JP5130100B2 - Liquid ejection head and image forming apparatus - Google Patents

Description

  The present invention relates to a liquid discharge head and an image forming apparatus, and more particularly to a liquid discharge head that discharges droplets by deforming a nozzle plate with heat and an image forming apparatus including the liquid discharge head.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, and a multifunction machine of these, for example, a liquid discharge apparatus including a recording head composed of a liquid discharge head that discharges liquid droplets is used. However, the material is not limited, and a recording medium, a recording medium, a transfer material, a recording paper, and the like are also used synonymously.) Printing, printing, and printing are also used synonymously).

  The image forming apparatus means an apparatus for forming an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, etc. The term “not only” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium. Further, the liquid is not limited to the recording liquid and ink, and is not particularly limited as long as it is a liquid capable of forming an image. Further, the liquid discharge device means a device that discharges liquid from the liquid discharge head.

As described in Patent Document 1, a liquid discharge head used in an image forming apparatus that includes such a liquid discharge apparatus and forms an image includes a nozzle plate with a heater, and a nozzle due to a difference in thermal expansion. One that discharges droplets from a nozzle by deforming a plate is known.
JP 2001-105590 A

In addition, examples of liquid ejection heads that deform a nozzle plate (including a flexible film) by heat include those described in Patent Documents 2 to 4.
Japanese Patent No. 2827544 JP 2002-359981 A JP 2004-160650 A

In addition, regarding the change of the fluid resistance in the present case, as described in Patent Document 5, the bottom surface of the fluid resistance channel portion provided at the side end of the pressure chamber is joined to the diaphragm, There is a bonded piezoelectric element.
JP 2001-063047 A

  Generally, a liquid discharge head is configured to discharge liquid droplets from a nozzle by increasing the pressure in a liquid chamber (flow path) that the nozzle faces. On the other hand, in order to act efficiently, it is desirable that the pressure in the liquid chamber does not escape. Therefore, a fluid resistance portion is provided in the flow path for supplying the liquid into the liquid chamber. In addition, as described in Patent Document 5, there is one that adopts a configuration that increases fluid resistance during droplet ejection.

  However, in the configuration in which the diaphragm that forms the wall surface of the fluid resistance portion is deformed by a piezoelectric element and the fluid resistance value is increased as described in Patent Document 5, there is a problem that the configuration for changing the fluid resistance becomes complicated. .

  The present invention has been made in view of the above problems, and an object of the present invention is to enable efficient droplet discharge by changing the fluid resistance with a simpler configuration.

In order to solve the above-described problem, a liquid discharge head according to claim 1 of the present invention includes:
A nozzle plate on which nozzles for discharging droplets are formed;
And actuator means for deforming by bending in heat peripheral portion of the nozzle of the nozzle plate,
A flow path member that forms a flow path for supplying liquid to the nozzle facing the nozzle plate, and
A fluid resistance path is formed between a peripheral portion of the nozzle of the nozzle plate and an opposing surface of the flow path member facing the peripheral portion;
A recess is formed in a portion facing the nozzle on the facing surface of the flow path member,
The fluid resistance value of the fluid resistance path is higher when the peripheral portion of the nozzle of the nozzle plate is deformed than before the peripheral portion of the nozzle of the nozzle plate is deformed .

  The image forming apparatus according to the present invention includes the liquid discharge head according to the present invention. Here, in the image forming apparatus provided with the actuator means on the nozzle plate, the actuator means can be energized when wiping the ejection surface side of the nozzle plate of the liquid ejection head.

  According to the liquid ejection head according to the present invention, it is possible to perform efficient droplet ejection by changing the fluid resistance with a simple configuration.

  According to the image forming apparatus according to the present invention, since the liquid ejection head according to the present invention is provided, efficient droplet ejection can be performed.

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a first embodiment of a liquid discharge head according to the present invention will be described with reference to FIGS. 1 is a cross-sectional explanatory view of the head along the line AA in FIG. 2, and FIG. 2 is a schematic plan explanatory view of the main part of the head.
This liquid discharge head is configured by joining a nozzle plate 1 and a flow path member (flow path substrate) 2.

  A nozzle 3 for discharging droplets is formed on the nozzle plate 1. This nozzle plate 1 has a three-layer structure. The outer layer 11 is made of a material having a high coefficient of thermal expansion, for example, a layer formed of 16 × 10E-6 / ° C. Ni—Cr, and the inner layer 12 is made of heat. Actuator means which is a layer formed of a material having a small expansion coefficient, for example, Cr of 8 × 10E-6 / ° C., and has a circular planar shape surrounding the periphery of the nozzle 4 as an intermediate layer between these layers 11 and 12 The heater layer 4 is provided and has a bimetal structure. A power supply electrode 5 is connected to the heater layer 4.

  An ink supply port 21 and an ink supply path 22 are formed in the flow path member 2. Further, the flow path member 2 is provided with a convex portion 23 facing the nozzle 3 of the nozzle plate 1 and the peripheral portion (hereinafter referred to as “nozzle peripheral portion”) 6 of the nozzle plate 1. A fluid having a larger fluid resistance (value) than the ink supply port 21 and the ink supply path 22, which are other flow path parts, between the facing surface 24 facing the nozzle peripheral part 6 and the nozzle peripheral part 6 of the nozzle plate 1. A resistance channel 7 is formed.

  In the liquid discharge head configured as described above, liquid (ink) is supplied from the ink supply port 21 as indicated by the white arrow in FIG. 1 and supplied to the fluid resistance path 7 via the ink supply path 22. The nozzle 3 is filled with ink. In this state, when the heater layer 4 is energized (powered), the heat generation of the heater layer 4 heats the nozzle plate 1 having a bimetallic structure. As a result, as shown in FIG. 3, the nozzle peripheral portion 6 of the nozzle plate 1 is bent and deformed in a direction approaching the facing surface 24, the ink in the nozzle 3 is pressurized, and the droplet 30 is discharged from the nozzle 3. Discharged.

  At this time, when the nozzle peripheral portion 6 approaches the facing surface 24 side, the opening cross-sectional area of the fluid resistance path 7 formed between the facing surface 24 and the nozzle peripheral portion 6 becomes small, and the fluid resistance path 7 Therefore, the flow of ink flowing from the nozzle 3 side toward the ink supply path 22 is reduced.

  For this reason, the pressure generated in the nozzle 3 is less likely to be transmitted to the ink supply path 22 and is used exclusively as ink ejection energy, so that the ejection efficiency is greatly improved, and low voltage driving and low power consumption are possible. It becomes.

  In this way, a nozzle plate on which nozzles for discharging droplets are formed, actuator means for deflecting and deforming the peripheral portions of the nozzles of this nozzle plate with heat, and supplying the liquid to the nozzles facing the nozzle plate And a flow resistance member is formed between the peripheral portion of the nozzle of the nozzle plate and the opposing surface of the flow channel member facing the peripheral portion, and the peripheral portion of the nozzle of the nozzle plate By adopting a configuration in which the fluid resistance value of the fluid resistance path changes when the is deformed, it is possible to change the fluid resistance with a simple configuration and perform efficient droplet discharge.

Next, a second embodiment of the liquid ejection head according to the present invention will be described with reference to FIGS. 4 is a cross-sectional explanatory view of the head, and FIG. 5 is a schematic plan explanatory view of the main part of the head.
Here, in the flow path member 2, an ink supply port 21 is disposed on the opposite side of the nozzle 3 and the convex portion 23 of the nozzle plate 1, and ink is supplied from the ink passage 26 to the fluid resistance path 7. As a result, the lateral width of the head is reduced and the cost can be reduced.

Next, a third embodiment of the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 6 is a sectional view of the head.
Here, the fluid resistance path 7 is formed between the nozzle peripheral portion 6 of the nozzle plate 1 and the opposed surface 24 of the flow path member 2, and the opposed surface 24 of the flow path member 2 is connected to the nozzle 3 of the nozzle plate 1. A recess 25 serving as an ink reservoir is formed in the opposite portion. As a result, the ink capacity of the portion facing the nozzle 3 is increased, and sticking due to drying from the nozzle 3 can be largely prevented.

  Here, driving of these liquid discharge heads will be described. As described above, the liquid discharge head discharges droplets by deforming the nozzle peripheral portion 6 by supplying power to the heater layer 4. At this time, by adopting a configuration in which liquid droplets are ejected in a state where the nozzle peripheral portion 6 of the nozzle plate 1 is not in contact with the opposing surface 24, the displacement amount of the nozzle plate 1 (nozzle peripheral portion is determined by the amount of power supplied to the heater layer 4. 6), and the size of the droplets ejected from the nozzle 3 can be made variable. In this way, a multi-valued image can be recorded and high image quality with excellent gradation can be obtained.

  Further, by adopting a configuration in which droplets are ejected while the nozzle peripheral portion 6 of the nozzle plate 1 is in contact with the opposing surface 24, the amount of displacement of the nozzle peripheral portion 6 of the nozzle plate 1 is always constant. Can be stably discharged, and high image quality can be obtained.

  In addition, power is supplied to the heater layer 4 to the extent that ink droplets are not discharged in advance, the size of the fluid resistance path 7 is changed to a predetermined fluid resistance, and then power is supplied to discharge the droplets. It can also be set as the structure discharged. In this way, by changing the magnitude of the fluid resistance in advance and then ejecting the droplet, the size of the droplet can be changed, so that a high image quality with excellent gradation can be obtained.

Next, an example of the image forming apparatus according to the present invention including the liquid discharge head according to the present invention will be described with reference to FIG. FIG. 7 is a schematic configuration diagram of the entire mechanism section of the apparatus.
This image forming apparatus includes an image forming unit 202 and the like inside the apparatus main body 201, and includes a paper feed tray 204 on the lower side of the apparatus main body 201 on which a large number of recording media (sheets) 203 can be stacked. The paper 203 fed from the paper tray 204 is taken in, a required image is recorded by the image forming unit 202 while the paper 203 is transported by the transport mechanism 205, and then a paper discharge tray 206 mounted on the side of the apparatus main body 201. The sheet 203 is discharged.

  In addition, a duplex unit 207 that can be attached to and detached from the apparatus main body 201 is provided, and when performing duplex printing, the sheet 203 is taken into the duplex unit 207 while being transported in the reverse direction by the transport mechanism 205 after one-side (front) printing is completed. Then, the other side (back side) is sent to the transport mechanism 205 again as the printable side, and the sheet 203 is discharged to the discharge tray 206 after the other side (back side) printing is completed.

  Here, the image forming unit 202, for example, ejects liquid droplets of each color of black (K), cyan (C), magenta (M), and yellow (Y), and is a full line type of four liquids according to the present invention. The recording heads 211k, 211c, 211m, and 211y (which are referred to as “recording heads 211” when the colors are not distinguished) are configured by ejection heads, and each recording head 211 has a nozzle surface on which nozzles for ejecting droplets are formed downward. The head holder 213 is attached.

  Further, maintenance recovery mechanisms 212k, 212c, 212m, and 212y for maintaining and recovering the head performance corresponding to each recording head 211 are provided (referred to as “maintenance recovery mechanism 212” when colors are not distinguished), and purge processing, During the head performance maintenance operation such as wiping processing, the recording head 211 and the maintenance / recovery mechanism 212 are relatively moved so that the capping member constituting the maintenance / recovery mechanism 212 faces the nozzle surface of the recording head 211.

  Here, the recording head 211 is arranged to eject droplets of each color in the order of yellow, magenta, cyan, and black from the upstream side in the paper conveyance direction, but the arrangement and the number of colors are not limited to this. Further, as the line type head, one or a plurality of heads provided with a plurality of nozzle rows for discharging droplets of each color at a predetermined interval can be used, and a head and an ink cartridge for supplying ink to the head are integrated. Or a separate body. Furthermore, two heads can be arranged in a straight line at different levels to form a line type head.

  The sheets 203 in the sheet feeding tray 204 are separated one by one by a sheet feeding roller (half-moon roller) 221 and a separation pad (not shown) and fed into the apparatus main body 201, and are registered along the guide surface 223 a of the conveyance guide member 223. 225 and the conveying belt 233, and are sent to the conveying belt 233 of the conveying mechanism 205 via the guide member 226 at a predetermined timing.

  In addition, a guide surface 223 b that guides the sheet 203 sent out from the duplex unit 207 is also formed on the transport guide member 223. Further, a guide member 227 for guiding the sheet 203 returned from the transport mechanism 205 during duplex printing to the duplex unit 207 is also provided.

  The transport mechanism 205 includes an endless transport belt 233 that is stretched between a transport roller 231 that is a driving roller and a driven roller 232, a charging roller 234 that charges the transport belt 233, and an image forming unit 202. A platen member 235 that maintains the flatness of the conveying belt 233 at the opposite portion, a pressing roller 236 that presses the paper 203 fed from the conveying belt 233 against the conveying roller 231, and other recording liquid that is not shown, but adheres to the conveying belt 233. It has a cleaning roller made of a porous material or the like, which is a cleaning means for removing (ink).

  A paper discharge roller 238 and a spur 239 for sending the paper 203 on which an image is recorded to the paper discharge tray 206 are provided on the downstream side of the transport mechanism 205.

  In the image forming apparatus configured as described above, the transport belt 233 rotates in the direction indicated by the arrow, and is positively charged by coming into contact with the charging roller 334 to which a high potential applied voltage is applied. In this case, the charging belt 233 is charged at a predetermined charging pitch by switching the polarity of the charging voltage of the charging roller 234 at a predetermined time interval.

  Here, when the sheet 203 is fed onto the conveying belt 233 charged to this high potential, the inside of the sheet 203 is in a polarized state, and the charge opposite in polarity to the charge on the conveying belt 233 is conveyed to the conveying belt 233 of the sheet 203. The charge on the transport belt 233 and the charge on the transported sheet 203 are electrostatically attracted to each other, and the sheet 203 is electrostatically attracted to the transport belt 233. Is done. In this way, the sheet 203 strongly adsorbed to the conveyor belt 233 is calibrated for warpage and unevenness, and a highly flat surface is formed.

  Then, the paper 203 is moved around the conveyor belt 233 and droplets are ejected from the recording head 211, whereby a required image is formed on the paper 203, and the paper 203 on which the image is recorded is discharged to the paper discharge roller 238. Is discharged to the discharge tray 206.

  As described above, since the image forming apparatus includes the recording head including the liquid discharge head according to the present invention, it is possible to discharge a droplet with high droplet discharge efficiency and form an image at high speed.

Next, an example of the operation of maintaining and recovering the recording head in this image forming apparatus will be described with reference to FIG.
Here, as the maintenance and recovery mechanism 212, a wiping member 251 for wiping the nozzle surface 1a of the recording head 211 is provided on the scanning member 252 that is moved and scanned in the direction of the arrow.
When performing the wiping operation, power is supplied to the heater layer 4 of the recording head 211 so as not to eject droplets to increase the temperature of the surface of the nozzle plate 1, and the wiping member 251 is moved and scanned in this state. The nozzle surface 1a 211 is wiped.

  In this way, the heater layer, which is an actuator, is energized and the temperature of the nozzle plate surface (discharge side surface) rises, so that the adhering ink, resin, etc. are softened and the adhesion force is reduced. The nozzle plate surface can be easily cleaned, the pressing force of the wiping member can be reduced, the wear of the water repellent layer applied to the nozzle surface is reduced, and the durability of the head is improved. Similarly, the nozzle plate can be preheated (heated so as not to eject droplets) to be refilled with ink.

Next, a third embodiment of the liquid ejection head according to the present invention will be described with reference to FIGS. 9 is an explanatory plan view of the main part of the head, and FIG. 10 is an explanatory sectional view of FIG.
This liquid discharge head is a vibration member that is a displacement member that forms a wall surface of a nozzle plate 101 on which a nozzle 111 that discharges droplets is formed and a flow path 112 that supplies liquid to the nozzle 111 in opposition to the nozzle plate 101. A plate member 102, a heater layer 124 that is an actuator means that bends and deforms the diaphragm member 102 by heat, and a nozzle plate of the diaphragm member 102 disposed on the opposite side of the nozzle plate 101 across the diaphragm member 102. A holding member 103 that forms a flow path 113 through which a liquid flows on a surface opposite to the plate 101, a peripheral portion 106 of the nozzle 111 of the nozzle plate 101, and a facing surface of the diaphragm member 102 that faces the peripheral portion 106 A fluid resistance path 107 having a larger fluid resistance than the flow path 112 is formed between the two.

  The diaphragm member 102 has a three-layer structure similar to the nozzle plate 1 of the above-described embodiment, and is opposite to the nozzle plate 101 and a layer 121 made of a material having a relatively low coefficient of thermal expansion on the nozzle plate 101 side. A layer 122 made of a material having a relatively high coefficient of thermal expansion on the side, and a heater layer 124 as an actuator means are provided as an intermediate layer between these layers 121 and 122, and has a bimetallic structure. A power supply electrode 125 is connected to the heater layer 124.

  In the holding member 103, an ink supply port 131 and a flow path 113 are formed. The flow path member 103 is provided with a defining portion 133 that defines the displacement direction of the diaphragm member 102 on the opposite side of the nozzle plate 101 from the nozzle 111. The diaphragm member 102 is provided with a passage 114 that communicates the flow path 113 and the flow path 112.

  In this liquid discharge head configured as described above, liquid (ink) is supplied from the ink supply port 131 and supplied to the fluid resistance path 107 via the flow path 113, the path 114, and the flow path 112. Ink is filled. In this state, when the heater layer 124 of the diaphragm member 102 is energized (powered), the diaphragm member 102 having a bimetallic structure is heated by the heat generated by the heater layer 124. As a result, the central portion of the vibration plate member 102 is deformed toward the nozzle 111 of the nozzle plate 101, the ink in the nozzle 111 is pressurized, and droplets are ejected from the nozzle 111.

  At this time, since the diaphragm member 102 bends in a direction approaching the nozzle peripheral portion 106, the opening cross-sectional area of the fluid resistance path 107 is reduced, and the fluid resistance value of the fluid resistance path 107 is increased. Since the flow of ink flowing toward the flow path 112 is reduced and used exclusively as ink discharge energy, the discharge efficiency is greatly improved, and low voltage driving and low power consumption are possible.

  Since the vibration plate member 102 including the heater layer 124 serving as the actuator means is disposed in the liquid, heat transfer from the heater layer 124 is not stored in the holding member 103, the nozzle plate 101, etc., and stable. Can be continuously driven.

Next, a fourth embodiment of the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 11 is a cross-sectional explanatory view of the main part of the head.
This liquid discharge head has substantially the same configuration as that of the third embodiment, but the nozzle plate 101 and the vibration plate 102 form a liquid chamber 142 where the nozzle 111 faces, and the passage of the vibration plate member 102 passes through the fluid resistance portion. By setting the pressure to 107, the ink in the liquid chamber 142 is pressurized by the displacement of the vibration plate member 102 due to heat, and the droplets are ejected from the nozzle 111.

  Also in this configuration, since the vibration plate member 102 including the heater layer 124 is disposed in the ink that is liquid, heat transfer from the heater layer 124 is not stored in the holding member 103 and the nozzle plate 101, so that it is stably performed. Continuous driving can be performed.

Next, a fifth embodiment of the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 12 is an explanatory cross-sectional view of the main part of the head.
The liquid discharge head includes a flow path member 300, a nozzle plate 301 on which a nozzle 311 for discharging droplets is formed, a pressure chamber 312 that faces the nozzle plate 301 and communicates with the nozzle 311 and a liquid in the pressure chamber 312. A diaphragm member 302 that is a displacement member that forms a wall surface of the flow path 313 that supplies the fluid, a heater layer 304 that is an actuator means that deforms the diaphragm member 302 by, for example, heat, and the diaphragm member 302 are sandwiched therebetween. And a stopper member 305 that is disposed on the opposite side of the nozzle plate 301 (pressure chamber 312) and that the diaphragm member 302 contacts when the diaphragm member 302 is displaced by the actuator means.

  Further, the convex portion 306 is formed around the nozzle 311 of the nozzle plate 301 to form the pressure chamber 312, and between the convex portion 306 and the facing surface of the vibration plate member 302 facing the convex portion 306, A fluid resistance path 307 having a larger fluid resistance than the flow path 313 communicating the pressure chamber 312 and the flow path 313 is formed. The liquid supply to the flow path 313 is performed by a supply port (not shown).

  As shown in FIG. 13, the diaphragm member 302 includes a diaphragm layer 321 made of, for example, a polysilicon layer, a heater layer 304, an insulating layer 322, a contact-resistant (ink-resistant) layer 323, and the like. In the initial state, initial bending is applied to the liquid-resistant layer 323 side. In this case, since the periphery of the diaphragm member 302 is fixed, the central portion (portion facing the nozzle 311) bends toward the stopper member 305.

  Here, when the heater layer 304 of the diaphragm member 302 is energized, the heater member 304 expands in the surface direction, and the diaphragm member 302 is given an initial deflection toward the liquid contact resistant layer 323, so that FIG. As shown in FIG. 14B, the nozzle member 311 is displaced toward the stopper member 305 and comes into contact with the stopper member 305. As the diaphragm member 302 is further expanded, the periphery is fixed. The liquid is displaced toward the side to pressurize the liquid in the pressure chamber 312, whereby a droplet is discharged from the nozzle 311.

  At this time, the diaphragm member 302 bends in a direction approaching the convex portion 306 around the nozzle, whereby the opening cross-sectional area of the fluid resistance path 307 is reduced and the fluid resistance value of the fluid resistance path 307 is increased. Since the flow of ink flowing from the 311 side toward the pressure chamber 312 is reduced and it is used exclusively as ink ejection energy, the ejection efficiency is greatly improved, and low voltage driving and low power consumption are possible. .

Here, an example of the manufacturing process of the diaphragm member 302 described above will be described with reference to FIG.
First, as shown in FIG. 15A, a silicon nitride film (Si ₃ N ₄ ) 402 is formed to a thickness of 0.2 μm by LPCVD on a silicon substrate 401, and then silicon silicon is used as shown in FIG. 15B. A metal film (heater layer) 403 is formed to a thickness of 0.2 μm on the nitride film 402 by sputtering, and patterned into a predetermined shape by lithoetch, and further on the metal film 403 as shown in FIG. A polysilicon layer 404 is formed to a thickness of 0.5 μm by LPCVD, and then a silicon oxide film 405 is formed to a thickness of 0.2 μm on the polysilicon layer 404 by LPCVD as shown in FIG. Thereafter, as shown in FIG. 5E, the silicon substrate 401 is etched to form the pressure chambers 312 and the recesses 406 that become the flow paths 313.

  In this case, since the silicon nitride film 402 and the metal film 403 are tensile stress films, and the polysilicon layer 404 and the silicon oxide film 405 are compressive stress films, the vibration plate member 302 is bent toward the silicon oxide film 405 as a whole. Become a shape.

Next, a sixth embodiment of the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 16 is an explanatory cross-sectional view of the main part of the head.
Here, in the liquid ejection head having the configuration of the fifth embodiment, the pressure between the peripheral portion of the nozzle 311 of the nozzle plate 301 and the facing surface of the vibration plate member 302 facing the peripheral portion on the vibration plate member 302 side. A convex portion 306 is formed which forms a fluid resistance path 307 having a larger fluid resistance than the flow path 313 communicating the chamber 312 and the flow path 313.

  In this case, when the heater layer 304 of the diaphragm member 302 is energized, the diaphragm member 302 is displaced as shown in FIG.

Next, a seventh embodiment of the liquid ejection head according to the present invention will be described with reference to FIG. FIG. 18 is an explanatory cross-sectional view of the main part of the head.
Here, in the liquid discharge head having the configuration of the sixth embodiment, the stopper member 305 is disposed between the central portion and the outer peripheral portion of the diaphragm member 302. Even with this configuration, as in the fifth and sixth embodiments, the diaphragm member 302 abuts against the stopper members 305 and 305 and then is displaced toward the nozzle 311 side to eject droplets.

  The liquid discharge heads of these third to seventh embodiments can be mounted on the image forming apparatus described above.

  The image forming apparatus according to the present invention can be applied to a facsimile machine, a copying machine, a printer / fax / copier multifunction machine, etc., in addition to an inkjet printer. Furthermore, the present invention can also be applied to an image forming apparatus that discharges a liquid (recording liquid) other than ink, such as a resist or a DNA sample in the medical field.

FIG. 3 is a cross-sectional explanatory view of the head taken along the line AA of FIG. 2 showing the first embodiment of the liquid discharge head according to the present invention. FIG. 3 is a schematic plan view illustrating a main part of the head. It is sectional explanatory drawing with which it uses for operation | movement description of the head. FIG. 5 is a cross-sectional explanatory view of the head showing a second embodiment of the liquid ejection head according to the present invention. FIG. 3 is a schematic plan view illustrating a main part of the head. FIG. 5 is a cross-sectional explanatory view of the head showing a second embodiment of the liquid ejection head according to the present invention. 1 is a schematic explanatory diagram illustrating an example of an image forming apparatus according to the present invention. It is explanatory drawing with which it uses for description of the wiping operation | movement in the apparatus. FIG. 6 is a plan view of relevant parts showing a third embodiment of a liquid ejection head according to the present invention. Similarly it is principal part cross-sectional explanatory drawing. FIG. 10 is a cross-sectional explanatory view of a main part showing a fourth embodiment of a liquid ejection head according to the present invention. FIG. 10 is a cross-sectional explanatory view of a main part showing a fourth embodiment of a liquid ejection head according to the present invention. It is sectional explanatory drawing which shows an example of the diaphragm member of the head. It is sectional explanatory drawing with which it uses for description of an effect | action of the head. It is sectional explanatory drawing with which it uses for description of an example of the manufacturing process of the diaphragm member of the head. FIG. 10 is an explanatory cross-sectional view of a relevant part showing a fifth embodiment of a liquid ejection head according to the present invention. It is sectional explanatory drawing with which it uses for description of an effect | action of the head. It is principal part cross-section explanatory drawing which shows 6th Embodiment of the liquid discharge head which concerns on this invention.

Explanation of symbols

1 ... Nozzle plate (nozzle member)
2 ... Channel member 3 ... Nozzle 4 ... Heater layer (actuator means)
6 ... Nozzle peripheral part 7 ... Fluid resistance path 23 ... Convex part 24 ... Opposing surface 25 ... Concave part 101 ... Nozzle plate 102 ... Diaphragm member (displacement member)
103 ... Holding member 124 ... Heater layer (actuator means)
211k, 211c, 211m, 211y ... recording head 212k, 212c, 212m, 212y ... maintenance / recovery mechanism 301 ... nozzle plate 302 ... diaphragm member (displacement member)
304 ... Heater layer 305 ... Stopper member 307 ... Fluid resistance path 308 ... Projection 311 ... Nozzle 312 ... Pressure chamber 313 ... Flow path

Claims (6)

A nozzle plate on which nozzles for discharging droplets are formed;
And actuator means for deforming by bending in heat peripheral portion of the nozzle of the nozzle plate,
A flow path member that forms a flow path for supplying liquid to the nozzle facing the nozzle plate, and
A fluid resistance path is formed between a peripheral portion of the nozzle of the nozzle plate and an opposing surface of the flow path member facing the peripheral portion;
A recess is formed in a portion facing the nozzle on the facing surface of the flow path member,
The liquid, wherein when the peripheral portion of the nozzle of the nozzle plate is deformed, the fluid resistance value of the fluid resistance path is higher than before the peripheral portion of the nozzle of the nozzle plate is deformed. Discharge head.   2. The liquid ejection head according to claim 1, wherein the flow path member has a convex portion in a portion facing the nozzle and a peripheral portion of the nozzle, and a surface of the convex portion facing the nozzle plate and the nozzle plate A liquid discharge head, wherein the fluid resistance path is formed with a peripheral portion of the nozzle.   The liquid discharge head according to claim 2, wherein the flow path member has a supply port for supplying the liquid on a side opposite to the nozzles of the nozzle plate with the convex portion interposed therebetween. head. A nozzle plate on which nozzles for discharging droplets are formed;
Actuator means for deforming the nozzle plate by deflecting the peripheral portion of the nozzle with heat;
A flow path member that forms a flow path for supplying liquid to the nozzle facing the nozzle plate, and
A fluid resistance path is formed between a peripheral portion of the nozzle of the nozzle plate and an opposing surface of the flow path member facing the peripheral portion;
When the peripheral portion of the nozzle of the nozzle plate is deformed, the fluid resistance value of the fluid resistance path is higher than before the peripheral portion of the nozzle of the nozzle plate is deformed,
The flow path member has a convex portion at a portion facing the nozzle and a peripheral portion of the nozzle,
The fluid resistance path is formed between a surface of the convex portion facing the nozzle plate and a peripheral portion of the nozzle of the nozzle plate,
The liquid discharge head according to claim 1, wherein a supply port for supplying the liquid is disposed on the side of the flow path member opposite to the nozzle of the nozzle plate with the convex portion interposed therebetween. In the image forming apparatus that forms an image by ejecting droplets from a liquid ejecting head, an image forming apparatus characterized by comprising a liquid discharge head according to any one of claims 1 to 4. In the image forming apparatus that forms an image by ejecting droplets from a liquid discharge head provided with a liquid discharge head according to any one of claims 1 to 4, wipes the ejection surface of the nozzle plate of the liquid ejection head An image forming apparatus characterized in that the actuator means is sometimes energized.

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