JP2006088689A - Recording head and recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording head which can prevent a liquid in ejection outlets from drying over a long period even when a state in which the liquid is not ejected lasts. <P>SOLUTION: A recording head 50 has a channel forming member 5 in which an ejection outlet 7 for ejecting the liquid is formed and an element substrate 1 in which a heater 2 is formed. A gap forming member 12 is disposed above the channel forming member 5. A moisture-retention liquid retaining unit 8 retaining a moisture retention liquid for retaining moisture in the vicinity of the ejection outlet 7 is formed between the gap forming member 12 and the channel forming member 5 so as to be open toward the ejection outlet 7 side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a recording head and a recording apparatus that perform recording on a recording medium by discharging a liquid. In particular, the present invention relates to a recording head and a recording apparatus having a structure that prevents the discharge port from being clogged by moisturizing the periphery of the discharge port.

  A liquid discharge recording head and a liquid discharge recording apparatus (hereinafter simply referred to as “recording head” and “recording apparatus”) having the same have various problems due to drying of ink (liquid).

  For example, if the period during which ink is not ejected becomes long, the moisture in the ink evaporates through the ejection port, resulting in thickening of the ink in the ejection port or a solid film on the surface of the meniscus at the ejection port. It may be formed. In this way, when ink thickening or film formation occurs, the ink flow resistance increases and the discharge speed decreases, or the discharge direction is inclined from a predetermined direction due to the influence of the solid film. This causes a malfunction in the discharge operation.

  In addition, such a malfunction of the ejection operation that occurs when ink is dried by not ejecting ink for a long period of time may be referred to as a “problem occurrence problem”. Further, such a problem is particularly likely to be a problem in recent recording heads in which the discharge ports and ink droplets are miniaturized in order to improve image quality.

  Conventionally, countermeasures have been taken against the above-mentioned problems by adopting the configuration shown in FIGS. FIG. 5A is a top view, and FIG. 5B is a cross-sectional view taken along a cutting line A in FIG.

  In the recording head 150 of FIG. 5, a hydrophilic treatment portion 115 subjected to a hydrophilic treatment is partially formed on the surface (discharge port surface) of a flow path forming member 105 provided as an orifice plate. As shown in the top view of FIG. 5A, the hydrophilic treatment unit 115 is disposed so as to be located on both sides of the discharge port array formed by the plurality of discharge ports 107.

  When the recording head 150 configured as described above is mounted and used in a known recording apparatus having a head suction recovery mechanism, ink is held in the hydrophilic processing unit 115 and remains when the suction recovery operation is performed. . Then, the ink held in the hydrophilic processing unit 115 in this way is gradually evaporated thereafter, so that the humidity around the ejection port 107 is kept high. Accordingly, the evaporation of ink from the ejection port 107 is suppressed, and the period until the malfunction of the ejection operation as described above can be lengthened. In other words, it is possible to lengthen the period until the “issue problem” occurs (also referred to as “time to issue”).

  Next, the recording head 250 in FIG. 6 will be described. 6A is a top view, and FIG. 6B is a cross-sectional view taken along a cutting line A in FIG. 6A.

  In the recording head 250, a liquid holding groove 205 a is formed in the vicinity of the ejection port 207 so as to dig the flow path forming member 205 and open toward the upper surface side. In the liquid holding groove 205a, a moisturizing liquid such as ink is held in a liquid state, and when the liquid evaporates, the humidity around the discharge port 207 is kept high.

A recording head in which a region subjected to a hydrophilic treatment is formed on the ejection port surface as in the recording head 150 of FIG.
JP 2002-331678 A

  However, the configuration shown in FIG. 5 has the following problems.

  (1) Since the area of the hydrophilic treatment unit 115 is large with respect to the amount of liquid retained in the hydrophilic treatment unit 115, the evaporation rate of the retained liquid is fast, and therefore, the periphery of the discharge port is kept highly humid for a long period of time. Is difficult.

  (2) If the surface of the flow path forming member 105 is wiped using a wiping member, the liquid held in the hydrophilic treatment unit 115 is also wiped together, and the effect of the hydrophilic treatment unit 115 cannot be obtained.

  Note that the problem (1) can be improved somewhat by increasing the area of the hydrophilic treatment portion 115. However, the size of the head itself is increased, and the effect of the improvement is so great. Absent.

  Further, the configuration shown in FIG. 6 has the following problems.

  (3) The liquid holding groove 205 a is formed so as to dig the flow path forming member 205, and therefore the depth thereof is limited to the thickness of the flow path forming member 205. As a result, the amount of liquid that can be held in the liquid holding groove 205a cannot be increased. This means that the period until the liquid in the liquid holding groove 205a completely evaporates is short, and as a result, it is difficult to maintain the periphery of the discharge port at a high humidity for a long time.

  On the other hand, for example, increasing the number of the liquid holding grooves 205a or widening the opening of one liquid holding groove 205a may slightly improve the above problem, but may lead to the problem of an increase in the size of the head as described above. There is. Even if the number of grooves is increased or the opening is widened, the opening is away from the vicinity of the discharge port, so that the improvement effect cannot be expected so much.

  Accordingly, an object of the present invention is to provide a recording head and a recording apparatus that can prevent the liquid in the discharge port from drying for a long period of time even when the state in which the liquid is not discharged continues.

  In order to achieve the above object, a recording head according to the present invention has an energy generating element that generates energy used for ejecting a liquid and a discharge port surface provided with a discharge port for discharging a liquid. A flow path forming member that forms a flow path that communicates with the outlet, and a gap that is disposed so as to provide a gap between the discharge port surface, except for a position facing the discharge port surface and corresponding to the discharge port And the gap is communicated with an opening that opens in a direction toward the discharge port, and a moisturizing liquid is supplied to the gap.

  According to the recording head of the present invention, the moisturizing liquid is held near the discharge port by capillary force, and the moisturizing liquid near the discharge port becomes an evaporation source. That is, the humidity near the discharge port can be suitably maintained with a very simple configuration without requiring a special device such as an evaporator. By maintaining the humidity in the vicinity of the discharge port, drying of the liquid in the discharge port can be prevented over a long period of time. Further, according to the recording apparatus of the present invention using such a recording head, it is possible to minimize the occurrence of a malfunction in the ejection operation when the liquid ejection is resumed after the state in which the liquid is not ejected continues. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In this specification, “recording” should be interpreted widely as well as forming significant information such as characters and graphics. In detail, regardless of whether it is significant involuntary, or whether it is manifested so that it can be perceived by human eyes, a wide variety of images, patterns, patterns, etc. are formed on the recording medium, or the medium. The case where the above processing is performed is also shown.

  “Recording medium” refers not only to paper used in general recording apparatuses but also widely to cloth, plastic film, metal plate, glass, ceramics, wood, leather, and the like that can accept ink. Shall.

  Further, “ink” and “liquid” should be interpreted broadly as in the definition of “recording”. Specifically, there are some which are used for forming an image, a pattern, a pattern, or the like or processing a recording medium by being applied on the recording medium. Specifically, it is used for general ink for printing characters and images, materials used for forming wiring patterns, and ink processing (for example, solidification or insolubilization of colorant in ink applied to a recording medium). It shall represent the liquid obtained.

(First embodiment)
FIG. 8 is a schematic perspective view showing a schematic configuration of a liquid discharge recording apparatus to which the head of the present invention can be applied. In FIG. 8, a head 38 for discharging a liquid such as ink is positioned and mounted on the main scanning carriage 36. The main scanning carriage 36 is guided and supported so as to be reciprocally movable along the main scanning rail 37, and is reciprocated in the main scanning direction (direction of the main scanning rail 37) by a driving source (not shown).

  A recording material 30 such as a recording paper is fed into the apparatus main body by a paper feed roller 31 and is sandwiched between a paper feed roller (conveying roller) 32 by a pinch roller (not shown) and a paper pressing plate 33. By controlling the rotation of the paper feed roller 32, a position (recording position) with a predetermined gap from the front surface of the recording means (recording head) constituted by the head 38 (the head surface provided on the lower surface in the illustrated example). ) Is fed (conveyed). In the meantime, by driving the recording head 1 based on the recording information, an image (including characters and the like) is recorded (printed). A home position HP of the main scanning carriage is set at a position within the moving range of the main scanning carriage 36 and out of the recording area (right end portion in the drawing).

  In the vicinity of the home position HP, a capping means having a cap made of a rubber-like elastic material capable of sealing the discharge port by contacting (contacting) the head surface of the head 38 (surface on which the discharge port is formed). Is arranged. In addition, suction means including a suction pump capable of generating a negative pressure suction force at the discharge port through the cap in the capped state is also disposed. Further, a head recovery device 35 including a cleaning unit including a cleaning member for scraping (wiping off) an adhering matter such as ink and dust by rubbing against the head surface of the head 38 is also provided. The head recovery device 35 generates a negative pressure in the cap by a suction pump in a state where the ejection port portion of the head is capped. By this negative pressure, foreign matter such as thickened ink, bubbles, fixed ink, and dust is sucked out and discharged together with ink from the discharge port, thereby executing a recovery operation for recovering the ink discharge performance of the head.

  1A and 1B show the configuration of a recording head according to a first embodiment of the present invention. FIG. 1A is a view from the top of the head, and FIG. 1B is the view of FIG. It is sectional drawing in the cutting line A. FIG. The cutting line A is a line that cuts along a plane that passes through the center of the discharge port and intersects the discharge port surface and the opening portion perpendicularly.

  A recording head 50 shown in FIG. 1 is a known general type of recording head of this type, except that a gap forming member 12 is disposed above the flow path forming member 5 (in the direction of discharging the liquid). It has a configuration. That is, in the recording head 50, the flow path forming member 5 is disposed as an orifice plate on the element substrate 1 on which the heater 2 is formed, and the flow path forming member 5 is disposed between the element substrate 1 and the flow path forming member 5. 6 is formed. A heater 2 is formed in the flow path 6 to generate bubbles by applying thermal energy to a liquid such as ink, and to discharge ink by the bubbles. A part of the surrounding area functions as a pressure chamber. A discharge port 7 is formed at a position corresponding to the heater 2 on the surface (discharge port surface) of the flow path forming member 5. As shown in FIG. 1A, a plurality of discharge ports 7 are formed so as to be arranged in a line at a predetermined pitch. In other words, one discharge port array is constituted by the plurality of discharge ports 7. In the present embodiment, only one ejection port array is provided, but the present invention can also be applied to a head in which two or more ejection port arrays are formed.

  Next, the gap forming member 12 and its peripheral structure will be described.

  One gap forming member 12 is made of a flat plate-like member, and is arranged one by one on both sides of the discharge port array. Further, as shown in FIG. 1A, the discharge port side end portion 12a of the gap forming member 12 is parallel to the discharge port array at a certain distance. In the present embodiment, the peripheral structure of the gap forming member 12 is symmetrical with respect to the ejection port array. Further, as shown in FIG. 1B, the gap forming member 12 is arranged with a certain distance (gap) from the discharge port surface (upper surface) of the flow path forming member 5.

  By disposing the gap forming member 12 in this way, the moisturizing liquid holding portion 8 for holding the moisturizing liquid is configured as a flat gap between the gap forming member 12 and the flow path forming member 5. . The moisturizing liquid holding unit 8 has an opening 8a that opens toward the discharge port 7, and the opening 8a is parallel to the discharge port array. More specifically, although only a part thereof is shown in FIG. 1 (a), the opening 8a has a long shape in a range that opens to all the discharge ports 7 formed. It is formed with. As a result, substantially uniform moisturization can be performed on the periphery of any of the discharge ports 7.

  Further, in FIG. 1, a structure for supporting the gap forming member 12 is not shown, but for example, the end of the gap forming member 12 on the side away from the discharge port 7 is supported by a support member (not shown). It may be done. Alternatively, ribs or bosses may be provided between the gap forming member 12 and the flow path forming member 5 to support the gap forming member 12. Thereby, the space | gap formation member 12 is supported more stably, and mechanical strength also improves. Thus, when providing a rib and a boss and improving the structural stability of the space | gap formation member 12, it is made to prevent the volume of the moisturizing liquid holding | maintenance part 8 from becoming too small by providing a rib and a boss. desirable.

  As shown in FIG. 1B, the moisturizing liquid is held in the moisturizing liquid holding unit 8 when the recording head 50 is used. The moisturizing liquid only needs to be capable of moisturizing the periphery of the ejection port 7 by evaporating. For example, the moisturizing liquid may be the same as the liquid ejected, and may be any of ink, water, or ink excluding dye It may be.

  Next, the size of each part of the head applicable to the present invention will be described.

  As shown in FIG. 9, the height of the moisturizing liquid holding part (distance from the discharge port surface to the gap forming member) is h, the diameter of the discharge port is φ, and the moisturizing liquid holding part is installed on both sides of the discharge port. Let W be the interval.

  Since the evaporation amount depends on the area of the liquid surface, it is necessary that “the opening area of the discharge port ≦ the opening area of the opening 8a of the moisturizing liquid holding portion”. In order to further enhance the moisturizing effect, it is preferable that “the diameter of the discharge port φ ≦ the height h of the moisturizing liquid holding portion”. The diameter φ of the discharge port is set according to the size of the liquid to be discharged. When the droplet to be discharged is about 0.5 pl, φ is about 6 μm. When the droplet to be discharged is about 2 pl, φ is about 10.5 to 12 μm. When the droplet to be discharged is about 5 pl, φ is about 16 μm.

  Moreover, the manufacturing process can be simplified by aligning the height h of the moisturizing liquid holding portion with the height H of the flow path 6. A general flow path height H is about 10 μm to 20 μm.

  Next, the interval W between the moisturizing liquid holding portions disposed on both sides of the discharge port will be described.

  When the value of W is large, the opening surface 8a having the moisturizing liquid moves away from the discharge port, and the moisturizing effect is reduced.

  The ratio of the moisture diffused by evaporation of the moisturizing liquid in the air near the discharge port and the ratio of the water evaporated from the discharge port in the vicinity of the discharge port in the absence of the moisturizing liquid are approximately equal. If present, evaporation at the discharge port can be ideally suppressed. For example, when the diameter of the discharge port is 6 μm and the height h of the moisturizing liquid moisturizing portion is 1000 μm, the moisturizing effect to the extent that the discharge defect is improved is obtained when the interval W is 300 μm or less. If it is 100 μm or less, it is possible to suppress evaporation ideally. In general, as the diameter of the discharge port becomes smaller, defective discharge due to drying becomes more conspicuous. Therefore, it is preferable that the moisturizing liquid holding unit corresponding to the small discharge port is closer to the discharge port.

  Furthermore, when the interval W is too small, there is a possibility that the moisturizing liquid and the liquid for discharge are connected as shown in FIG. This is also related to the pressure (negative pressure) in the tank in which the liquid for discharge is held. Therefore, as shown in FIG. 10B, a description will be given of the configuration of the head so that the moisturizing liquid and the liquid such as the ejection ink are not connected.

  In FIG. 11, the enlarged view of moisturizing liquid holding | maintenance part and discharge port vicinity is shown.

  Let E be the end of the surface of the gap forming member 12 (the surface facing the recording medium), and F be the end of the discharge port formed on the discharge port surface D of the flow path forming member 5. Because of the cross-sectional view, E and F are indicated by dots. A circle having a radius R0 passing through the points E and F is defined as a circle C. Let L be the distance from the discharge port surface D to the surface of the gap forming member 12. L is obtained by adding the thickness of the gap forming member to the height h of the gap.

  If the negative pressure in the tank is small, the liquid surface leaves point F when the ink in the nozzle is sucked out and replaced, and the moisturizing liquid and the ink are connected. At this time, if the circle indicating the liquid level passing through the point E is a circle M and the radius thereof is Rm, the radius Rm of the circle M is larger than the radius of the circle C. On the other hand, when the negative pressure in the tank is large, the radius Rm of the circle M decreases and approaches the radius of the circle C. When the negative pressure in the tank further increases, the radius Rm of the circle M becomes smaller than the radius of the circle C.

At this time, the form as shown in FIG. 10B can be maintained without the moisturizing liquid surface and the ink liquid surface being connected. When this condition is expressed by an expression, expression (1) is obtained.
Rm <R0 Formula (1)
Here, when the pressure (force received from the ink) acting on the meniscus (liquid surface) indicated by the circle M due to the negative pressure in the tank is P, and the surface tension of the liquid such as the ejected ink is γ,
P = (γ / Rm) (2)
The relationship is established. From equations (1) and (2),
(Γ / P) <R0 Formula (3)
The following relational expression is derived. As shown in FIG. 11, the value of R0 on the right side of Equation (3) is the diameter φ of the discharge port, the interval W between the moisturizing liquid holding portions arranged on both sides of the discharge port, and the height h of the gap. The left side is determined by the surface tension of the ink and the negative pressure in the tank. Therefore, by using a head, ink, and tank having a configuration of φ, W, and L that satisfy the expression (3), as shown in FIG. Each meniscus is held independently without being connected.

  According to the recording head configured as described above, the moisturizing liquid holding portion that holds the moisturizing liquid for moisturizing the periphery of the discharge port is disposed between the gap forming member disposed above the discharge port surface and the discharge port surface. It is formed as a void portion. By appropriately changing the size of the gap forming member, it is possible to form a moisturizing liquid holding part capable of holding a large amount of moisturizing liquid. Therefore, as an effect that a large amount of moisturizing liquid can be retained in the moisturizing liquid retaining part, it is possible to retain the periphery of the discharge port for a long period of time.

  A method for supplying the moisturizing liquid into the moisturizing liquid holding unit 8 will be described below.

(1) Method of Using the Suction Recovery Mechanism of the Recording Device As shown in FIG. 4A, when the recording device includes the suction recovery mechanism 11, the moisturizing liquid holding portion of the recording head 50 using that mechanism. Ink can be held as a moisturizing liquid in the inside 8. As an operation for that purpose, first, the cap 11 a of the suction recovery mechanism 11 is brought into contact with the surface side of the recording head 50. Specifically, the cap 11a is in contact with the surface of the air gap forming member 12 (the surface facing the recording medium) in the recording head 50, and at least a portion of the recording head 50 where the ejection port 7 is formed and holding the moisturizing liquid. It is formed so as to cover both the openings 8 of the portion 8. Then, the pump of the suction recovery device 11 connected to the cap is driven to forcibly suck ink from the ejection port 7. Ink overflowing from the ejection port 7 in such a recovery operation is held in a space formed between the gap forming member 12 and the cap. Thus, the overflowed ink is drawn into the moisturizing liquid holding unit 8 by capillary force, and as a result, the ink is held in the moisturizing liquid holding unit 8 as a moisturizing liquid.

(2) Method of Using Moisturizing Liquid Supply Mechanism Provided in Recording Apparatus This method is a new moisturizing liquid supply mechanism 10 for supplying moisturizing liquid into the recording apparatus, as shown in FIG. The moisturizing liquid is supplied into the moisturizing liquid holding unit 8 by using the same.

  Examples of such a moisturizing liquid supply mechanism include the following. A storage container for holding a moisturizing liquid made of ink or the like excluding water and dye, and a passage member for transferring the moisturizing liquid in the container into the moisturizing liquid holding section 8 (for example, a tubular member 10a such as a tube). And a pump or the like provided in the middle of the passage member. In this case, in the configuration shown in FIG. 1, a connection portion may be formed at the end of the moisturizing liquid holding portion 8 on the side away from the discharge port 7, and the passage member may be connected to the connection portion. Good. Further, if necessary, a sensor or the like for detecting the remaining amount of the moisturizing liquid in the moisturizing liquid holding unit 8 may be provided and used.

  The moisturizing liquid supply mechanism configured as described above is driven at a predetermined timing when the remaining amount of the moisturizing liquid in the moisturizing liquid holding unit 8 is reduced. That is, by driving the pump of the moisturizing liquid supply mechanism, the moisturizing liquid in the storage container is supplied into the moisturizing liquid holding unit 8 via the passage member.

  Since the method (1) conventionally uses a suction recovery mechanism equipped in the recording apparatus, it has an advantage in that a special mechanism for supply as in (2) is not required. . Moreover, since the method (2) supplies the moisturizing liquid in the storage container, it has an advantage in that various moisturizing liquids suitable for moisturizing can be used without being limited to ink.

  According to the recording head 50 of the present embodiment configured as described above, the moisturizing liquid holding unit 8 is formed between the gap forming member 12 and the surface (discharge port surface) of the flow path forming member 5. Since the volume of the moisturizing liquid holding unit is larger than that of the conventional configuration shown in FIG. 6, for example, a larger amount of moisturizing liquid can be held. As a result, the periphery of the discharge port 7 can be moisturized for a longer period. The moisturizing liquid holding unit 8 has a flat shape, and the moisturizing liquid is stably held by the capillary force between the gap forming member 12 and the flow path forming member 5. The opening 8a of the moisturizing liquid holding unit 8 opens in the horizontal direction (direction parallel to the discharge port surface) toward the discharge port 7 side. As a result, the periphery of the discharge port 7 can be moisturized more effectively than the conventional configuration shown in FIG. 6 that opens in the direction perpendicular to the discharge port surface (the direction toward the upper surface). It will be a thing. In addition, the openings 8 are formed so as to be open to all the discharge ports 7 and the distances between the discharge ports 7 and the openings 8 are constant. A substantially uniform moisture retention is possible with respect to the discharge port 7.

  The configuration of the recording head 50 described above can be variously changed. For example, in order to supply ink into the moisturizing liquid holding unit 8, the moisturizing liquid holding unit 8 and a supply liquid chamber (not shown) of the recording head 50 may be communicated with each other. Alternatively, the moisturizing liquid holding unit 8 and the ink tank of the recording apparatus may be communicated with each other. Here, the common liquid chamber is a structure portion that is formed in the element substrate 1 and stores ink supplied into the flow path 6.

(Second Embodiment)
A description of the same parts as in the first embodiment, such as the structure of the apparatus, is omitted.

  FIG. 2 is a diagram showing a configuration of a recording head according to the second embodiment of the present invention. FIG. 2A is a top view, and FIG. 2B is a cross-sectional view taken along a cutting line A in FIG.

  The recording head 51 shown in FIG. 2 has a communication port 12b formed in the gap forming member 12 in addition to the configuration of the recording head 50 shown in FIG. The other structure is the same as that of the recording head 50 of FIG. 1, and the same reference numerals as in FIG.

  The communication port 12b is formed in a state of penetrating the gap forming member 12, and is formed so as to be one long slot as shown in the top view of FIG. Since the communication port 12b is formed in this way, the moisturizing liquid holding portion 8b is partially opened toward the discharge port 7 side and partially opened toward the surface side of the gap forming member 12. It has a shape. FIG. 2 shows a state in which the moisturizing liquid is held in the moisturizing liquid holding unit 8b.

  According to the recording head 51 of the present embodiment configured in this way, the moisturizing liquid in the moisturizing liquid holding part 8b can be sucked and discharged through the communication port 12b. It has the advantage that the exchange of the moisturizing liquid in 8b becomes easy.

  This replacement operation may be performed by the following operation using the suction recovery mechanism as described above, for example. In this case, the moisturizing liquid is ink. First, the cap of the suction recovery mechanism is brought into contact with the surface side of the recording head 51. When the pump is driven, the ink is forcibly sucked from the discharge port 7 and the ink in the moisturizing liquid holding portion 8b is also sucked from the communication port 12b. As a result, the old ink held in the moisturizing liquid holding unit 8b is discharged, while the ink overflowing from the ejection port 7 by this suction operation is drawn into the moisturizing liquid holding unit 8b. By such an operation, the moisturizing liquid (ink) in the moisturizing liquid holding unit 8b is replaced.

  When ink is used as the moisturizing liquid, since the water in the ink held in the moisturizing liquid holding part 8b evaporates with time, the performance of the ink in the moisturizing liquid holding part 8b as the moisturizing liquid gradually decreases. I will do it. On the other hand, the configuration in which the ink in the moisturizing liquid holding unit 8b can be easily replaced as in the present embodiment is that the ink having a high water concentration can be held in the moisturizing liquid holding unit 8b. Has advantages.

  In addition, the shape of the communication port 12b provided in the space | gap formation member 12 can be variously changed, for example, as shown in FIG. FIG. 3A is a top view, and FIG. 3B is a cross-sectional view taken along a cutting line A in FIG.

  In the recording head 52 of FIG. 3, the communication port 12c is provided in a state of several through holes independent from each other, and the total opening area of these communication ports 12c is smaller than the opening area of the supply port 12b of FIG. It has become a thing. According to the recording head 52 configured as described above, in addition to the advantages of the recording head 51, the amount of ink evaporated from the communication port 12c can be suppressed by reducing the total opening area of the communication port 12c. Is obtained. This means that wasteful evaporation of the ink in the moisturizing liquid holding unit can be minimized and the periphery of the ejection port 7 can be moisturized for a long period of time.

(Third embodiment)
A description of the same parts as in the first embodiment, such as the structure of the apparatus, is omitted.

  In the recording head 50 of the above-described embodiment, two moisturizing liquid holding portions 8 are formed on both sides with the ejection port 7 interposed therebetween. However, the present invention is not limited to this, and the moisturizing liquid holding portion 8 is provided only on one side. It may be formed. Such an example is shown in FIG. In this case, an advantage can be obtained when wiping the surface side of the recording head 50 with a wiping member made of an elastic member 66 such as rubber.

  That is, the case where the wiping member is configured to move in the horizontal direction shown in FIG. 1 to wipe the surface of the recording head 50 will be described.

  The wiping member is moved from one side where the moisturizing liquid holding part 8 is formed toward the other side where the moisturizing liquid holding part 8 is not formed (in the direction of the arrow in FIG. 7). Then, the wiping member first wipes the surface of the gap forming member 12, and after the wiping member exceeds the end portion 8a of the gap forming member 12, the surface (discharge port face) of the flow path forming member 5 is wiped.

  Thereby, the discharge outlet 7 and its periphery are kept in a clean state. As described above, if the moisturizing liquid holding portion 8 is formed only on one side, the ejection port surface of the head can be wiped well even in the structure having the moisturizing liquid holding portion 8.

  In the conventional configuration shown in FIGS. 5 and 6, the liquid for moisturizing is scraped by wiping. Further, there is a possibility that dust or the like is clogged in the upper end opening of the liquid holding groove 205a (see FIG. 6) due to wiping. However, the liquid holding unit 8 of the present embodiment is configured to be hardly affected by wiping.

1 is a diagram illustrating a configuration of a recording head according to a first embodiment of the invention. It is a figure which shows the structure of the recording head of the 2nd Embodiment of this invention. It is a figure which shows the structure of the recording head by the other example of 2nd Embodiment. (A) Schematic using a suction recovery mechanism as moisturizing liquid supply means (b) Schematic using a moisturizing liquid supply mechanism as moisturizing liquid supply means. FIG. 10 is a diagram illustrating an example of a configuration of a conventional recording head. It is a figure which shows the other example of a structure of the conventional recording head. It is a figure which shows the structure of the recording head of the 3rd Embodiment of this invention. 1 is a diagram showing a schematic configuration of a liquid discharge recording apparatus to which a head of the present invention can be applied. It is an enlarged view of the vicinity of the discharge port of the first and second embodiments of the present invention. (A) The figure which the liquid for discharge and the moisturizing liquid were mixed and connected (b) The figure which the liquid for discharge and the moisturizing agent are not connected. FIG. 4 is an enlarged view of the vicinity of an opening formed by a discharge port of the head of the present invention and a gap forming portion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Element board | substrate 2 Heater 5 Flow path formation member 6 Flow path 7 Ejection port 8, 8b Moisturizing liquid holding | maintenance part 8a Opening part 10 Moisturizing agent supply apparatus 12 Gap formation member 12b, 12c Communication port 20 Recording apparatus 50, 51, 52 Recording head

Claims (10)

An energy generating element that generates energy used to discharge the liquid;
A flow path forming member having a discharge port surface provided with a discharge port for discharging a liquid and forming a flow channel communicating with the discharge port;
A gap-forming member disposed so as to be opposed to the discharge port surface and provided with a gap between the discharge port surface except for a position corresponding to the discharge port;
The recording head according to claim 1, wherein the gap communicates with an opening that opens in a direction toward the ejection port, and a moisturizing liquid is supplied to the gap.   2. The recording head according to claim 1, further comprising an ejection port array including a plurality of ejection ports, wherein the opening is formed in a long length parallel to the ejection port array.   The recording head according to claim 2, wherein the openings are located on both sides of the ejection port array, and the openings are opposed to each other.   4. The air gap forming member is formed with a communication port penetrating the air gap forming member, and the air gap communicates with the surface side of the air gap forming member through the communication port. Any one of the recording heads.   The recording head according to claim 1, wherein an area of the opening is larger than an area of the discharge port.   The recording head according to claim 5, wherein a distance from the discharge port surface to the gap forming member is larger than a diameter of the discharge port.   A recording apparatus that has a tank for holding the liquid and performs recording on a print medium using the recording head according to claim 1. In a cross-sectional shape cut through a plane that passes through the center of the discharge port and intersects the discharge port surface and the opening perpendicularly,
The radius of the circle passing through the end portion on the surface side of the gap forming member and the end portion of the discharge port is R0, the pressure acting on the liquid surface in the discharge port is P, and the surface tension of the liquid to be discharged Is γ,
(Γ / P) <R0
The recording apparatus according to claim 7, wherein:   The recording apparatus according to claim 7, further comprising a moisturizing liquid supply unit configured to supply the moisturizing liquid to the gap.   The recording apparatus according to claim 9, wherein the moisturizing liquid supply unit includes a head recovery unit having a cap formed to cover the discharge port and the opening.

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