, and ink supply ports from the common liquid chamber are arranged in a row. An arrangement is known (Patent Document 1).

  Further, there is also known one in which liquid is supplied from a plurality of common liquid chambers arranged in a stacked manner to the pressure generating chambers arranged in a row (Patent Document 2).

JP 2008-030354 A JP 2007-223190 A

  However, as described in Patent Document 1 described above, when the ink supply ports from the common liquid chamber to the pressure generation chamber are arranged in a row, the structure of the pressure generation chamber is the same, so the same ejection characteristics are obtained. It becomes possible to do.

  However, the plurality of common liquid chambers also need to have a skewered structure with the same arrangement pitch as the pressure generating chambers, and it is necessary to improve the accuracy of the common liquid chamber components (common liquid chamber members). There is a problem.

  Further, as described in Patent Document 2, in the structure in which a plurality of stacked common liquid chambers supply each pressure generating chamber, the shape of the ink supply hole from each common liquid chamber is constant. There is a problem that the discharge characteristics are different between adjacent pressure generation chambers.

  In this case, it is possible to cope with the drive control of the pressure generating means, but there is a problem that the drive circuit configuration is complicated and the cost is increased.

  The present invention has been made in view of the above-described problems. The head can be miniaturized with a simple configuration, and variations in droplet discharge characteristics between liquids supplied from a plurality of common liquid chambers arranged side by side. It aims at enabling it to reduce.

In order to solve the above-described problem, a liquid discharge head according to claim 1 of the present invention includes:
A plurality of nozzles for discharging droplets;
A plurality of individual liquid chambers leading to the nozzle;
A plurality of fluid resistance portions communicating with the individual liquid chambers;
A first common liquid chamber and a second common liquid chamber for supplying a liquid to each of the two individual liquid chambers arranged in the nozzle arrangement direction;
A first liquid introduction part that leads to the fluid resistance part and introduces a liquid from the first common liquid chamber via a first introduction port;
A second liquid introduction part that leads to the fluid resistance part and introduces a liquid from the second common liquid chamber via a second introduction port;
The plurality of nozzles are arranged in a line,
The first introduction port row and the second introduction port row are arranged at different positions in a direction orthogonal to the nozzle arrangement direction,
The length that determines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is the flow from the first introduction port of the first liquid introduction unit to the fluid resistance unit. Formed longer than the length that defines the fluid resistance of the path,
The opening cross-sectional area that defines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is from the first introduction port of the first liquid introduction unit to the fluid resistance unit. It was set as the structure formed wider than the opening cross-sectional area which defines the fluid resistance of a flow path.

  According to the present invention, it is possible to reduce the size of the head with a simple configuration, and it is possible to reduce variations in droplet discharge characteristics between the liquids supplied from a plurality of common liquid chambers arranged side by side.

FIG. 3 is an explanatory plan view of a main part of the liquid ejection head according to the first embodiment of the present invention. It is sectional explanatory drawing which follows the A1-A1 line | wire of FIG. FIG. 3 is a cross-sectional explanatory view taken along line B1-B1 of FIG. It is sectional explanatory drawing in alignment with a nozzle arrangement direction. FIG. 6 is an explanatory plan view of a main part of a liquid ejection head according to a second embodiment of the present invention. FIG. 6 is a cross-sectional explanatory view taken along line A2-A2 of FIG. FIG. 6 is a cross-sectional explanatory view taken along line B2-B2 of FIG. FIG. 10 is an explanatory plan view of a main part of a liquid ejection head according to a third embodiment of the present invention. FIG. 10 is an explanatory plan view of a main part of a liquid ejection head according to a fourth embodiment of the present invention. FIG. 10 is an explanatory plan view of a main part of a liquid ejection head according to a fifth embodiment of the present invention. It is principal part top explanatory drawing of the liquid discharge head which concerns on 6th Embodiment of this invention. It is principal part top explanatory drawing of the liquid discharge head which concerns on 7th Embodiment of this invention. FIG. 13 is an explanatory cross-sectional view taken along line A3-A3 of FIG. It is principal part top explanatory drawing of the liquid discharge head which concerns on 8th Embodiment of this invention. It is principal part top explanatory drawing of the liquid discharge head which concerns on 9th Embodiment of this invention. It is sectional explanatory drawing which follows the A4-A4 line | wire of FIG. It is sectional explanatory drawing which follows the B4-B4 line | wire of FIG. It is principal part top explanatory drawing of the liquid discharge head which concerns on 10th Embodiment of this invention. It is sectional explanatory drawing which follows the A5-A5 line | wire of FIG. It is sectional explanatory drawing which follows the B5-B5 line | wire of FIG. It is principal part plane explanatory drawing of the liquid discharge head which concerns on 11th Embodiment of this invention. It is principal part top explanatory drawing of the liquid discharge head which concerns on 12th Embodiment of this invention. It is sectional explanatory drawing which follows the A6-A6 line | wire of FIG. It is sectional explanatory drawing which follows the B6-B6 line | wire of FIG. FIG. 23 is a cross-sectional explanatory view taken along line C6-C6 of FIG. It is a principal part explanatory drawing of the liquid discharge head which concerns on 13th Embodiment of this invention. FIG. 27 is an explanatory cross-sectional view taken along line A7-A7 of FIG. It is principal part top explanatory drawing of the liquid discharge head which concerns on 14th Embodiment of this invention. It is a side explanatory view of a mechanism portion showing an example of an image forming apparatus according to the present invention. It is principal part plane explanatory drawing of the mechanism part.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. A liquid discharge head according to a first embodiment of the present invention will be described with reference to FIGS. 1 is an explanatory plan view of the main part of the head, FIG. 2 is an explanatory sectional view taken along line A1-A1 in FIG. 1, FIG. 3 is an explanatory sectional view taken along line B1-B1 in FIG. FIG.

  In the liquid discharge head, a nozzle plate 1, a flow path plate (flow path forming member) 2, and a vibration plate member 3 that is a wall surface member are laminated and joined. A piezoelectric actuator 11 that is a pressure generating means including a laminated piezoelectric element that displaces the diaphragm member 3 and a common liquid chamber member (common flow path member) 20 are provided.

  The nozzle plate 1 has a nozzle row in which a plurality of nozzles 4 for discharging droplets are arranged in a row.

  The flow path plate 2 includes a plurality of individual liquid chambers 6 through which the nozzles 4 communicate, a plurality of fluid resistance units 7 through which the individual liquid chambers 6 communicate, and a first liquid introduction unit 8A and a second liquid through which the fluid resistance units 7 communicate. The introduction part 8B (when not distinguished, it is simply referred to as “liquid introduction part 8”) is formed.

  The common liquid chamber member 20 includes a first common liquid chamber 10A that supplies liquid to one of two adjacent individual liquid chambers 6 that are two individual liquid chambers arranged in the nozzle arrangement direction, and two adjacent individual liquid chambers 6. And a second common liquid chamber 10B for supplying a liquid to the other of the two. The first common liquid chamber 10A and the second common liquid chamber 10B (simply referred to as “common liquid chamber 10” when not distinguished from each other) are arranged at different positions in the direction orthogonal to the nozzle arrangement direction.

  The diaphragm member 3 has a first introduction port 9A through which the first common liquid chamber 10A communicates and a second introduction port 9B through which the second common liquid chamber 10B communicates (hereinafter simply referred to as “introduction port 9”). And are formed.

  The rows of the first introduction ports 9A in the nozzle arrangement direction and the rows of the second introduction ports 9B in the nozzle arrangement direction are arranged at different positions in the direction orthogonal to the nozzle arrangement direction. The first introduction port 9A and the second introduction port 9B corresponding to two adjacent individual liquid chambers 6 are arranged at different positions in the nozzle arrangement direction, and are arranged in a staggered manner in this embodiment.

  A liquid is introduced from the first common liquid chamber 10A into the first liquid introduction part 8A through the first introduction port 9A. The liquid is introduced from the second common liquid chamber 10B into the second liquid introduction part 8B through the second introduction port 9B.

  The length (distance) L2 that defines the fluid resistance of the flow path from the second introduction port 9B of the second liquid introduction unit 8B to the fluid resistance unit 7 is the fluid from the first introduction port 9A of the first liquid introduction unit 8A. It is formed longer (L2> L1) than the length (distance) L1 that determines the fluid resistance of the flow path to the resistance portion 7.

  That is, the first introduction port 9A and the second introduction port 9B are arranged at different positions in the direction orthogonal to the nozzle arrangement direction, and the distance (length) from the introduction port 9 to the inlet of the fluid resistance unit 7 is the first The 1 introduction port 9A side is short, and the 2nd introduction port 9B side is long.

  On the other hand, the height H2 in the thickness direction of the flow path plate 2 of the second liquid introduction portion 8B is formed higher than the height H1 in the thickness direction of the flow path plate 2 of the first liquid introduction portion 8A (H2> H1). ing. That is, the opening cross-sectional area that determines the fluid resistance is wider in the second liquid introduction part 8B where the flow path length is longer than in the first liquid introduction part 8A.

  In this way, with respect to the fluid resistance of the flow path determined by the opening cross-sectional area and the length of the flow path, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7, The fluid resistance of the flow path from the second introduction port 9B of the two-liquid introduction part 8B to the fluid resistance part 7 is made the same or the difference is made small.

  Further, the flow path shapes of the individual liquid chamber 6 and the fluid resistance portion 7 are the same, and the fluid resistance is substantially the same (including the same) while the flow path shapes are different between the first liquid introduction portion 8A and the second liquid introduction portion 8B. Therefore, the droplet discharge characteristics from each nozzle 4 can be made substantially the same.

  Further, when different types of liquid are stored in the first common liquid chamber 10A and the second common liquid chamber 10B, the droplet discharge characteristics between the nozzles 4 that discharge different types of liquid can be made substantially the same. The plurality of types of liquids include, for example, liquids having different colors, dye-based and pigment-based liquids, and liquids having different characteristics such as photocurability.

  Accordingly, the head can be miniaturized with a simple configuration, and variations in droplet ejection characteristics between the liquids supplied from a plurality of common liquid chambers arranged side by side can be reduced.

  Next, specific examples and operations of each part of the liquid discharge head according to the present embodiment will be described.

  The nozzle plate 1 is formed of, for example, a nickel (Ni) metal plate and is manufactured by an electroforming method (electroforming). Not limited to this, other metal members, resin members, laminated members of resin layers and metal layers, and the like can be used. Further, a liquid repellent layer is provided on the droplet discharge side surface (surface in the discharge direction: discharge surface) of the nozzle plate 1.

  The flow path plate 2 is formed by etching a single crystal silicon substrate to form a groove portion and a through hole constituting the individual liquid chamber 6 and the liquid supply path. The flow path plate 2 can also be formed, for example, by etching a metal plate such as a SUS substrate with an acidic etching solution, or performing machining such as pressing.

  The vibration plate member 3 also serves as a wall surface member that forms the wall surface of the individual liquid chamber 6 of the flow path plate 2 and has a two-layer structure of the first layer 3A and the second layer 2B. Or a single layer structure. Here, there is a deformable vibration region 30 in a portion corresponding to the individual liquid chamber 6 by the first layer 3 </ b> A of the vibration plate member 3.

  The common liquid chamber member 20 also serves as a frame member of this head. In addition, a filter part can be provided in the 1st, 2nd inlet 9A, 9B of the diaphragm member 3 which leads to 1st, 2nd common liquid chamber 10A, 10B.

  The common liquid chamber member 20 is formed with a liquid supply port (not shown) that supplies liquid from a head tank or liquid cartridge (not shown) to the first common liquid chamber 10A and the second common liquid chamber 10B.

  The common liquid chamber member 20 is formed by injection molding with, for example, epoxy resin or thermoplastic resin such as polyphenylene sulfite.

  Then, on the opposite side of the diaphragm member 3 from the individual liquid chamber 6, a piezoelectric actuator 11 including an electromechanical conversion element as drive means (actuator means, pressure generating means) for deforming the vibration region 30 of the diaphragm member 3 is provided. It is arranged.

  This piezoelectric actuator 11 has a required number of columnar stacked piezoelectric elements (hereinafter referred to as “a”) formed by processing grooves by half-cut dicing on a piezoelectric member 12 which is a stacked piezoelectric element adhesively bonded to a base member (not shown). It is called a “piezoelectric column”.) 12A and 12B are formed in a comb shape at a predetermined interval.

  The piezoelectric column 12 </ b> A of the piezoelectric member 12 is adhesively bonded to the convex portion 31 of the vibration region 30 of the diaphragm member 3. The piezoelectric column 12 </ b> B is bonded to the diaphragm member 3 at a position corresponding to the partition between the individual liquid chambers 6.

  At this time, the piezoelectric pillars 12 </ b> A as pressure generating means are arranged in a line in the nozzle arrangement direction, like the nozzles 4.

  In addition, as the piezoelectric member 12, a piezoelectric layer and an internal electrode are laminated | stacked alternately, and an internal electrode is each pulled out to the end surface and the external electrode is provided. And FPC as a flexible wiring board which has flexibility for giving a drive signal to the external electrode of 12 A of piezoelectric pillars is connected.

  In the liquid discharge head configured as described above, for example, by lowering the voltage applied to the piezoelectric column 12A from the reference potential, the piezoelectric column 12A contracts, the vibration region 30 of the diaphragm member 3 is drawn, and the volume of the individual liquid chamber 6 is increased. As the liquid expands, the liquid flows into the individual liquid chamber 6.

  Thereafter, the voltage applied to the piezoelectric column 12A is increased to extend the piezoelectric column 12A in the stacking direction, and the vibration region 30 of the vibration plate member 3 is deformed in the nozzle 4 direction to contract the volume of the individual liquid chamber 6. As a result, the liquid in the individual liquid chamber 6 is pressurized, and droplets are ejected (jetted) from the nozzle 4.

  Then, by returning the voltage applied to the piezoelectric column 12A to the reference potential, the vibration region 30 of the diaphragm member 3 is restored to the initial position, and the individual liquid chamber 6 expands to generate a negative pressure. The liquid is filled into the individual liquid chamber 6 from the chamber 10 through the liquid introducing portion 8 and the fluid resistance portion 7. Therefore, after the vibration of the meniscus surface of the nozzle 4 is attenuated and stabilized, the operation proceeds to the next droplet discharge.

  Note that the driving method of the head is not limited to the above example (pulling-pushing), and it is also possible to perform striking or pushing depending on how the driving waveform is given.

  Next, a liquid ejection head according to a second embodiment of the present invention will be described with reference to FIGS. 5 is an explanatory plan view of the main part of the head, FIG. 6 is an explanatory sectional view taken along line A2-A2 of FIG. 5, and FIG. 7 is an explanatory sectional view taken along line B2-B2 of FIG.

  In the present embodiment, the width (hereinafter simply referred to as “width”) W2 of the second liquid introduction portion 8B in the nozzle arrangement direction is uniformly wider than the width W1 of the first liquid introduction portion 8A (W2> W1). Forming.

  Therefore, the opening cross-sectional area that determines the fluid resistance is wider in the second liquid introduction part 8B where the flow path length is longer than in the first liquid introduction part 8A.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the fluid resistance part 7 from the second introduction port 9B of the second liquid introduction part 8B The fluid resistance of the flow path is made the same or the difference is made small.

  Thereby, the same effect as the first embodiment can be obtained.

  Next, a liquid ejection head according to a third embodiment of the invention will be described with reference to FIG. FIG. 8 is an explanatory plan view of the main part of the head.

  In the present embodiment, the second liquid introduction part 8B is a part other than the downstream flow path part 8B1 adjacent to the first liquid introduction part 8A and the part adjacent to the first liquid introduction part 8A. An upstream channel portion 8B2 that is not adjacent to the portion 8A, and communicates with the second introduction port 9B at the most upstream portion of the upstream channel portion 8B2.

  The width of the upstream flow path portion 8B2 is made wider than the width of the downstream flow path portion 8B1 of the second liquid introduction portion 8B.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the fluid resistance part 7 from the second introduction port 9B of the second liquid introduction part 8B The fluid resistance of the flow path is made the same or the difference is made small.

  Thereby, the same effect as the first embodiment can be obtained.

  Next, a liquid ejection head according to a fourth embodiment of the invention will be described with reference to FIG. FIG. 9 is an explanatory plan view of the main part of the head.

  In the present embodiment, the second liquid introduction part 8B has a downstream flow path part 8B1 adjacent to the first liquid introduction part 8A and an upstream flow path part 8B2 not adjacent to the first liquid introduction part 8A. The upstream channel portion 8B2 communicates with each other to form one channel portion. The second introduction port 9B is provided for each individual liquid chamber 6 and communicates with the most upstream part of the upstream flow path part 8B2.

  And the width | variety of the downstream flow-path part 8B1 of the 2nd liquid introduction part 8B is made the same width as 8A of 1st liquid introduction parts.

  Thus, as a whole, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the fluid resistance part from the second introduction port 9B of the second liquid introduction part 8B. The fluid resistance of the flow path up to 7 is made the same or the difference is made small.

  Thereby, the same effect as the first embodiment can be obtained.

  Next, a liquid ejection head according to a fifth embodiment of the invention will be described with reference to FIG. FIG. 10 is an explanatory plan view of the main part of the head.

  The present embodiment includes a first common liquid chamber 10A, a second common liquid chamber 10B, and a third common liquid chamber 10C that supply liquid to three adjacent individual liquid chambers 6 respectively, and correspondingly. The first inlet 9A, the second inlet 9B, and the third inlet 9C, and the first liquid inlet 8A, the second liquid inlet 8B, and the third liquid inlet 8C are provided.

  The length L3 of the flow path from the third introduction port 9C to the fluid resistance unit 7 through which the third liquid introduction unit 8C communicates is from the second introduction port 9B to the fluid resistance unit 7 through which the second liquid introduction unit 8B communicates. The length L2 of the flow path from the second introduction port 9B to the fluid resistance portion 7 through which the second liquid introduction portion 8B communicates is longer than the length L2 of the flow channel (L3> L2). It is formed longer than the length L1 of the flow path to the fluid resistance portion 7 through which the liquid introduction portion 8A communicates (L2> L1).

  Therefore, the widths W3, W2, and W1 of the third, second, and second liquid introducing portions 8C, 8B, and 8A are set to have a relationship of W3> W2> W1, and the opening cross-sectional areas that determine the fluid resistance are varied.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the flow resistance from the second introduction port 9B of the second liquid introduction part 8B to the fluid resistance part 7 are described. The fluid resistance of the flow path and the fluid resistance of the flow path from the third introduction port 9C of the third liquid introduction part 8C to the fluid resistance part 7 are made the same or the difference is made small.

  Thereby, the same effect as the first embodiment can be obtained. Further, if different types of liquids are stored in the respective common liquid chambers, the variation in the discharge characteristics of the three types of liquids can be reduced by the configuration of the present embodiment.

  Next, a liquid ejection head according to a sixth embodiment of the invention will be described with reference to FIG. FIG. 11 is an explanatory plan view of the main part of the head.

  This embodiment also has a first common liquid chamber 10A, a second common liquid chamber 10B, and a third common liquid chamber 10C for supplying liquid to the three individual liquid chambers 6 arranged in the nozzle arrangement direction, respectively. Correspondingly, it has a first introduction port 9A, a second introduction port 9B and a third introduction port 9C, and a first liquid introduction part 8A, a second liquid introduction part 8B and a third liquid introduction part 8C.

  And here, the width of the downstream flow path part 8B1 of the second liquid introduction part 8B is made wider than the width of the first liquid introduction part 8A, and the width of the downstream flow path part 8B1 of the second liquid introduction part 8B. In addition, the width of the downstream flow path portion 8C1 of the third liquid introduction portion 8C is increased.

  Further, the width of the upstream flow path portion 8B2 of the second liquid introduction portion 8B is made wider than the width of the downstream flow path portion 8B1 of the second liquid introduction portion 8B. Similarly, the width of the intermediate flow path portion 8C2 of the third liquid introduction section 8C is made wider than the width of the downstream flow path section 8C1 of the third liquid introduction section 8C. Furthermore, the upstream flow path portion of the third liquid introduction portion 8C is in communication with each other.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the flow resistance from the second introduction port 9B of the second liquid introduction part 8B to the fluid resistance part 7 are described. The fluid resistance of the flow path and the fluid resistance of the flow path from the third introduction port 9C of the third liquid introduction part 8C to the fluid resistance part 7 are made the same or the difference is made small.

  Thereby, the same effect as that of the fifth embodiment can be obtained.

  Next, a liquid ejection head according to a seventh embodiment of the present invention will be described with reference to FIGS. 12 is an explanatory plan view of the main part of the head, and FIG. 13 is an explanatory sectional view taken along line A3-A3 of FIG.

  In the present embodiment, the configuration of the first embodiment is arranged so as to face the nozzle arrangement direction as a center so that four types of liquids can be discharged from the four common liquid chambers 10.

  This makes it possible to eject, for example, four colors of ink of black (K), cyan (C), magenta (M), and yellow (Y) with one head, and perform full color printing with one head. Can do.

  In addition, the nozzles 4a and 4c for ejecting four types of ink, 4c and 4d can be arranged in the same straight line in the direction orthogonal to the nozzle arrangement direction, and 4 on the same pixel on the paper surface by two scans. Various types of ink can be landed, and a high-quality image can be formed.

  Further, by arranging the individual liquid chambers 6 to face each other, the piezoelectric actuators 11 in each row can be arranged on one base member 13, so that one actuator unit can perform discharge for four colors. Accordingly, the head can be reduced in size and cost.

  Next, a liquid ejection head according to an eighth embodiment of the invention will be described with reference to FIG. FIG. 14 is an explanatory plan view of the main part of the head.

  In this embodiment, the nozzles 4a, 4b and 4c, 4d in the seventh embodiment are arranged in a staggered manner.

  By adopting such a configuration, it is possible to land four colors of inks of K, C, M, and Y at substantially the same place on the paper surface by one printing. Thus, it becomes possible to form a monochrome image and to perform printing at a higher speed.

  Next, a liquid ejection head according to a ninth embodiment of the invention will be described with reference to FIGS. 15 is an explanatory plan view of the main part of the head, FIG. 16 is an explanatory sectional view taken along line A4-A4 in FIG. 15, and FIG. 17 is an explanatory sectional view taken along line B4-B4 in FIG.

  In the present embodiment, the second liquid introduction portion 8B passing between the second common liquid chamber 10B and the individual liquid chamber 6 is disposed at the same position as the first liquid introduction portion 8A in the thickness direction of the flow path plate 2. The flow path part 88A and the flow path part 88B formed at a position different from the first liquid introduction part 8A in the thickness direction of the flow path plate 2 are provided.

  The flow path portion 88A of the second liquid introduction part 8B is formed in the same shape as the first liquid introduction part 8A.

  The flow path part 88B of the second liquid introduction part 8B has a larger opening cross-sectional area and a smaller flow path resistance than the first liquid introduction part 8A and the flow path part 88A. Here, the height of the flow path portion 88B (the height in the thickness direction of the flow path plate 2) is increased.

  For example, the flow path plate 2 is formed from a SUS plate having a three-layer structure, and the flow path portion 88A of the first liquid introduction part 8A and the second liquid introduction part 8B is formed in the first layer, and the second and third layers are formed. By forming the flow path portion 88B of the second liquid introduction part 8B, the opening cross-sectional area of the flow path portion 88B can be easily increased.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the flow resistance from the second introduction port 9B of the second liquid introduction part 8B to the fluid resistance part 7 are described. The fluid resistance of the flow path is made the same or the difference is made small.

  By comprising in this way, a different kind of liquid can be discharged from the nozzles 4 and 4 which adjoin.

  Further, the flow path shapes of the individual liquid chamber 6 and the fluid resistance portion 7 are the same, and the fluid resistance is substantially the same while the flow path shapes are different in the first liquid introduction portion 8A and the second liquid introduction portion 8B. The droplet discharge characteristics from each nozzle 4 can be made substantially the same.

  Thereby, it is possible to reduce the size of the head with a simple configuration, and it is possible to reduce variations in droplet discharge characteristics between the liquids supplied from a plurality of common liquid chambers arranged side by side.

  Next, a liquid ejection head according to a tenth embodiment of the present invention will be described with reference to FIGS. 18 is an explanatory plan view of the main part of the head, FIG. 19 is an explanatory sectional view taken along line A5-A5 in FIG. 18, and FIG. 20 is an explanatory sectional view taken along line B5-B5 in FIG.

  In the present embodiment, the flow path portion 88B of the second liquid introduction unit 8 is wider and lower in height than the ninth embodiment. Since the fluid resistance is determined by the opening cross-sectional area and the length, the fluid resistance can be reduced as in the ninth embodiment.

  For example, in the present embodiment, the flow path plate 2 uses a silicon substrate and forms a flow path by etching.

  And, when forming the flow path in the flow path plate 2, in order to prevent the warpage of the substrate and the adhesive from protruding, a dummy recess is formed on the surface opposite to the side where the individual liquid chamber 6 is formed. The channel portion 88B can be formed by the recess etching process. Thereby, the flow path width of the flow path part 88B can be easily widened. Further, in the thickness direction of the flow path plate 2, when the flow path connecting the individual liquid chamber 6 and the nozzle 4 is formed by etching, the flow path part 88a connecting the flow path part 88B and the flow path part 88A and the second introduction. A flow path portion 88b connecting the opening 9B can be formed.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the flow resistance from the second introduction port 9B of the second liquid introduction part 8B to the fluid resistance part 7 are described. The fluid resistance of the flow path is made the same or the difference is made small.

  Thereby, the same effect as that of the ninth embodiment can be obtained.

  Next, a liquid ejection head according to an eleventh embodiment of the present invention will be described with reference to FIG. FIG. 21 is an explanatory plan view of the main part of the head.

  In the present embodiment, the flow path portion 88B of the second liquid introduction portion 8B communicates with each other to form one flow path portion. The second introduction port 9B is provided for each individual liquid chamber 6 and communicates with the most upstream portion of the flow path portion 88B.

  Thus, as a whole, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the fluid resistance part from the second introduction port 9B of the second liquid introduction part 8B. The fluid resistance of the flow path up to 7 and the fluid resistance of the flow path from the third introduction port 9C of the third liquid introduction part 8C to the fluid resistance part 7 are made the same or the difference is made small.

  Thereby, the same effect as that of the ninth embodiment can be obtained.

  Next, a liquid ejection head according to a twelfth embodiment of the present invention will be described with reference to FIGS. 22 is an explanatory plan view of the main part of the head, FIG. 23 is an explanatory sectional view taken along the line A6-A6 in FIG. 22, FIG. 24 is an explanatory sectional view taken along the line B6-B6 in FIG. It is a section explanatory view which meets a C6-C6 line.

  The present embodiment includes a first common liquid chamber 10A, a second common liquid chamber 10B, and a third common liquid chamber 10C that supply liquid to three adjacent individual liquid chambers 6 respectively, and correspondingly. The first inlet 9A, the second inlet 9B, and the third inlet 9C, and the first liquid inlet 8A, the second liquid inlet 8B, and the third liquid inlet 8C are provided.

  The second liquid introduction portion 8B passing between the second common liquid chamber 10B and the individual liquid chamber 6 has a flow path portion 88A disposed at the same position as the first liquid introduction section 8A in the thickness direction of the flow path plate 2. The flow path plate 2 has a flow path portion 88B formed at a position different from the first liquid introduction part 8A in the thickness direction of the flow path plate 2.

  The third liquid introduction part 8C passing between the third common liquid chamber 10C and the individual liquid chamber 6 is a flow path part 88A arranged at the same position as the first liquid introduction part 8A in the thickness direction of the flow path plate 2. The flow path plate 2 has a flow path portion 88C formed at a position different from the first liquid introduction portion 8A in the thickness direction of the flow path plate 2.

  The width of the flow path portion 88B of the second liquid introduction section 8B is wider than the width of the first liquid introduction section 8A, and the width of the flow path section 88C of the third liquid introduction section 8C is the second liquid introduction section. The width of the channel portion 88B of 8B is wider.

  In this way, the fluid resistance of the flow path from the first introduction port 9A of the first liquid introduction part 8A to the fluid resistance part 7 and the flow resistance from the second introduction port 9B of the second liquid introduction part 8B to the fluid resistance part 7 are described. The fluid resistance of the flow path and the fluid resistance of the flow path from the third introduction port 9C of the third liquid introduction part 8C to the fluid resistance part 7 are made the same or the difference is made small.

    Thereby, the same effect as that of the ninth embodiment can be obtained. Further, if different types of liquids are stored in the respective common liquid chambers, the variation in the discharge characteristics of the three types of liquids can be reduced by the configuration of the present embodiment.

  Next, a liquid ejection head according to a thirteenth embodiment of the invention will be described with reference to FIGS. FIG. 26 is an explanatory plan view of the main part of the head, and FIG. 27 is an explanatory sectional view taken along line A7-A7 of FIG.

  In the present embodiment, the configuration of the tenth embodiment is arranged so as to face the nozzle arrangement direction as a center so that four types of liquids can be discharged from the four common liquid chambers 10.

  This makes it possible to eject, for example, four colors of ink of black (K), cyan (C), magenta (M), and yellow (Y) with one head, and perform full color printing with one head. Can do.

  In addition, the nozzles 4a and 4c for ejecting four types of ink, 4c and 4d can be arranged in the same straight line in the direction orthogonal to the nozzle arrangement direction, and 4 on the same pixel on the paper surface by two scans. Various types of ink can be landed, and a high-quality image can be formed.

  Further, by arranging the individual liquid chambers 6 to face each other, the piezoelectric actuators 11 in each row can be arranged on one base member 13, so that one actuator unit can perform discharge for four colors. Accordingly, the head can be reduced in size and cost.

  Next, a liquid ejection head according to a fourteenth embodiment of the present invention will be described with reference to FIG. FIG. 28 is an explanatory plan view of the main part of the head.

  In the present embodiment, the nozzles 4a, 4b and 4c, 4d in the thirteenth embodiment are arranged in a staggered pattern.

  By adopting such a configuration, it is possible to land four colors of inks of K, C, M, and Y at substantially the same place on the paper surface by one printing. Thus, it becomes possible to form a monochrome image and to perform printing at a higher speed.

  Next, an example of the image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 29 is an explanatory side view of the mechanism portion of the apparatus, and FIG. 30 is an explanatory plan view of an essential part of the mechanism portion.

  This image forming apparatus is a serial type image forming apparatus. The carriage 233 is slidably held in the main scanning direction by main and slave guide rods 231 and 232 which are guide members horizontally mounted on the left and right side plates 221A and 221B, and the direction of the arrow is indicated by a main scanning motor (not shown) via a timing belt. Move and scan in the carriage main scanning direction.

  The carriage 233 is mounted with a recording head 234 including the liquid ejection head according to the present invention that ejects ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). .

  In addition, a head tank 235 for each color is connected to the recording head 234, and ink for each color is replenished and supplied from each color ink cartridge 210 to each head tank 235 via a supply tube 236 for each color.

  On the other hand, as a paper feeding unit for feeding the paper 242 stacked on the paper stacking unit (pressure plate) 241 of the paper feed tray 202, a half-moon roller (feeding) that separates and feeds the paper 242 one by one from the paper stacking unit 241. Paper roller) 243 and a separation pad 244 facing the paper feed roller 243. The separation pad 244 is urged toward the sheet feeding roller 243 side.

  A guide 245 for guiding the paper 242, a counter roller 246, a conveyance guide member 247, and a tip pressure roller 249 are used to feed the paper 242 fed from the paper feeding unit to the lower side of the recording head 234. And a pressing member 248 having Further, a transport belt 251 is provided as a transport unit for electrostatically attracting the fed paper 242 and transporting it at a position facing the recording head 234.

  The conveyor belt 251 is an endless belt, and is configured to wrap around the conveyor roller 252 and the tension roller 253 so as to circulate in the belt conveyance direction (sub-scanning direction). In addition, a charging roller 256 that is a charging unit for charging the surface of the transport belt 251 is provided. The charging roller 256 is disposed so as to come into contact with the surface layer of the conveyor belt 251 and to rotate following the rotation of the conveyor belt 251. The transport belt 251 rotates in the belt transport direction when the transport roller 252 is rotationally driven through timing by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 242 recorded by the recording head 234, a separation claw 261 for separating the paper 242 from the transport belt 251, a paper discharge roller 262, and a paper discharge roller 263 are provided. A paper discharge tray 203 is provided below the paper discharge roller 262.

  A double-sided unit 271 is detachably attached to the back surface of the apparatus main body. The duplex unit 271 takes in the paper 242 returned by the reverse rotation of the transport belt 251, reverses it, and feeds it again between the counter roller 246 and the transport belt 251. The upper surface of the duplex unit 271 is a manual feed tray 272.

  Further, a maintenance / recovery mechanism 281 for maintaining and recovering the nozzle state of the recording head 234 is disposed in a non-printing area on one side in the scanning direction of the carriage 233. The maintenance / recovery mechanism 281 includes a cap 282 for capping each nozzle surface of the recording head 234. Further, the maintenance and recovery mechanism 281 includes a wiper blade 283 that is a blade member for wiping the nozzle surface, and a liquid used when performing an idle discharge for discharging a liquid droplet that does not contribute to recording in order to discharge the thickened recording liquid. An empty discharge receiver 284 for receiving droplets is provided.

  Further, in the non-printing area on the other side in the scanning direction of the carriage 233, there is an empty space for receiving a liquid droplet when performing an empty discharge for discharging a liquid droplet that does not contribute to the recording in order to discharge the recording liquid thickened during the recording. A discharge receiver 288 is disposed. The idle discharge receiver 288 includes an opening 289 along the nozzle row direction of the recording head 234 and the like.

  In this image forming apparatus configured as described above, the sheets 242 are separated and fed one by one from the sheet feeding tray 202, and the sheet 242 fed substantially vertically upward is guided by the guide 245, and is conveyed to the conveyor belt 251 and the counter. It is sandwiched between the rollers 246 and conveyed. Further, the leading edge of the sheet 242 is guided by the conveying guide 237 and pressed against the conveying belt 251 by the leading end pressure roller 249, and the conveying direction is changed by about 90 °.

  When the paper 242 is fed onto the charged transport belt 251, the paper 242 is attracted to the transport belt 251, and the paper 242 is transported in the sub-scanning direction by the circular movement of the transport belt 251.

  Therefore, by driving the recording head 234 according to the image signal while moving the carriage 233, ink droplets are ejected onto the stopped paper 242 to record one line, and after the paper 242 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 242 has reached the recording area, the recording operation is finished and the paper 242 is discharged onto the paper discharge tray 203.

  As described above, the image forming apparatus includes the liquid discharge head according to the present invention as a recording head, and thus can be reduced in size.

  In the present application, “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, and the like, and can be attached to ink droplets and other liquids. This includes recording media, recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics or the like. In addition, “image formation” not only applies an image having a meaning such as a character or a figure to a medium but also applies an image having no meaning such as a pattern to the medium (simply applying a droplet to the medium). It also means to land on.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically. For example, DNA samples, resists, pattern materials, resins and the like are also included.

  In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

DESCRIPTION OF SYMBOLS 1 Nozzle plate 2 Flow path plate 3 Vibration plate member 4 Nozzle 6 Individual liquid chamber 7 Fluid resistance part 8A 1st liquid introduction part 8B 2nd liquid introduction part 8C 3rd liquid introduction part 9A 1st liquid introduction port 9B 2nd liquid introduction Port 9C Third liquid introduction port 10A First common liquid chamber 10B Second common liquid chamber 10C Third common liquid chamber 12 Piezoelectric member 12A Piezoelectric column 20 Common liquid chamber member 233 Carriage 234 Recording head

Claims (8)

A plurality of nozzles for discharging droplets;
A plurality of individual liquid chambers leading to the nozzle;
A plurality of fluid resistance portions communicating with the individual liquid chambers;
A first common liquid chamber and a second common liquid chamber for supplying a liquid to each of the two individual liquid chambers arranged in the nozzle arrangement direction;
A first liquid introduction part that leads to the fluid resistance part and introduces a liquid from the first common liquid chamber via a first introduction port;
A second liquid introduction part that leads to the fluid resistance part and introduces a liquid from the second common liquid chamber via a second introduction port;
The plurality of nozzles are arranged in a line,
The first introduction port row and the second introduction port row are arranged at different positions in a direction orthogonal to the nozzle arrangement direction,
The length that determines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is the flow from the first introduction port of the first liquid introduction unit to the fluid resistance unit. Formed longer than the length that defines the fluid resistance of the path,
The opening cross-sectional area that defines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is from the first introduction port of the first liquid introduction unit to the fluid resistance unit. A liquid discharge head, wherein the liquid discharge head is formed wider than an opening cross-sectional area that defines a fluid resistance of a flow path. The second liquid introduction part has a width in the nozzle arrangement direction of a part other than the part adjacent to the first liquid introduction part than the width in the nozzle arrangement direction of the part adjacent to the first liquid introduction part. The liquid discharge head according to claim 1, wherein the liquid discharge head is characterized in that 2. The liquid ejection head according to claim 1, wherein portions of the plurality of second liquid introduction portions facing the second introduction ports communicate with each other in a nozzle arrangement direction. A flow path plate that forms the individual liquid chamber, the fluid resistance section, and the liquid introduction section;
2. The liquid according to claim 1, wherein the second liquid introduction part has a flow path part formed at a position different from the first liquid introduction part in the thickness direction of the flow path plate. Discharge head. 5. The liquid discharge head according to claim 1, wherein the first common liquid chamber and the second common liquid chamber are arranged at different positions in a direction orthogonal to a nozzle arrangement direction. . Pressure generating means for pressurizing the individual liquid chamber;
6. The liquid discharge head according to claim 1, wherein the plurality of pressure generating units corresponding to the plurality of individual liquid chambers are arranged in a line in a nozzle arrangement direction. A plurality of nozzles for discharging droplets;
A plurality of individual liquid chambers leading to the nozzle;
A plurality of fluid resistance portions communicating with the individual liquid chambers;
A first common liquid chamber, a second common liquid chamber, and a third common liquid chamber for supplying a liquid to each of the three individual liquid chambers arranged in the nozzle arrangement direction;
A first liquid introduction part that leads to the fluid resistance part and introduces a liquid from the first common liquid chamber via a first introduction port;
A second liquid introduction part that leads to the fluid resistance part and introduces a liquid from the second common liquid chamber via a second introduction port;
A third liquid introduction part that leads to the fluid resistance part and introduces a liquid from the third common liquid chamber via a third introduction port;
The plurality of nozzles are arranged in a line,
The first introduction port row, the second introduction port row, and the third introduction port row are arranged at different positions in a direction orthogonal to the nozzle arrangement direction,
The length that determines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is the flow from the first introduction port of the first liquid introduction unit to the fluid resistance unit. Formed longer than the length that defines the fluid resistance of the path,
The opening cross-sectional area that defines the fluid resistance of the flow path from the second introduction port of the second liquid introduction unit to the fluid resistance unit is from the first introduction port of the first liquid introduction unit to the fluid resistance unit. Formed wider than the opening cross-sectional area that defines the fluid resistance of the flow path,
The length that defines the fluid resistance of the flow path from the third introduction port of the third liquid introduction unit to the fluid resistance unit is the flow from the second introduction port of the second liquid introduction unit to the fluid resistance unit. Formed longer than the length that defines the fluid resistance of the path,
The opening cross-sectional area that defines the fluid resistance of the flow path from the third introduction port of the third liquid introduction unit to the fluid resistance unit is from the second introduction port of the second liquid introduction unit to the fluid resistance unit. A liquid discharge head, wherein the liquid discharge head is formed wider than an opening cross-sectional area that defines a fluid resistance of a flow path.   An image forming apparatus comprising the liquid discharge head according to claim 1.

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