Abstract: The invention relates to a method of fabricating an ink jet nozzle. The method includes the steps of depositing and etching a passivation layer on a silicon substrate having drive circuitry and an interlayer dielectric interconnect to form a first sacrificial scaffold. Also included are the steps of depositing heater material over the first sacrificial scaffold and etching said heater material to define a heater element, and depositing and developing a layer of photoresist to define a second sacrificial scaffold defining sidewalls for a nozzle chamber. The method also includes the steps of depositing silicon nitride onto the second sacrificial scaffold to form a roof over the nozzle chamber, and etching a nozzle aperture through the roof down to the second sacrificial scaffold.

Abstract: A method of producing substrate 3 having feedthrough electrodes for an inkjet head, including: a step of forming grooves in the substrate 1 in the same pitch as that of the inkjet head; a step of setting conductive member 101 in the grooves; a step of adhering covering substrate 2 onto substrate 1; a step of cutting adhered substrate 1 and covering substrate 2 in a direction perpendicular to that of the grooves in a predetermined width.

Abstract: There is provided a method of manufacturing an inkjet print head. The method includes providing a head portion having a dummy portion disposed on a surface of a pressure area pressurizing an ink chamber, a nozzle connected to the ink chamber for ink ejection and the ink chamber for ink supply to the nozzle, and removing the dummy portion. The method allows for the improvement of ink ejection and nozzle density. Also, the method allows for the forming of a thin-type head portion using the dummy portion.

Abstract: A fluid ejection device includes a plurality of address lines and a fire line for communicating a fire signal. The device also includes a plurality of nozzle circuits coupled to the fire line and the plurality of address lines. Each nozzle circuit is configured, when enabled, to eject fluid via a different one of a plurality of nozzles in response to the fire signal. A subset of the plurality of address lines is coupled to each pair of the plurality of nozzle circuits. Each subset that is coupled to one of the pairs of nozzle circuits is selected so that simultaneous activation of every address line of that subset simultaneously enables each nozzle circuit in the pair or pairs of nozzle circuits coupled to that triad and none of the other nozzle circuits of the plurality of nozzle circuits.

Abstract: A method for manufacturing an ink cartridge includes the step of connecting a film or a pair of films to a frame. The films and the frame define an ink chamber therein, and the ink cartridge includes the films and the frame. The method also includes the step of positioning a patterned member adjacent to the films. The patterned member includes a first pattern, and the first pattern includes a first portion and a second portion which is raised with respect to the first portion. Moreover, the method includes the step of forming a second pattern corresponding to the first pattern on the films by generating a pressure differential between a pressure inside the ink chamber and a pressure outside the ink chamber, in which the pressure differential draws the films into contact with the first pattern.

Abstract: A flow path regulating member for regulating an ink flow path leading into the channels is formed on the rear side of the head chip by exposure and development through lamination of the photo masks having an opening of a predetermined pattern, after a photosensitive resin film has been bonded on the rear side of the head chip by heat and pressure without using an adhesive; this head chip being characterized in that the channels, and drive walls made up of piezoelectric elements are arranged alternately, the apertures of the channels are arranged on the front side and rear side, respectively, and drive electrodes are formed in channels.

Abstract: Provided are a droplet-ejecting head having good displacement and a droplet-ejecting apparatus. The droplet-ejecting head includes a pressure chamber; a piezoelectric element which includes a first electrode, a second electrode, and a piezoelectric layer disposed between the first electrode and the second electrode, the piezoelectric layer being made of a lead zirconate titanate; and a nozzle plate having a nozzle orifice communicating with the pressure chamber. The first electrode includes at least one lanthanum nickelate layer which is located on the piezoelectric layer side. The piezoelectric layer has a distribution in which the concentration of lanthanum and nickel decrease from the interface between the lanthanum nickelate layer and the piezoelectric layer toward the second electrode. Lanthanum is locally distributed in the piezoelectric layer. Nickel is globally distributed in the piezoelectric layer so as to have a plurality of peaks. At least one of the peaks is split.

Abstract: A fluid ejection device includes a circuit layer having a fluid outlet on a lower surface, a chamber substrate having a fluid inlet on an upper surface, an electrical contact electrically connecting the chamber substrate to the lower surface of the circuit layer, and a seal forming a fluid connection between the fluid outlet of the circuit layer and the fluid inlet of the chamber substrate. The seal and the electrical contact are a eutectic material. The seal and the electrical contact may be the same material.

Abstract: There is provided a method for manufacturing an ink jet recording head in which a plurality of recording element substrates used for discharging ink are appropriately arranged onto a support substrate.

Abstract: The present invention relates to a bonding device for bonding a flexible printed circuit board (PCB) to a printhead assembly. The printhead assembly includes a printhead carrier and an ink ejection printhead carried by the carrier. The bonding device includes a support structure assembly and a first heater assembly arranged on the support structure assembly to be movable along a first path and configured to bond the flexible PCB to the printhead. A bending mechanism is arranged on the support structure and is configured to bend the bonded PCB. A second heater assembly is arranged on the support structure assembly to be movable along a second path and is configured to bond the bent PCB to the printhead carrier. A control system controls operation of the heater assemblies and the bending mechanism.

Abstract: A method of calibrating a temperature sensor, provided in the recording head, for measuring a temperature of a liquid in a recording head of an inkjet type having nozzles from which the liquid is ejected, includes: an ambient temperature acquisition step of acquiring an ambient temperature where the recording head is located; a sensor output value acquisition step of acquiring an output value of the temperature sensor in a state where the liquid has been filled into the recording head; a calculation step of calculating a correction coefficient for correcting the output value according to the ambient temperature and the output value; and a storage step of storing the correction coefficient in a storage device of the recording head.

Abstract: A substrate processing apparatus includes a process chamber having a chamber lid and a chamber body to provide a reaction space and a gas distributing means including a plate and an injection part in the process chamber. The injection part includes a plurality of through holes in the plate and a discharge portion capable of being in fluid communication with the plurality of through holes. The discharge portion has a matrix shape and provides a space where a plasma is discharged. The apparatus additionally includes a susceptor in the process chamber. The susceptor faces the gas distributing means.

Abstract: A method of manufacturing an orientation film which method is suitable for manufacturing an orientation film containing a ceramic at low cost. The method includes the steps of: (a) forming a film containing a piezoelectric ceramic on a seed substrate in which crystal orientation is controlled at least on a surface thereof by using an aerosol deposition method of injecting powder toward a substrate and depositing the powder on the substrate; and (b) heat-treating the ceramic film formed at step (a) to form an orientation film in which crystal grains contained in the ceramic film is oriented.

Abstract: The ink jet cartridge includes a tank case that has a space having a opening, a lid that closes the opening, an ink accommodating section that is formed with the space of the tank case and the lid, and an ink absorber that is accommodated in the ink accommodating section. Also, an atmosphere communication port that passes through the lid and a projection section that projects to the space of the tank case are provided in the lid. The ink absorber consists of a fiber aggregate, and a welding section in which the fibers are combined to each other and an unwelded section in which the fibers are not combined to each other are provided on a surface that faces the lid.

Abstract: A method of producing a pagewidth inkjet printhead includes forming a substrate having defined therein a nozzle chamber operable to receive and store a fluid, the chamber fed at one side by an inlet passage; forming a nozzle plate in-situ on the substrate to define a nozzle opening on an opposite side of the nozzle chamber to the inlet passage; and forming a heater element including an electrically conductive element between the nozzle opening and the inlet passage, the heater element formed such that the electrically conductive element is in direct contact with the fluid in the nozzle chamber. The heater element is cantilever supported at one end by the nozzle chamber. The electrically conductive element includes two major face, a first major face facing the nozzle opening, and a second major face facing the inlet passage, the first and second major faces both in direct contact with the fluid in the nozzle chamber.

Abstract: A frame and an ink-jet head including a nozzle plate and a fixed plate are placed on a first jig having a first face and a second face parallel to the first face and located outside the first face when seen in a direction perpendicular to the first face while being at a predetermined distance from the first face with respect to the direction perpendicular to the first face, in such a manner that a portion of the frame other than a portion formed with an adhesive layer is in contact with the second face, that an ink ejection face of the nozzle plate is opposed to the first face, and that both ends of the fixed plate are in contact with the adhesive layer. Thereafter, the adhesive layer is cured under a state where the ink ejection face is in contact with the first face, so that a head unit is manufactured.

Abstract: In a production method of a piezoelectric element, an unneeded electric field is prevented from being applied to a piezoelectric thin film layer during the production process, resulting in a high performance piezoelectric element production method. The production method includes a first process for depositing an under electrode layer, a piezoelectric thin film layer and an upper electrode layer successively on a substrate such that the under electrode layer and the upper electrode layer form a short-circuit, a second process, after the first process, for etching including dry etching, the second process commenced while the under electrode layer and the upper electrode layer are short-circuited, a third process, after the second process, for polarizing by applying a voltage across the under electrode layer and the upper electrode layer, a fourth process, after the third process, for individualizing each piezoelectric element.

Abstract: A method for making an electromechanical device including forming an electromechanical transducer that includes a deposited metallic diaphragm, and attaching the electromechanical transducer to a fluid channel substructure.

Abstract: Fire protection apparatus, systems, and methods for addressing a fire with a mist are provided. More particularly, the invention provides systems and their method of design which provide a water mist to address and preferably suppress a fire. The invention further provides systems and methods for total flooding volume protection of a space to address a fire, preferably control, suppress, and more preferably extinguish a fire. The invention further provides atomizing devices for use in such systems and methods.

Abstract: A method of manufacturing actuators for an inkjet head includes the step of measuring an absolute value of a coercive voltage of an active layer. The method further includes the step of sorting the actuators based at least on the coercive voltage. Each of the actuators includes a first electrode, a second electrode, an active layer positioned between the first electrode and the second electrode, and an inactive layer wherein the second electrode is positioned between the inactive layer and the active layer.

Abstract: A method of producing an ink jet printhead includes steps of forming a substrate having defined therein a nozzle chamber for receiving and storing a fluid, the chamber fed at one side by an inlet passage; forming a nozzle plate in-situ on the substrate to define a nozzle opening on an opposite side of the nozzle chamber to the inlet passage; forming first and second heater elements suspended between the nozzle opening and the inlet passage, the heater elements each having two opposite planar sides and each positioned to be in direct thermal contact with the fluid stored in the nozzle chamber at both opposed planar sides; connecting the first heater element to a first drive circuit; and connecting the second heater element to a second drive circuit separate from the first drive circuit. The first heater element is formed on a different layer to the second heater element, and the first heater element is formed with a surface area larger than that the second heater element.

Abstract: An inter-terminal connection structure includes: a first terminal; a second terminal which is separated from the first terminal; a first connection member which is in contact with the first terminal; a second connection member which includes a coil portion, a first arm portion extending from one end of the coil portion to be in contact with the second terminal, a second arm portion extending from the other end of the coil portion to be in contact with the first connection member; a container main body which has a bottom face and a side face on which the second terminal is mounted; and a positioning member which includes a first protruding portion to be inserted into the coil portion of the second connection member, and a second protruding portion which determines a relative angle between the first and second arm portions.

Abstract: A method for manufacturing a liquid jet head is provided, which includes: a preparation step of preparing a substrate array which is provided with a first substrate having formed therein a first flow path, a second substrate bonded to one side of the first substrate and having formed therein a second flow path, and a separation layer partitioning the first flow path and the second flow path; a sealing step of sealing the first flow path by adhering a sealing film onto a side of the first substrate opposite to the second substrate using an adhesive layer; and a removal step of removing the separation layer after the sealing step is performed, wherein in the removal step, the separation layer is removed in a state in which an internal pressure of the first flow path is lower than an external pressure.

Abstract: An actuator that includes a substrate; first conductive layers provided so as to extend in a first direction and to be disposed adjacent to each other on the substrate; a piezoelectric body layer having a first portion formed so as to cover the first conductive layers and openings between the first conductive layers, a second portion other than the first portions, and a contact to the first conductive layer; a second conductive layer having a third portion which overlap with the first conductive layers in the second direction, a fourth portion connected to the third portion being formed over the second portion of the piezoelectric body layer, and a fifth portion connected to the first conductive layer in the contact ; and a wiring having a sixth portion which is formed over the fourth portion of the second conductive layer and a seventh portion connected to the fifth portion.

Abstract: A fluid ejection device ejecting a fluid, the fluid ejection device includes: a fluid ejection unit; a main chassis case; a fluid-containing pack; a container case; and a plurality of holders. The fluid ejection unit ejects a fluid onto an ejection target. The main chassis case houses the fluid ejection unit. The fluid-containing pack contains a fluid for ejection. The container case houses the fluid-containing pack. The plurality of holders is disposed inside the container case. Each of a plurality of holders includes an incline panel that inclines toward the inside base plane, and the fluid-containing pack rests on the incline panel.

Abstract: A plurality of liquid ejection heads is attached to a head attachment member. The head attachment member is disposed so as to face a support drum for supporting an ejection-receiving medium and rotating about a shaft. The head attachment member includes a pair of plate-shaped members each having an attachment surface to which a plurality of head groups each including the liquid ejection heads is attached and a back surface extending parallel to the attachment surface. End parts of the plate-shaped members are connected to each other so as to be able to rotate about a hinge part so that an angle formed by the attachment surfaces is adjustable.

Abstract: There is provided an inkjet print head including: a body portion including a nozzle ejecting ink, an ink chamber connected to the nozzle so as to supply the ink to the nozzle, and a vibration plate transferring vibrations to the ink chamber and formed of an elastomer; an actuator mounted on the body portion in order to be arranged to correspond to the ink chamber and generating the vibrations transferred to the ink chamber; and a buffer layer allowing for an electrical connection with the actuator and having a Young's modulus greater than that of the body portion.

Abstract: In a method of manufacturing an ink-jet recording head including plural recording element substrates having at least one nozzle array comprising nozzles to eject ink, an electric wiring member supplying signals to the recording element substrates, a member supporting the recording element substrates and the electric wiring member, electric connecting portions electrically interconnecting the recording element substrates and the electric wiring member, and a sealant sealing the electric connecting portions, the method comprises the steps of applying sealants to the supporting member including the recording element substrates, the electric wiring member, and the electric connecting portions, and curing the sealants, measuring a distance between reference positions set on each recording element substrate before and after the curing of the sealants, and mounting the recording element substrates to the supporting member depending on a difference in the distance between the reference positions measured before and a

Abstract: A wafer assembly comprises a wafer having a MEMS layer formed on a frontside and a polymer coating covering the MEMS layer. A holding means is releasably attached to the polymer coating so that the wafer assembly facilitates performance of backside operations on a backside of the wafer. The polymer coating is comprised of a polymerized siloxane.

Abstract: A method of manufacturing a fluid ejection device includes providing a barrier layer and an orifice layer on a substrate, laminating a layer of photo-resist over a substantially planar surface of the orifice layer, forming an orifice in the orifice layer, and forming a counterbore in the layer of photo-resist, with forming a counterbore in the layer of photo-resist including exposing a portion of the substantially planar surface of the orifice layer within the counterbore.

Abstract: There is disclosed a manufacturing method of a liquid discharge head including a substrate in which a first energy generating element and a second energy generating element that generate energy used for discharging liquid are provided, a discharge port member in which a first discharge port discharging the liquid is provided corresponding to the first energy generating element and a second discharge port discharging the liquid is provided corresponding to the second energy generating element, and a flow path wall member having a portion of the liquid flow path wall that communicates with the first discharge port and the second discharge port, in which a distance between the second energy generating element and the second discharge port is larger than that between the first energy generating element and the first discharge port.

Abstract: A method for manufacturing a piezoelectric element comprising forming a titanium film containing titanium; forming a platinum film containing platinum on the titanium film; forming a piezoelectric precursor film containing bismuth, lanthanum, iron and manganese on the platinum film; crystallizing the piezoelectric precursor film to form a piezoelectric layer by firing the piezoelectric precursor film in an atmosphere of an inert gas; and forming an electrode on the piezoelectric layer.

Abstract: A flow path forming member is formed with a recessed portion for forming an ink flow path. A junction surface of the flow path forming member is in a protruded state from a non-junction surface. The flow path forming member is composed of a transparent resin exhibiting transmissivity of laser beam. A tank holder is composed of a non-transmissive resin having no transmissivity of the laser beam. In a state where the flow path forming member is press-connected to the tank holder, the junction surface is welded by irradiating a periphery of the ink flow path with the laser beam from the side of the flow path forming member, thereby forming an ink flow path. Provided is an ink jet recording head in which the tank holder and the flow path forming member that serve to form the ink flow path are surely connected by a small number of steps without producing foreign matters within the ink flow path.

Abstract: The described embodiments relate to methods and systems of forming slots in a substrate. One exemplary embodiment forms a feature into a substrate having a first substrate surface and a second substrate surface, and moves a sand drill nozzle along the substrate to remove substrate material sufficient to form, in combination with said forming, a slot through the substrate.

Abstract: A method forms apertures in a polymer aperture plate configured for use in a piezoelectric print head. The method includes bonding a polymer aperture plate to an outlet plate configured with outlets, and aligning a laser with the outlets in the outlet plate to ablate apertures in the polymer aperture plate that are aligned with the outlets.

Abstract: A fluid ejection apparatus includes a substrate having a plurality of fluid passages for fluid flow and a plurality of nozzles fluidically connected to the fluid passages, a plurality of actuators positioned on top of the substrate to cause fluid in the plurality of fluid passages to be ejected from the plurality of nozzles, a housing component with a descending portion that projects down to the substrate, an integrated circuit chip supported on the substrate, a potting barrier secured to the housing component and positioned between the integrated circuit chip and the actuators, and a potting material between the integrated circuit chip and the barrier.

Abstract: One of an electric wiring substrate and a retaining member includes a section having an absorptance with respect to a laser beam, and the other one of the electric wiring substrate and the retaining member includes a section having a transmittance with respect to the laser beam. The electric wiring substrate and the retaining member are welded to each other by irradiation with a laser beam. At this time, the electric wiring substrate and the retaining member are welded to each other at least at a part of an outer peripheral section of the electric wiring substrate.

Abstract: A system and method for lowering the structural natural frequency of a synthetic jet actuator is disclosed. A synthetic jet actuator is provided that includes a first plate, a second plate spaced apart from the first plate and arranged parallelly thereto, and a spacer element configured to space the first plate apart from the second plate and define a chamber along with the first and second plates. The spacer element includes at least one orifice formed therein such that the chamber is in fluid communication with an environment external to the chamber, and the spacer element is constructed to deform in a bending motion in response to a deflection of at least one of the first and second plates.

Abstract: A recording head includes a substrate whose first surface has an element that generates energy used for ejecting liquid; a first portion that supports a second surface of the substrate; a wiring member having multiple electrode leads connected to multiple electrode pads provided in the substrate; a second portion that supports the wiring member; and a sealant that seals a section including a connection section between the electrode pads and the electrode leads. A region surrounded by the substrate, the second portion, and the electrode leads is provided with an ascending portion that increases in height in a direction extending from the second surface toward the first surface, the ascending portion increasing in height from a first end to a second end of the region in an arrayed direction of the electrode leads.

Abstract: A fuel injector, which has a valve-seat body with a fixed valve-seat surface, a valve-closure member cooperating with the valve seat for the opening and closing of the valve. The valve-seat body is accommodated in a longitudinal opening of a valve-seat support and fixedly joined thereto. An atomizer front piece is galvanically premolded directly on a lower end face of the valve-seat body in an adhesive manner. At least one spray-discharge orifice is provided in the atomizer front piece, which preferably widens in a funnel shape in the downstream direction. The fuel injector is particularly suitable for use in fuel-injection systems of mixture-compressing internal combustion engines having externally supplied ignition.

Abstract: A manifold assembly has been constructed that filters ink before the ink enters an inkjet ejector in an inkjet print head. The manifold assembly includes an adhesive layer having openings, an ink manifold layer having a plurality of openings, the openings in the adhesive layer being aligned with the openings in the ink manifold layer, and a polymer layer having a plurality of filter areas, the filter areas being aligned with the openings in the ink manifold layer and the openings in the adhesive layer, the adhesive layer being interposed between the polymer layer and the ink manifold layer.

Abstract: A method of manufacturing a liquid ejecting head that ejects a liquid supplied from a liquid storing member through a liquid supply path. The method includes positioning a filter to a first or second supply member by using positioning pins upon disposing the filter between first and second liquid supply paths. The first supply member has the first liquid supply path. The second supply member has the second liquid supply path on the side of one surface of the first supply member to communicate with the first liquid supply path. At least the first supply member and the second supply member are integrated such that a fixed portion is molded by injecting a resin material from an injection portion of a mold at a position where the first and second liquid supply paths are interposed between the positioning pins.

Abstract: A printhead may include a flow channel unit configured to discharge liquid. The printhead may include an actuator unit configured to apply discharge energy to the liquid in the flow channel unit. The printhead may include a flat flexible substrate connected to the actuator unit and configured to supply a drive signal to the actuator unit. The printhead may include a plurality of contact points disposed in an outline of the actuator unit in plan view and configured to electrically connect the actuator unit and the flat flexible substrate. The printhead may include a reinforcing member configured to fix a reinforcing portion, which includes at least part of an outer periphery of the actuator unit and the flat flexible substrate.

Abstract: An ink jet head circuit board is provided which has heaters to generate thermal energy for ink ejection as they are energized. This circuit board has the heaters formed with high precision to reduce their areas. It also has provisions to protect the electrode wires against corrosion and prevent a progress of corrosion. The substrate is deposited with the thin first electrodes made of a corrosion resistant metal. This is further deposited with the resistor layer. The second electrodes made of aluminum are deposited to overlap the first electrodes to form the heater without causing large dimensional variations among the heaters. With this construction, if a defect should occur in a protective layer on or near the heater, a progress of corrosion can effectively be prevented because the material of the resistor layer is more resistant to encroachment than aluminum and the first electrodes are corrosion resistant.

Abstract: A printed circuit board manufacturing method includes: a hole-forming step of forming a through hole in a substrate that will become an element of a printed circuit board after manufacturing; and a jig insertion step of inserting a jig in the through hole formed in the hole-forming step such that the jig adheres to a portion of an inner wall of the through hole, the inner wall having a portion connecting to the outside of the through hole. The method further includes a conductive-film forming step of forming a conductive film only on the portion of the inner wall of the through hole connecting to the outside of the through hole, after the jig is inserted into the through hole in the jig insertion step.

Abstract: The present invention discloses a package method of the inkjet-printhead chip and its structure. The structure includes: a nozzle structure of a print element including an ink chamber layer and a nozzle layer on the ink chamber layer, wherein a plurality of nozzle through holes are set in the nozzle layer and pass through an ink chamber of the ink chamber layer; a flexible substrate set on the nozzle layer, wherein there is at least an opening set in the flexible substrate to expose those nozzle through holes; and a chip set under the ink chamber layer. Besides, the present package method is to utilize the micro-manufacturing process to form the nozzle structure of a print element and the tape automatic bonding process to bond the flexible substrate on the nozzle layer and the chip under the ink chamber layer.

Abstract: There is disclosed a manufacturing method in which depths of individual liquid chambers can be set to be small. The manufacturing method is a manufacturing method of a liquid discharge head having a liquid chamber which communicates with a discharge port for discharging a liquid, and includes: etching a first Si layer of an SOI substrate by use of an insulating layer as an etching stop layer to form the liquid chamber at the first Si layer, the SOI substrate being constituted by the first Si layer, the insulating layer and a second Si layer in this order; and removing a part or all of the second Si layer.

Abstract: Disclosed is a method of manufacturing an inkjet head discharging ink. The method in accordance with an embodiment of the present invention can include: heating the inkjet head to a temperature over a melting point of a filler; filling the inkjet head with the filler such that a gap inside the inkjet head is filled with the filler; and discharging the filler out of the inkjet head such that the filler in the gap of the inkjet head remains.

Abstract: An ink manifold for supplying liquid ink to a heater chip of an inkjet printhead. Ink ports on one side of the manifold feed liquid ink to the ink channels on the other side of the manifold, and thus to the backside ink trenches of the heater chip. The placement and number of ink ports formed in the ink manifold are optimized so that when the heater chip and the ink manifold are scaled down in size, the ink carrying capacity of the printhead components is not compromised. Similarly, when the ink manifold is scaled down, the optimization process allows the seal width between the ink port features of the manifold to be maintained above a specified minimum.

Abstract: A method of producing an ink jet printhead includes steps of forming a substrate having defined therein a nozzle chamber for receiving and storing a fluid, the chamber fed at one side by an inlet passage; forming a nozzle plate in-situ on the substrate to define a nozzle opening on an opposite side of the nozzle chamber to the inlet passage; and forming first and second heater elements suspended between the nozzle opening and the inlet passage, the heater elements having two opposite planar sides and positioned to be in direct thermal contact with the fluid stored in the nozzle chamber at both opposed planar sides. The first heater element is formed on a different layer to the second heater element. The first heater element is formed with a surface area larger than that the second heater element.