JP4067891B2 - Electrostatic actuator, droplet discharge head, ink jet recording apparatus - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention relates to an electrostatic actuator, a droplet discharge head, and an ink jet recording apparatus.
[0002]
[Prior art]
In recent years, the development of fine electromechanical systems (generally MEMS: Mirco Electro Mechanical Systems) using manufacturing technology for semiconductor devices and liquid crystal display devices has been developed, especially for applications in fine optical systems and bioanalytical systems. In addition, it has been put to practical use as an ink jet head used in an ink jet recording apparatus for image output and other liquid droplet ejection heads.
[0003]
As an ink jet head that is a droplet discharge head, a diaphragm that forms a wall surface of a discharge chamber using an electromechanical transducer (piezoelectric actuator) such as a piezoelectric element as a pressurizing unit (pressure generating unit, actuator) is used. Ink droplets are generated by ink film boiling using an electrothermal transducer (thermal actuator) such as a piezo-type device that discharges ink droplets by deformation and displacement, or a heating resistor disposed in the discharge chamber. A thermal type that discharges ink, and an electrostatic type that discharges ink droplets by deforming the vibration plate with electrostatic force using a diaphragm that forms the wall surface of the discharge chamber and an electrode (electrostatic actuator) facing the diaphragm There are things. In addition, there is an electrostatic attraction type in which an ink droplet is ejected by electrostatic attraction using an electrode (electrostatic attraction actuator) that is provided on the recording medium side by applying an electric charge to the ink.
[0004]
In such an ink jet head, it is normal that all the actuators are installed on a one-to-one basis corresponding to each of the plurality of nozzle holes, and therefore, the same number of driving devices for driving the actuators are usually required. . However, in order to suppress excessive heat generation in a thermal actuator, a plurality of thermal actuators corresponding to a plurality of nozzles may be driven by a single driving device by matrix driving.
[0005]
Thus, in general, the number of drive devices equal to the number of actuators is generally composed of a drive circuit chip configured on a separate substrate from the actuators in piezoelectric actuators, electrostatic actuators, and electrostatic attraction actuators. A thermal actuator is generally configured on the same substrate.
[0006]
This difference is because the thermal actuator is configured on a silicon substrate that can be easily integrated, whereas the piezoelectric actuator, electrostatic actuator, and electrostatic attraction actuator are difficult to form on the silicon substrate due to the manufacturing process. .
[0007]
In other words, the above-described elements (other than the thermal actuator) that cannot form a drive circuit that selectively transmits image information to the actuator to be driven on the same substrate are one-to-one with the drive device in the drive circuit chip, and FPC (Flexible Printed Circuits) Need to be connected by wire bonding).
[0008]
In this case, the process yield in which the drive circuit chips are connected one-to-one to the potential supply / extraction portion (generally referred to as a pad) of the actuator by FPC or wire bonding strongly depends on the number of pads and the pad size, and the head In particular, there is a problem that the yield of products is lowered by increasing the density (high integration) and increasing the area (increasing the number of actuators in one chip).
[0009]
Moreover, the fine limit of the connection by the FPC or wire bonding is about 30 to 40 μm at present, and it can be said that this prevents an increase in the density and area of the actuator and a product using the actuator.
[0010]
Furthermore, for example, when configuring a line-type inkjet head (a print area is formed over one side of the paper and the head itself does not need to move), a 1000-pin drive circuit chip is formed when the paper is A4 or A3 size. There are also problems that dozens of them are required, thereby significantly increasing the cost of the product. In addition, since the line-type inkjet head does not need to move, the strength of the mechanism that holds it can be reduced, and at the same time, there is no vibration associated with the movement, and printing is performed simultaneously on one side of the paper. It is possible to provide a low-vibration and high-speed inkjet recording apparatus, and it is a head that should be put to practical use in the future.
[0011]
As described above, it is important to install the drive circuit on the same substrate as the actuator or bonded to the actuator substrate, but what is possible at present is the thermal actuator. However, since the thermal actuator generates a large amount of heat during operation, it has a problem that it is difficult to simultaneously drive the continuous elements and the power consumption is high. Furthermore, since it is necessary to form on a silicon substrate, there is a problem that it is difficult to increase the area of one chip.
[0012]
As a method of forming a driving device on the same substrate other than the above thermal actuator, a method can be considered in which a plurality of thin film transistors are provided for each actuator on the same substrate as the actuator formed on the glass substrate. However, for example, when the actuator is an image forming device or a video display device, it is necessary to operate a plurality of actuators in time according to the image input signal, and it is essential to simultaneously form an element (memory) for storing image information. It becomes.
[0013]
For this reason, there is a problem that the number of functional elements included in the driving device for operating one actuator in a timely manner is increased, and the manufacturing yield is significantly reduced. In addition, the area ratio occupied by the increased functional elements is large, and there is a problem that obstructs high density of products. Furthermore, a good memory element using a thin film has not been obtained at present.
[0014]
Here, as an ink jet recording apparatus equipped with a conventional ink jet head, for example, as disclosed in JP-A-8-238774, an ink jet recording apparatus equipped with an ink jet head using an electrostatic suction actuator is used. A control element for controlling the ejection of ink and a process control for controlling the control element between an electrode for electrostatic field application embedded in the side wall of the ink ejection chamber and a high-voltage power supply for applying the voltage The control element unit further includes a light emitting unit and a photoconductive unit, and the operation of the light emitting unit is controlled by a light emission amount control unit provided separately in the process control unit so that the photoconductive unit receives light. The resistance of the electrostatic field application electrode and the voltage in front of the nozzle hole are controlled by controlling the voltage of the electrostatic field application electrode part embedded in the side wall of the ink ejection chamber. Is known to control the potential difference with the counter electrode portion disposed in the nozzle, to apply charge to the ink in the ink ejection chamber, so that the charged ink is electrostatically attracted toward the counter electrode portion. It has been.
[0015]
  Patent No. 3030787In the newsAs disclosed, in an inkjet head in which a plurality of piezoelectric actuators are arranged in parallel, one electrode of each piezoelectric actuator is independently connected to a photoconductor, and the other electrode is commonly connected to an arbitrary potential. It is known that a plurality of photoconductors are selectively irradiated with light by an optical scanning means, and thereby a piezoelectric actuator is selectively deformed to eject ink droplets.
[0016]
In addition to the droplet discharge heads described above, optical cross-connects used as optical transmission devices have been put into practical use as belonging to MEMS. At present, the means for transmitting information is mainly based on electrical equipment, but as the amount of information increases, the use of light transmitting means, that is, optical transmission devices, is gradually increasing. The main application of optical transmission at present is to transmit between cities, countries, and continents using optical fibers. Among them, optical cross-connects operate multiple reflecting mirrors individually to select optical paths and separate them from optical fibers. It is used for the purpose of transmitting optical information to the optical fiber.
[0017]
[Problems to be solved by the invention]
First, in the above-described conventional inkjet recording apparatus, the electric potential of the electrostatic field applying electrode, which is an actuator, is controlled by light. In this apparatus, the control element unit is installed on the same substrate as the actuator. In addition, there is a problem that the connection yield is reduced and the cost is increased due to the FPC and wire bonding described above, and furthermore, since it is an electrostatic attraction method, a high drive voltage (several thousand volts) is required, and electromagnetic noise due to it is reduced. There is a problem that the power consumption is large in order to impart the ink to the problem of generation and charge.
[0018]
In addition, in an inkjet head that combines a piezoelectric actuator and a photoconductor, it is difficult to make a fine pattern in the first place, and the current printing piezo method has a limit of 400 dpi (dots per inch). Moreover, since 300 dpi is considered to be the limit in the dicing method of the laminated piezo element, there is a problem that it is difficult to increase the density of the head, particularly 1200 dpi or more.
[0019]
Next, it is considered that the above-described optical transmission technology can be used in offices and devices as the amount of information increases in the future. In this case, the optical cross-connect device used in the large-scale optical communication network is used. In the same way as in the office and equipment, an optical path switching device is required. As represented by the current optical cross-connect device, the optical path switching device is operated by an electrical signal to operate the optical path switching actuator. What can be considered.
[0020]
However, driving the optical path switching device with an electric signal causes a delay in information transmission caused by passing through a large number of metal wirings in the driving device, and thus hinders speeding up of the response of the optical path switching. It is thought that this problem will surface. In addition, electromagnetic noise caused by the driving device is expected to increase in accordance with high-speed operation, and there arises a problem of how to reduce the electromagnetic noise.
[0021]
  The present invention has been made in view of the above problems, and an electrostatic actuator that can achieve high density, large area, high yield, and low cost.,Droplet discharge head, inkjet recording devicePlaceThe purpose is to provide.
[0022]
[Means for Solving the Problems]
  In order to solve the above problems, an electrostatic actuator according to the present invention is:
  Opposing to the movable member and this movable memberFixedA conductive member, and an actuator unit that deforms or displaces the movable member by electrostatic force by applying a potential to the conductive member.In the electrostatic actuator
  A conductive member made of a light transmissive member is provided on the actuator substrate made of a light transmissive member.An optical response member that responds to light is provided integrally,Light is irradiated through the actuator substrate and the conductive memberVia photoresponsive memberLeadElectric potential is applied to the electric member
The configuration.
[0023]
  Here, the photoresponsive member is preferably a rectifying photoconductor, and the photoresponsive member is preferably formed of a silicon-based film.. MaIn addition, it is preferable that a plurality of actuator units and optical response members corresponding to the actuator units are provided, and the potential input sides of the optical response members are connected in common.
[0027]
In the liquid droplet ejection head according to the present invention, the pressurizing means for pressurizing the liquid in the liquid chamber is constituted by the actuator portion of the electrostatic actuator according to the present invention. Here, the head is preferably a line type head.
[0028]
  The ink jet recording apparatus according to the present invention comprises an ink jet head that ejects ink droplets from a nozzle, using the liquid droplet ejection head according to the present invention.It was.
[0029]
  Here, a light source that emits light in accordance with drive information and a scanning unit that scans the light emitted from the light source with respect to each light response member of the plurality of actuator units can be used. In this case, the light responsive member of the actuator unit of the droplet discharge head is irradiated with light to give a potential to the conductive member, and the movable member is displaced or deformed almost simultaneously with the light irradiation by the potential difference with the potential of the movable member. it can. Alternatively, light is applied to the photoresponsive member of the actuator unit of the droplet discharge head to apply a potential to the conductive member, and after the light is applied, a predetermined potential is applied to the movable member to cause a potential difference between the conductive member and the movable member. And the movable member can be displaced or deformed after light irradiation. In addition, the potential of the conductive member can be reset to the initial potential after the movable member is displaced or deformed. further,One light source for one droplet discharge head can be configured as one.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. A first embodiment of an electrostatic actuator according to the present invention will be described with reference to FIGS. 1 is a cross-sectional explanatory diagram along the longitudinal direction of the movable member of the actuator, FIG. 2 is a plan explanatory diagram of the actuator, and FIG. 3 is an explanatory diagram for explaining a layer structure of a light response member of the actuator.
[0033]
In this electrostatic actuator, the insulating film 2 is provided on the actuator substrate 1, the movable member 3 is provided on the opening side of the concave portion 2 a formed in the insulating film 2, and the concave portion 2 a is formed on the actuator substrate 1. The conductive member 4 is provided on the bottom side, and the movable member 3 and the conductive member 4 are opposed to each other through the gap 5 formed by the recess 2 a provided in the insulating film 2. An electrostatic actuator unit 6 that deforms and displaces the movable member 3 with an electrostatic force is formed by the opposing conductive member 5.
[0034]
Further, the conductive member 4 on the actuator substrate 1 is pulled out of the actuator portion 6 to form a lead portion 4a, and a light response member 7 that responds to light is provided on the lead portion 4a in an electrically connected state. Thus, the conductive member 4 is provided in contact with the photoresponsive member 7, and a potential supply line (member) 8 formed on the insulating film 2 is connected to the potential input side of the photoresponsive member 7. The photoresponsive member 7, the lead-out portion 4 a of the conductive member 4, and the potential supply line 8 constitute a drive unit 9 for driving / non-driving the actuator unit 6. By providing the light response member 7 on the actuator substrate 1 in this way, the electrostatic actuator is provided with the light response member 7 integrally.
[0035]
Here, as the actuator substrate 1, it is preferable to use a substrate generally used in a semiconductor process or a liquid crystal process such as a silicon substrate or a glass substrate for miniaturization. In this embodiment, the outer side of the actuator substrate 1 is used. Since light (light driving signal) 10 is incident on the light response member 7 from the light transmitting member 7, a light transmitting member, for example, a transparent glass substrate is used.
[0036]
The insulating film 2 may be any film that can be formed on the actuator substrate 1, and may be deposited on the substrate 1, or when the substrate 1 is an insulating substrate, the substrate 1 itself is etched. You may form by processing.
[0037]
The movable member 3 is formed of a member having at least a part of conductivity. Note that a part of the material having conductivity includes a case where a conductive member is deposited on an insulating base material or a conductive film (layer) is laminated on an insulating base material. It is. In this embodiment, the movable member 3 is composed of a single layer or a stacked layer of nickel, titanium, aluminum, polycrystalline silicon, crystalline silicon, and a silicon nitride film.
[0038]
The conductive member 4 is not particularly limited as long as it is a conductive member. However, when the light (light driving signal) 10 is incident on the light response member 7 from the outside of the actuator substrate 1, the conductive member 4 is conductive. The conductive member 4 is also formed of a member that transmits light, for example, a transparent member. Here, the conductive portion 4 has a structure in which both ends are terminated by the light response member 7 and the actuator portion 6 and are electrically floating.
[0039]
In this way, the conductive member (or part thereof) is provided in contact with the portion of the light-responsive member that is irradiated with light, and the conductive member is formed of a member that transmits light, thereby transmitting the conductive member. Thus, it is possible to irradiate the light response member with light, and the electrostatic actuator and its driving device can be miniaturized.
[0040]
The photoresponsive member 7 is composed of a photoconductor or a photovoltaic film. The material of the photoresponsive member 7 includes the irradiation time of the irradiated optical drive signal 10 and the movement time of the generated carriers, that is, the time for moving through the photoresponsive member 7 and determining the potential of the conductive member 4, the conductivity It is determined by the potential of the member 4 (the potential of the conductive member 4 is determined by the partial pressure due to the ON resistance at the time of light drive signal irradiation). For example, amorphous silicon or amorphous selenium, which is an inorganic photoreceptor, an organic photoreceptor, a multilayer amorphous silicon thin film, crystalline silicon, or the like can be used.
[0041]
The photoresponsive member 7 is provided for each of the plurality of actuator units 6 and is provided separately from each other.
[0042]
The photoresponsive member 7 is preferably a rectifying photoconductor such as a pn junction pin structure. For example, an amorphous silicon-based laminated film or a crystalline silicon p-type n-type junction film is preferably used. .
[0043]
For example, as shown in FIG. 3, the photoresponsive member 7 is composed of a laminated film of amorphous silicon films 11, 12, and 13, and the amorphous silicon 11 in contact with the lead portion 4 a of the conductive member 4 is A p-type semiconductor amorphous silicon film mixed with boron (boron) is formed, and an upper film 12 is an i-type (intrinsic) semiconductor that is not mixed with impurities, and a film thereabove. Reference numeral 13 denotes an n-type semiconductor amorphous silicon film mixed with phosphorus.
[0044]
Thus, by using the amorphous silicon-based laminated film having the pin structure as the photoresponsive member 7, when the pin is forward-biased, that is, when the p-type semiconductor 11 is relatively positive, the current is increased. When the current flows and is biased in the reverse direction, that is, when the n-type semiconductor 13 is set to a relatively positive potential, the photoconductor has a rectifying property in which no current flows.
[0045]
When the light responsive member 7 is irradiated with light, even when biased in the reverse direction, carriers are generated along with the light irradiation, the resistance of the light responsive member 7 is lowered, current flows, and the conductive member 4 is allowed to flow freely. It can be a potential. Further, by biasing the p-type semiconductor 11 in the forward direction, the potential of the conductive member 4 can be reset to the initial value. The amorphous silicon film can be formed by continuous film formation by, for example, a plasma CVD method by changing the film formation conditions for each layer.
[0046]
In this way, by making the photoresponsive member a rectifying photoconductor such as a pn junction or a pin structure, the potential of the conductive member of the electrostatic actuator can be determined by resistance change according to light irradiation. In addition, by relatively positively biasing the p-type semiconductor, the potential of the conductive member can be reset to the initial value, and the operation of the electrostatic actuator can be arbitrarily controlled.
[0047]
Moreover, the optical response member 7 according to the manufacturing process of an electrostatic actuator can be obtained by comprising the optical response member 7 with a silicon film. That is, when the upper limit temperature of the manufacturing process of the actuator portion 6 is about 400 ° C. or less, a photoresponsive member having a pin structure can be configured using an amorphous silicon film, and the upper limit temperature of the manufacturing process of the actuator portion 6 is about 600 ° C. In the following cases, the light-responsive member 7 having a pn junction structure can be configured using a recrystallized silicon film recrystallized by laser irradiation. When the manufacturing process uses a silicon substrate, the actuator has a pn junction structure made of crystalline silicon. The light response member 7 can be configured.
[0048]
That is, the light response member 7 suitable for the manufacturing process of the actuator can be obtained by using the silicon film as the light response member 7. Moreover, the optimal optical response member 7 can be obtained according to the irradiation time of the optical drive signal 10 irradiated to the optical response member 7. That is, when the irradiation time of the optical drive signal 10 irradiated to the optical response member 7 is relatively long, such as several tens of nsec to several μsec, the mobility is 0.5 to 10 cm.²A photoresponsive member having a pin structure can be formed using a relatively slow amorphous syringe film of / V / sec, and the mobility is 400 to 1000 cm when the irradiation time of the optical drive signal 10 is relatively short of several nsec or less.²The photoresponsive member 7 having a pn junction structure can be formed using a recrystallized silicon film or a crystalline silicon film that is as fast as / V / sec.
[0049]
The potential supply line 8 is formed of a metal wiring such as aluminum, chromium, titanium, titanium nitride or the like. A potential applied to the conductive member 4 from the outside is applied to the potential supply line 8. Here, the potential supply line 8 is provided for each conductive member 4 of each actuator unit 6.
[0050]
In the electrostatic actuator configured as described above, for example, the optical drive signal 10 is supplied to the actuator in a state where the movable member 3 is set to the ground potential and a predetermined potential (first potential) is supplied to the potential supply line 8 from the outside. Incidence (light irradiation) from the outside of the substrate 1 to the photoresponsive member 7 through the conductive member 4 changes the resistance value of the photoresponsive member 7, and a first potential is applied to the conductive member 4. Due to the potential difference from the potential of the movable member 3, an electrostatic force is generated between the movable member 3 and the conductive member 4, and the movable member 3 is deformed and displaced toward the conductive member 4.
[0051]
At this time, the optical actuator 10 is incident only on the optical response member 7 of the driving unit 9 corresponding to the target actuator unit 6 (selectively irradiates light), whereby the required actuator unit 6 can be moved. The member 3 can be selectively deformed and displaced (operated).
[0052]
As described above, in this electrostatic actuator, a plurality of one-dimensional (or two-dimensional) actuator members arranged on the same substrate (or the actuator member) as opposed to the movable member of the actuator unit are arranged. Since the required potential is applied via the photoresponsive member provided in the actuator substrate, any actuator unit can be operated by the optical drive signal incident on the photoresponsive member. Therefore, it is not necessary to connect a large number of expensive driving chips by wire bonding or the like.
[0053]
As a result, even when the drive voltage of the actuator unit is high or when driving tens of thousands of actuator units, it is possible to cope with high density (high integration) and large area of actuators (the number of actuators in one chip). Increase), high yield, and low cost.
[0054]
In other words, a drive unit including a light response member can be provided on the same substrate as the actuator unit or bonded to the actuator substrate, and light can be incident on the light response member according to the purpose to operate the actuator unit in a timely manner. Each drive unit that drives the actuator unit can be easily configured on the same substrate or bonded, and the number of wire bonding and FPC connection can be greatly reduced compared to the conventional configuration with separate chips, resulting in higher density The product yield of the actuator can be improved, and the restriction of the connection area with the connection means can be eliminated. Therefore, the density and area can be increased, and the cost can be reduced. Further, the area ratio of the actuator can be increased and the density can be increased in that a complicated drive circuit is not required.
[0055]
In addition, since the electrostatic actuator can be driven by an optical drive signal, the drive voltage applied to each actuator unit is not limited by the drive unit (drive device), and the drive voltage can be easily increased. Thus, the actuator performance can be improved. When the drive unit is configured as a separate chip as in the prior art, an increase in the drive voltage causes an increase in the cost of the drive unit, but such a cost increase is eliminated.
[0056]
Furthermore, since each drive unit that drives a plurality of actuator units can be easily configured on the same substrate or bonded, when the drive unit is configured with another chip, the number of drive chips increases as the number of actuators increases. In the electrostatic actuator according to the present invention, the drive means (drive circuit) for on / off control of the optical drive signal can be configured by one, and the cost can be greatly reduced.
[0057]
Furthermore, the structure of the drive unit for driving the actuator unit is simple, and it is not necessary to go through a large number of metal wires, delaying information transmission caused by metal wires can be suppressed, and the actuator operation speed can be increased. In addition, generation of electromagnetic noise can be suppressed.
[0058]
Next, a second embodiment of the electrostatic actuator according to the present invention will be described with reference to FIGS. 4 is a cross-sectional explanatory diagram along the longitudinal direction of the movable member of the actuator, FIG. 5 is a plan explanatory diagram of the actuator, and FIG. 6 is an explanatory diagram for explaining the layer structure of the optical response member of the actuator.
[0059]
In this electrostatic actuator, the actuator substrate 1 does not need to be transparent because the optical drive signal 10 is incident from above, and a silicon substrate is used here. A silicon oxide film is used as the insulating film 2 on the actuator substrate 1.
[0060]
An engraved portion 1a is formed on the actuator substrate 1 by etching, and a light response member 17 is provided in the engraved portion 1a. The photoresponsive member 17 is a pn junction film of crystalline silicon as shown in FIG. That is, the portion in contact with the conductive member 4 is a crystalline silicon film 21 which is a p-type semiconductor mixed with boron, and the portion connected to the potential supply line 8 is an n-type mixed with phosphorus. A crystalline silicon film 23 which is a semiconductor is used.
[0061]
Then, the lead portion 4a of the conductive member 4 is brought into contact (electrical bonding) with the crystalline silicon film 21 of the light response member 17 on the surface side of the actuator substrate 1, and the potential supply line 8 is brought into contact with the crystalline silicon film 23 (electrical). The electric potential applied from the outside to the electric potential supply line 8 is applied to the conductive member 4 of the actuator section 6 via the photoresponsive member 17.
[0062]
In the electrostatic actuator configured as described above, when the pn is biased in the forward direction, that is, when the p-type semiconductor 21 is set to a relatively positive potential, a current flows and the photoresponsive member 17 in the reverse direction. When biased, that is, when the n-type semiconductor 23 has a relatively positive potential, a photoconductor having a rectifying property in which no current flows is obtained.
[0063]
Here, when the light responsive member 17 is irradiated with light, even when biased in the reverse direction, carriers are generated along with the light irradiation, the resistance of the light responsive member 17 decreases, and a current flows, so that the conductive member 4 Can be any potential. Furthermore, the potential of the conductive member 4 can be reset to the initial value by biasing the p-type semiconductor 21 in the forward direction.
[0064]
Since the light-responsive member 17 having a pn junction structure made of crystalline silicon is used as the light-responsive member 17, the mobility is 500 to 1000 cm even when the irradiation time of the light driving signal 10 is relatively short, such as several nsec.²Due to the high speed of / V / sec, the potential of the potential supply line 8 can be supplied to the conductive member 4.
[0065]
Next, a first embodiment of an inkjet head, which is a droplet discharge head according to the present invention, will be described with reference to FIGS. 7 is a cross-sectional explanatory diagram along the longitudinal direction of the movable member (diaphragm) of the head, and FIG. 8 is a plan explanatory diagram of the head.
[0066]
This ink jet head is a side shooter type head, and is a combination of the electrostatic actuator described in the first embodiment of the electrostatic actuator according to the present invention, the flow path substrate 41 and the nozzle plate 42. is there.
[0067]
That is, a structure in which a flow path substrate 41 is laminated on an insulating film 32 provided on an actuator substrate 31 of an electrostatic actuator, and a nozzle plate 42 is further laminated on the flow path substrate 41, whereby ink droplets are formed by these. A pressure liquid chamber 46, which is a flow path through which the nozzle 45 to be discharged communicates, and a common liquid chamber 48 for supplying ink to the pressure liquid chamber 46 via a fluid resistance portion 47 are formed.
[0068]
The flow path substrate 41 is made of a single crystal silicon substrate, and includes a pressurizing liquid chamber 46 and a recess for forming a diaphragm 50 that is a movable member that constitutes a bottom surface that is a wall surface of the pressurizing liquid chamber 46. A concave portion for forming a common liquid chamber 48 for supplying ink to the pressure liquid chamber 46 and a groove portion serving as a fluid resistance portion 47 for communicating the pressurized liquid chamber 46 and the common liquid chamber 48 are provided.
[0069]
The diaphragm 50 is formed by doping boron atoms formed by doping a silicon substrate forming the flow path substrate 41 with high-concentration boron at 1E20 / cm.³The above-described high-concentration boron diffusion layer can be formed. Alternatively, the diaphragm 50 can be formed of an active layer of an SOI (Silicon on Insulator) substrate, a conductive thin film such as a metal, or the like. it can. An insulating thin film, such as a silicon oxide film or a silicon nitride film, is formed on the outer surface side (surface opposite to the pressurized liquid chamber) of the diaphragm 50.
[0070]
The actuator substrate 31 is opposed to the diaphragm 50, which is a movable member, through a predetermined gap 35 formed by a recess formed in the insulating film 32, as in the first embodiment of the electrostatic actuator described above. A pressure member for pressurizing ink, which is a liquid in the pressure liquid chamber 46, by providing the conductive member 34 to be deformed and deforming and displacing the diaphragm 50 with an electrostatic force by the diaphragm 50 and the conductive member 34. The actuator section 36 is configured.
[0071]
In addition, a lead-out portion 46a that pulls the conductive member 34 out of the actuator portion 36 is electrically connected to the photoresponsive member 37, and a potential supply line 38 is connected to the potential input side of the photoresponsive member 37. A drive unit 39 for driving the actuator unit 36 is configured. Here, the potential supply line 38 corresponding to each actuator unit 36 is commonly connected to all channels (actuator units 36) via the common connection unit 38a. The light response member 37 has the same configuration as the light response member 7 described above.
[0072]
A plurality of nozzles 45 for ejecting ink droplets are arranged and formed on the nozzle plate 43. As this nozzle plate 43, what consists of metals, such as stainless steel and nickel, resin, such as a polyimide resin film, a silicon wafer, and those combinations, can be used. Further, a water repellent film is formed on the nozzle surface (surface in the ejection direction: ejection surface) by a known method such as a plating film or a water repellent coating in order to ensure water repellency with ink.
[0073]
In the ink jet head configured as described above, for example, light is transmitted from the outside of the actuator substrate 31 through the conductive member 34 in a state where the diaphragm 50 is set to the ground potential and a required potential is supplied to the potential supply line 38 from the outside. When the light driving signal 40 is incident on the response member 37, the resistance value of the light response member 37 is changed, and a required potential is given to the conductive member 34. An electrostatic force is generated between the conductive member 34 and the diaphragm 50 is deformed and displaced toward the conductive member 34.
[0074]
As a result, the internal volume of the pressurizing liquid chamber 46 is increased and ink is replenished from the common liquid chamber 48 to the pressurizing liquid chamber 46 via the fluid resistance portion 47. In this state, the potential of the conductive member 34 is reduced, for example. By making it the same as the potential of the diaphragm 50 (a potential that does not cause a potential difference between the diaphragm 50 and the conductive member 34 is given to the conductive member 34), the diaphragm 50 and the conductive member 34 are disposed. The electrostatic force disappears and the diaphragm 50 is restored and deformed, so that the ink in the pressurized liquid chamber 46 is pressurized and ink droplets are ejected from the nozzle 45.
[0075]
At this time, the optical drive signal 40 is incident only on the optical response member 37 of the drive unit 39 corresponding to the target actuator unit 36, whereby the diaphragm 50 of the required actuator unit 36 is selectively deformed and displaced. Ink droplets can be ejected.
[0076]
Thus, by providing the droplet discharge head with the electrostatic actuator according to the present invention, it becomes possible to operate an arbitrary actuator unit (pressurizing means) by an optical drive signal incident on the optical response member, which is expensive. It is not necessary to connect a large number of drive chips by wire bonding or the like, and it is possible to achieve high density (high integration), large area, high yield, and low cost of the ink jet head (droplet discharge head).
[0077]
Next, a second embodiment of an inkjet head, which is a droplet discharge head according to the present invention, will be described with reference to FIGS. FIG. 9 is an explanatory sectional view of the head along the longitudinal direction of the movable member, and FIG. 10 is an explanatory plan view of the head. In addition, the same code | symbol is attached | subjected and demonstrated to the part corresponding to 1st Embodiment.
[0078]
This inkjet head is an edge shooter type head, and is a combination of the electrostatic actuator described in the second embodiment of the electrostatic actuator according to the present invention, the flow path substrate 41 and the top plate 44. is there.
[0079]
That is, a structure in which a flow path substrate 41 is laminated on an insulating film 32 provided on an actuator substrate 31 of an electrostatic actuator, and a top plate 44 is further laminated on the flow path substrate 41, and ink drops are thereby formed. A pressure liquid chamber 46 that is a flow path through which the nozzle 45 to be discharged communicates, and a common liquid chamber 48 that supplies ink to the pressure liquid chamber 46 via an ink supply path (communication portion) 47 that serves as a fluid resistance portion are formed. ing.
[0080]
The flow path substrate 41 is made of a single crystal silicon substrate, and is a diaphragm that is a movable member that constitutes a groove serving as the nozzle 45, a pressurized liquid chamber 46 that communicates with the nozzle 45, and a bottom surface that is a wall surface of the pressurized liquid chamber 46. 50, a recess for forming a common liquid chamber 48 for supplying ink to each pressurized liquid chamber 46, and a fluid that communicates the pressurized liquid chamber 46 and the common liquid chamber 48. It has a groove portion that becomes the resistance portion 47. A water repellent film is formed around the nozzle 45 as in the first embodiment.
[0081]
In this case as well, the diaphragm 50 has a boron atom of 1E20 / cm formed by doping the silicon substrate forming the flow path substrate 41 with high-concentration boron.³The above-described high-concentration boron diffusion layer can be formed. Alternatively, the diaphragm 50 can be formed of an active layer of an SOI (Silicon on Insulator) substrate, a conductive thin film such as a metal, or the like. it can. An insulating thin film, such as a silicon oxide film or a silicon nitride film, is formed on the outer surface side (surface opposite to the pressurized liquid chamber) of the diaphragm 50.
[0082]
The actuator substrate 31 is opposed to the diaphragm 50, which is a movable member, through a predetermined gap 35 formed by a recess formed in the insulating film 32, as in the second embodiment of the electrostatic actuator described above. The electroconductive member 34 is provided, and the diaphragm 50 and the electroconductive member 34 are deformed and displaced by the electrostatic force by the diaphragm 50 and the electroconductive member 34 to form a pressurizing unit for pressurizing the ink that is the liquid in the liquid chamber 46. The actuator part 36 is comprised.
[0083]
In addition, a lead portion 34 a from which the conductive member 34 is drawn out of the actuator portion 36 is electrically connected to a light response member 37 embedded in the actuator substrate 31, and a potential formed on the insulating film 32 on the light response member 37. A supply line 38 is connected to form a drive unit 39 for driving the actuator unit 36. Here, the potential supply line 38 corresponding to each actuator section 36 is commonly connected to all channels via a common connection section 38a. The light response member 37 has the same configuration as the light response member 17 described above.
[0084]
In the ink jet head configured as described above, for example, a light drive signal 40 is incident on the light response member 37 from above the actuator substrate 31 in a state where a required potential is supplied to the potential supply line 38 from the outside. The resistance value of the response member 37 changes, and the conductive member 34 is determined to have an arbitrary potential. At this time, since the potential difference between the diaphragm 50 and the conductive member 34 is set to a potential difference that does not cause the diaphragm (movable member) 50 to be largely displaced and deformed, the diaphragm 50 is on the conductive member 34 side. Will not be drawn to. Therefore, ink is not supplied to the pressurized liquid chamber 46 via the fluid resistance portion 37 at this stage.
[0085]
When another arbitrary potential is supplied to the diaphragm 50 at the time when the scanning of the light driving signal 40 for all the print areas is completed, the potential difference between the diaphragm 50 and the conductive member 34 increases, and the diaphragm 50 It is displaced and deformed, and is drawn toward the conductive member 34 side. As a result, ink is supplied to the pressurized liquid chamber 36. That is, the first operation of the actuator unit is performed. This first operation is performed simultaneously in all selected actuator units.
[0086]
Thereafter, when another arbitrary potential is supplied to the potential supply line 38, the photoresponsive member 37 is biased in the forward direction, the potential of the conductive member 34 is reset to the initial value, and all of the potential drawn to the conductive member 34 side is obtained. The diaphragm 50 of the actuator portion 36 returns to its original position, and ink droplets are ejected from the nozzle 45 corresponding to the selected element (channel).
[0087]
At this time, the optical drive signal 40 is incident only on the optical response member 37 of the drive unit 39 corresponding to the target actuator unit 36, whereby the diaphragm 50 of the required actuator unit 36 is selectively deformed and displaced. Ink droplets can be ejected.
[0088]
Next, an ink jet recording apparatus according to the present invention including the driving apparatus according to the first embodiment of the electrostatic actuator driving apparatus according to the present invention will be described with reference to FIGS. 11 is a schematic perspective explanatory view of the recording apparatus, FIG. 12 is a schematic configuration diagram of the recording apparatus, and FIG. 13 is a schematic configuration diagram of a head portion of the recording apparatus.
This ink jet recording apparatus has a long line type ink jet head 63 which is a liquid droplet ejection head according to the present invention having substantially the same width as a paper 62 which is a recording medium to be printed (recorded) in a recording apparatus main body 61. , The paper 62 is fed by the paper feed roller 64, and the required image is recorded on the paper 62 by the line-type inkjet head 63 while the paper 62 is being transported by the transport roller 65. To do.
[0089]
Here, as shown in FIG. 13, the line type ink jet head 62 is an ink jet head 71 which is a droplet discharge head according to the present invention, and the present invention for irradiating each light response member of the ink jet head 71 with scanning light. And a scanning light source system 72 constituting the electrostatic actuator driving apparatus according to the present invention.
[0090]
The ink-jet head 71 has the same configuration as that of the ink-jet head described in the first or second embodiment of the ink-jet head, which is the droplet discharge head according to the present invention described above, and the nozzle 45 is arranged in the sub-scanning direction (of the paper 62). It is formed at a predetermined pitch in a width region substantially the same as the sheet 62 in a direction orthogonal to the (conveying direction). When a predetermined image density cannot be obtained with a single nozzle arrangement, two nozzles are arranged in a staggered pattern. In this case, two sets of the scanning light source systems 72 may be used to supply the optical drive signals to the optical response members corresponding to the nozzles in each row.
[0091]
The scanning light source system 72 emits laser light (light drive signal) in accordance with print information (image information) that is drive information, and the laser light from the laser light source 81 is output to each light of the inkjet head 71. Each optical response member 37 of the line-type inkjet head 71 includes a scanning optical system that is a scanning unit including a collimating lens 82 for entering the response member 37, a polygon mirror 83, a scanning lens 84, and a folding lens 85. Is optically scanned in the line direction.
[0092]
Next, the operation of the ink jet recording apparatus will be described including the operation of the electrostatic actuator driving apparatus according to the present invention.
First, in the scanning light source system 72, a light drive signal (laser light) corresponding to printing information (recording information) is emitted from the semiconductor laser light source 81 and enters the polygon mirror 83 via the collimator lens 82. The optical drive signal 40 is scanned in accordance with the rotation of the polygon mirror 83, is enlarged to the printing area by the scanning lens 84, is reflected back by the folding mirror 85, and is one of the aligned optical response members 37 of the inkjet head 71. The required light response member 37 is irradiated.
[0093]
Here, as described above, in the inkjet head 71, the resistance of the light response member 37 irradiated with the light driving signal 40 changes, and the potential of the conductive member 34 is determined to be an arbitrary value. At this time, an electrostatic force is generated between the diaphragm 50 and the conductive member 34 due to a potential difference with the diaphragm (movable member) 50 that is the second potential, and the diaphragm 50 is displaced and deformed toward the conductive member 34. Then, it is drawn toward the conductive member 34 side. As a result, ink is supplied from the common liquid chamber 48 into the pressurized liquid chamber 46 via the fluid resistance portion 47. That is, the first operation of the electrostatic actuator 36 is performed.
[0094]
Next, another arbitrary potential is applied to the potential supply line 38 when the scanning of the light driving signal 40 for all the print areas is completed. As a result, the photoresponsive member 37 is biased in the forward direction, the potential of the conductive member 34 is reset to the initial value, and the diaphragm 50 which is a movable member of all electrostatic actuators drawn toward the conductive member 34 side. The ink droplet 86 is ejected from the nozzle hole 45 corresponding to the selected actuator section 36 (channel). That is, the second operation of the electrostatic actuator is performed.
[0095]
As described above, image information (printing) is provided by including one light source that emits light according to drive information and means for scanning the light response members of the plurality of actuator units with the light emitted from the light source. Each light responsive member can be scanned while turning on / off the light applied to each light responsive member according to the information), the number of light sources can be reduced to the minimum necessary, and the cost can be reduced and the size can be reduced. Can be achieved. In this case, the light irradiating the light response member is scanned using a polygon mirror. However, the scanning may be performed using a galvanometer mirror or the like.
[0096]
Thus, when using a line-type inkjet head, the light response members are aligned in the direction of one side of the paper through the actuator sections or between the heads (when using a plurality of head chips), and the light source is between the actuator sections. Alternatively, by adopting a configuration in which scanning is performed between the heads, it is possible to perform optical scanning with respect to the optical response member through one side of the paper, and the number of scanning light sources can be reduced, and cost can be further reduced.
[0097]
Further, by irradiating the optical response member with an optical drive signal as necessary, the potential of the conductive member is made equal to an arbitrary potential of the potential supply line, and a different potential supplied to the opposing movable member (vibrating plate) Due to this potential difference, the diaphragm is displaced or deformed almost simultaneously with the light irradiation, so that the ink can be supplied to the pressurized liquid chamber almost simultaneously with the light irradiation.
[0098]
Furthermore, the potential of the conductive member connected via the photoresponsive member can be reset to the initial potential by applying any different potential to the potential supply line of the conductive member after the diaphragm is displaced or deformed. Ink droplets can be ejected from the nozzle of the selected channel.
[0099]
Furthermore, since the displacement deformation operation of the diaphragm or the reset operation of the electric potential of the conductive member is simultaneously performed by the drive unit of the electrostatic actuator installed in plural, the channel ( Ink droplets can be simultaneously ejected from the nozzles of the selected channel among the nozzles), and the uniformity of the operation of each channel (actuator unit) can be improved.
[0100]
In addition, the inkjet head using the droplet discharge head according to the present invention is configured as a line-type inkjet head, that is, one or a plurality of inkjet heads are arranged over almost the entire area of one side of a sheet on which an image is printed. Therefore, a high-yield and high-density line-type inkjet head can be obtained, and a head capable of high-speed recording and recording high-definition images can be obtained at low cost. Furthermore, since there is no movement of the head, noise and vibration can be reduced.
[0101]
Next, a second embodiment of the electrostatic actuator driving apparatus in the ink jet recording apparatus will be described with reference to FIG.
First, when the paper size to be recorded is A4 size, the nozzles 45 of the inkjet head 71 are arranged in a line over the width (210 mm) in one side direction of the A4 size paper in series. Here, assuming that the density of the inkjet head 71 is 1200 dpi, a total of 9922 elements (driving unit 39, actuator unit 36, pressurized liquid chamber 46, nozzle hole 45: channel) are arranged within a width of 210 mm.
[0102]
If the specification of the ink jet recording apparatus is 5 ppm (print per min), the time allowed as a printing time for one A4 size sheet is about 10 seconds. At this time, the time allowed for printing by the inkjet head 71 having the nozzles in one row is 10 sec / (1200 × 297 / 25.4) = 10/14032 = 0.000713 sec, that is, 713 μsec. Therefore, it is necessary to finish scanning the optical drive signal 40 during this 713 μsec and eject ink droplets.
[0103]
At this time, if the optical scanning time is 700 μsec and the reset time is 13 μsec within one row printing time of 713 μsec, the optical response signal 37 of one element (one channel) within the optical scanning time is irradiated with the optical drive signal (light). The time taken is 70.6 nsec.
[0104]
In the inkjet head 71, the diaphragm 50 of each actuator unit 36 is formed from the flow path substrate 41 made of a silicon substrate. Therefore, when the potential is applied to the flow path substrate 41, all the vibration plates 50 are substantially omitted. Since the potential supply line 38 is common to all channels in the common connection portion 38a, all potential supply lines 38 are set to substantially the same potential by applying a potential to the potential supply line 38.
[0105]
First, at time T1, a potential V1 of + 20V is applied to the potential supply line 38 as shown in FIG. 14A, and a potential V2 of −20V is applied to the diaphragm 50 as shown in FIG. In addition, a potential of −20 V is applied to the potential Vx of the conductive member 34 in an intended state. Therefore, at this time T1, V1 = 20V, V2 = −20V, and Vx = −20V, so | V2−Vx | = 0V, and there is no static between the conductive member 34 and the diaphragm 50. No power is generated.
[0106]
Here, the light drive signal 40 is in a laser-on state (Leaser on) when scanning the light-responsive member 37 corresponding to the actuator unit 36 (channel) that discharges ink droplets in accordance with the image information, and the ink This signal is a laser off state (Leaser off) when scanning the light response member 37 corresponding to the actuator unit 36 that does not eject droplets.
[0107]
Therefore, in the channel irradiated with the optical drive signal 40, as shown in FIG. 6C, the potential Vx of the conductive member 34 corresponding to the optical response member 37 is Vx = 20 V. As shown in FIG. 4, the potential difference between the conductive member 34 and the diaphragm 50 is | V2−Vx | = 40 V, and an electrostatic attractive force acts between the diaphragm 50 and the conductive member 34, so that the diaphragm 50 is electrically conductive. The ink is supplied to the corresponding pressurized liquid chamber 46.
[0108]
On the other hand, in the channel where the optical drive signal 40 is not irradiated, the potential Vx of the conductive member 34 remains Vx = −20 V as shown in FIG. The potential difference between the member 34 and the diaphragm 50 is | V2−Vx | = 0 V, and electrostatic attraction is not generated between the diaphragm 50 and the conductive member 34, and the diaphragm 50 is not deformed and displaced.
[0109]
Then, the reset time is reached from the time point T2 in the figure when the scanning of the optical drive signals 40 for all the channels is completed while maintaining the state of the diaphragm 50 corresponding to the optical drive signal 40 for each channel.
[0110]
In this reset time, when the potential V1 with respect to the potential supply line 38 is set to V1 = −20V, the pin structure of the photoresponsive member 37 is biased in the forward direction, so that the potential Vx of the conductive member 34 becomes Vx = −20V. . As a result, the potential difference between the conductive member 34 and the diaphragm 50 becomes | V2−Vx | = 0 V in all the channels, and the deformed diaphragm 50 is restored to the original position, and ink is discharged from the corresponding nozzle 45. Drops are ejected.
[0111]
Next, a third embodiment of the electrostatic actuator driving device in the ink jet recording apparatus will be described with reference to FIG.
First, when the paper size to be recorded is A4 size, the nozzles 45 of the inkjet head 71 are arranged in a line over the width (210 mm) in one side direction of the A4 size paper in series. Here, assuming that the density of the inkjet head 71 is 1200 dpi, a total of 9922 elements (driving unit 39, actuator unit 36, pressurized liquid chamber 46, nozzle hole 45: channel) are arranged within a width of 210 mm.
[0112]
If the specification of the ink jet recording apparatus is 50 ppm (print per min), the time allowed for one A4 size sheet as the printing time is about 1 sec. At this time, the time allowed for printing by the inkjet head 71 having the nozzles in the row is 1 sec / (1200 × 297 / 25.4) = 11/14032 = 0.0000713 sec, that is, 71.3 μsec. Therefore, it is necessary to finish scanning the optical drive signal 40 during this 71.3 μsec and eject ink droplets.
[0113]
At this time, if the optical scanning time is 40 μsec, the deformation displacement time is 20 μsec, and the reset time is 11.3 μsec within one row printing time of 71.3 μsec, the optical response member of one element (one channel) of the optical scanning time. The time during which 37 is irradiated with the light drive signal (light) is 4 nsec. Thus, in order to satisfactorily apply the required potential Vx to the conductive member 34 in a relatively short irradiation time, the single-crystal silicon having high mobility as the ink-jet head of the second embodiment is used as the photoresponsive member 37. It is preferable to use a photoresponsive member according to.
[0114]
Further, in the inkjet head 71, the diaphragm 50 of each actuator unit 36 is formed from the flow path substrate 41 made of a silicon substrate. Therefore, by applying a potential to the flow path substrate 41, all the vibration plates 50 are substantially omitted. Since the potential supply line 38 is common to all channels in the common connection portion 38a, all potential supply lines 38 are set to substantially the same potential by applying a potential to the potential supply line 38.
[0115]
First, at time T1, a potential V1 of +20 V is applied to the potential supply line 38 as shown in FIG. 15A, and a potential V2 of 0 V is applied to the diaphragm 50 as shown in FIG. In addition, a potential of −20 V is applied to the potential Vx of the conductive member 34 in an intended state. Therefore, at this time T1, V1 = 20V, V2 = 0V, and Vx = −20V, so | V2−Vx | = 20V.
[0116]
At this time, an electrostatic force is generated between the conductive member 34 and the diaphragm 50 due to the potential difference of 20 V. However, the parameters (thickness, rigidity, etc.) of the diaphragm 50 and the diaphragm 50 and the conductive member 34 By setting the gap length between them, the diaphragm 50 is not significantly deformed and displaced by the electrostatic force due to the potential difference of 20 V (slightly deformed), so that the ink supply to the pressurized liquid chamber 46 is performed. I will not.
[0117]
Here, the light drive signal 40 is in a laser-on state (Leaser on) when scanning the light-responsive member 37 corresponding to the actuator unit 36 (channel) that discharges ink droplets in accordance with the image information, and the ink This signal is a laser off state (Leaser off) when scanning the light response member 37 corresponding to the actuator unit 36 that does not eject droplets.
[0118]
Therefore, in the channel irradiated with the optical drive signal 40, as shown in FIG. 6C, the potential Vx of the conductive member 34 corresponding to the optical response member 37 changes from −20 V to 20 V, and FIG. ), The potential difference | V2−Vx | between the conductive member 34 and the diaphragm 50 decreases from 20V to 0V and returns to 20V in response to light irradiation. At this time, ink is not supplied.
[0119]
On the other hand, in the channel where the optical drive signal 40 is not irradiated, the potential Vx of the conductive member 34 remains Vx = −20 V as shown in FIG. Although the potential difference between the member 34 and the diaphragm 50 is | V2−Vx | = 20 V, as described above, the diaphragm 50 is hardly deformed and displaced, and ink is not supplied.
[0120]
Then, at the time T2 in the figure when scanning of the optical drive signals 40 for all the channels is completed while maintaining the state of the diaphragm 50 corresponding to the optical drive signal 40 for each channel, as shown in FIG. In addition, by setting the potential V2 of the diaphragm 50 to −20V, in the channel irradiated with the light driving signal 40, the potential of the conductive member 34 corresponding to the light response member 37 as shown in FIG. Since Vx is 20 V, the potential difference between the conductive member 34 and the diaphragm 50 becomes | V2−Vx | = 40 V as shown in FIG. All the diaphragms 50 of the actuator portions 36 corresponding to all the light response members 37 irradiated with the optical drive signal 40 and having the light driving signal 40 applied thereto are deformed and displaced toward the conductive member 34 substantially simultaneously, Ink is supplied to the pressurized liquid chamber 46 to respond.
[0121]
After that, when the potential V1 with respect to the potential supply line 38 is set to V1 = −20V at time T3, the pin structure of the photoresponsive member 37 is biased in the forward direction, so that the potential Vx of the conductive member 34 becomes Vx = −20V. Become. As a result, the potential difference between the conductive member 34 and the diaphragm 50 becomes | V2−Vx | = 0 V in all channels, and the deformed diaphragm 50 is restored to the original position, and all the selected channels are selected. Ink droplets are ejected from the nozzle 45.
[0122]
In this way, the potential of the conductive member is made equal to an arbitrary potential of the potential supply line by irradiating the light response member with light as necessary, and a different potential is supplied to the opposing movable member after the light irradiation ends. An arbitrary potential difference is generated between the conductive member and the movable member, and the movable member is displaced or deformed after light irradiation, thereby supplying ink (from the common liquid chamber to the pressurized liquid chamber via the fluid resistance portion). The first operation of the actuator, such as supply of ink, can be performed after light irradiation, and ink supply to the selected actuator can be performed uniformly in the same time after optical scanning of all actuators.
[0123]
Next, a first embodiment of an optical deflection device which is an optical device according to the present invention will be described with reference to FIG. This figure is a cross-sectional explanatory view of the same optical deflection device.
In this optical deflection device, an insulating film 102 is formed on a substrate 101, and a mirror member 103 capable of reflecting light at least on the surface as a movable member is formed on the opening side of a recess formed in the insulating film 102. The mirror member 103 is disposed so as to be displaceable, a conductive member 104 is disposed on the bottom surface of the recess with a predetermined gap 105, and the mirror member 103 and the conductive member 104 constitute an actuator unit 106. .
[0124]
Although the entire movable member is the mirror member 103 here, a configuration in which the mirror member 103 that reflects light only on a part or the surface of the movable member may be provided. Further, a plurality of actuator portions 106 including the mirror member 103 may be arranged one-dimensionally or a plurality of actuator parts 106 may be arranged two-dimensionally.
[0125]
Here, the substrate 101 is a substrate that transmits light, for example, the transparent glass substrate described above, so that the light driving signal 110 can be incident on the inside through the substrate 101 from the outside. The mirror member 103 is preferably made of, for example, an aluminum-based metal or a member in which a dielectric multilayer film or a metal film is formed on the surface of a conductive material in order to increase the reflectance. Here, the conductive member 104 is also formed of a member that transmits light, for example, a transparent member, and has a structure capable of applying an arbitrary potential, and is not electrically floating unlike each of the embodiments of the electrostatic actuator described above. It is configured.
[0126]
Further, a light response member 107 is disposed on the conductive member 104, and a drive unit 109 that drives the actuator unit 106 by the conductive member 104 and the light response member 107 is configured. The light-responsive member 107 is a member that is electrically connected to the conductive member 104 and has a resistance value that varies depending on the presence or absence of light irradiation, the intensity of irradiated light, or the wavelength of irradiated light.
[0127]
The operation of the thus configured optical deflection device will be described. By applying an arbitrary voltage to each of the mirror member 103 and the conductive member 104, a potential difference is generated between the mirror member 103 and the conductive member 104. The electrostatic attractive force acts on the movable member that is also the mirror member 103.
[0128]
At this time, when the optical drive signal 110 is incident on the optical response member 107 through the transparent substrate 101 and the conductive member 104, the resistance of the optical response member 107 is lowered by the generated carriers, and apparently the conductive member 104 and the mirror This means that the distance from the member 103 has been reduced. Then, when the optical drive signal 110 is incident on the optical response member 107, the electrostatic attractive force acting on the mirror member 103 is increased substantially simultaneously, and the movable member that is the mirror member 103 is strongly attracted toward the conductive member 104, and accordingly The reflection direction of the optical information signal 111 is changed and light is deflected.
[0129]
Thus, in order to change the traveling direction of light, at least a part of the movable member has a mirror member, and has a light response member, and at least a part of the light response member faces the movable member. The actuator is configured to control the operation of the actuator unit, that is, the drive by the presence or absence, intensity, or wavelength difference of the light responsive member. There is no need to configure the apparatus, and the optical deflection device can be obtained that has a reduced delay due to the metal wiring, is high-speed, and can be miniaturized at low cost.
[0130]
Next, a second embodiment of an optical deflection device which is an optical device according to the present invention will be described with reference to FIG. The figure is a cross-sectional explanatory view of the optical device.
In this optical deflection device, an insulating film 122 is formed on a substrate 121, and a conductive member 123, a light response member 124, an optical deflection member 125, and a conductive member 123 are formed from the surface side of the substrate 121 in a recess formed in the insulating film 122. The conductive members 126 are sequentially stacked, and the actuator unit 127 and the drive unit 128 are configured by these.
[0131]
Here, the substrate 121 is made of a transparent substrate, for example, the above-described transparent glass substrate, so that the optical driving signal 130 and the optical information signal 131 can be incident on the inside through the substrate 121 from the outside. The conductive members 123 and 126 are formed of a member that transmits light, and have a structure capable of applying an arbitrary potential to the light response member 124 and the light deflection member 125, respectively.
[0132]
The optical information signal 131 uses light having a wavelength that passes through the conductive member 123 and passes through the light response member 124, the light deflection member 125, and the conductive member 126 in the same manner as the light driving signal 130. In this case, the optical information signal 131 and the optical drive signal 130 may be the same light beam, but the wavelengths need to be different.
[0133]
The light response member 124 is a member whose resistance value varies depending on whether or not light is irradiated, the intensity of light to be irradiated, or the wavelength of light to be irradiated, and is formed of a member that transmits light. The light deflection member 124 is a member whose refractive index changes according to voltage, and a member that transmits light, for example, a liquid crystal member is used here.
[0134]
In the optical device configured as described above, by applying an arbitrary voltage to each of the conductive member 123 and the conductive member 126, the light deflection member 125 and the light response member 124 are divided by the resistance. That is, an arbitrary potential difference is generated in the optical deflection member 125, and the optical information signal 131 is changed in an arbitrary direction.
[0135]
At this time, when the optical drive signal 130 is incident on the optical response member 125 through the transparent conductive member 123, the resistance of the optical response member 124 is lowered by the generated carriers, and the voltage acting on the optical deflection member 125 is increased. It will be. As a result, the refractive index of the light deflection member 125 changes almost simultaneously with the irradiation of the light to the light response member 125, and the deflection direction of the optical information signal 131 is changed.
[0136]
Thus, at least a part of the actuator has a light deflecting member whose refractive index changes according to the voltage, and has a light responsive member for driving the actuator, and at least a part of the light responsive member is an actuator. By controlling the operation of the actuator, that is, the drive according to the presence or absence, intensity, or wavelength difference of the light responsive member. Since the optical drive signal can be transmitted with the same light flux after being wavelength-multiplexed with the signal, an optical deflection apparatus that is even faster and smaller than the optical device according to the first embodiment can be obtained.
[0137]
Next, a third embodiment of an optical deflection device that is an optical device according to the present invention will be described with reference to FIG. The figure is a cross-sectional explanatory view of the optical device.
This optical device is a combination of the first embodiment of the electrostatic actuator according to the present invention described above and the first embodiment of the optical deflection device according to the present invention, and an insulating film on the substrate 141. 142, and a mirror member 143 capable of reflecting light at least on the surface, which is a movable member, is disposed displaceably on the opening side of the recess formed in the insulating film 142. The conductive member 144 is disposed on the bottom surface of the recess with the gap 145 interposed therebetween, and the mirror member 143 and the conductive member 144 constitute the actuator unit 146.
[0138]
Note that although the entire movable member is the mirror member 143 here, a configuration in which a mirror member 143 that reflects light only on a part or the surface of the movable member may be provided. In addition, a plurality of actuator portions 146 including the mirror member 143 may be arranged in a one-dimensional manner or in a two-dimensional manner.
[0139]
Here, the substrate 141 is a transparent substrate, for example, the above-described transparent glass substrate, so that the light driving signal 150 can be incident on the inside via the substrate 141 from the outside. The mirror member 143 is preferably made of, for example, an aluminum-based metal or a member in which a dielectric multilayer film or a metal film is formed on the surface of a conductive material in order to increase the reflectance. Here, the conductive member 144 is also formed of a transparent member and has a structure capable of applying an arbitrary electric potential, and has a structure that does not float electrically unlike the above-described electrostatic actuators.
[0140]
In addition, the conductive member 144 is pulled out of the actuator unit 146 to form a lead-out portion 144a. A photoresponsive member 147 is disposed on the lead-out portion 144a, and a potential supply line 148 is connected to the photoresponsive member 147. The conductive member 144, the light response member 147, and the potential supply line 148 constitute a drive unit 149 that drives the actuator unit 146. The light responsive member 147 is a member that is electrically connected to the conductive member 144 and has a resistance value that varies depending on the presence or absence of light irradiation, the intensity of irradiated light, or the wavelength of irradiated light.
[0141]
The operation of the thus configured optical deflecting device will be described. The optical response member 147 is irradiated with the optical drive signal 150 in a state where a predetermined potential is applied to the mirror member 143 and a predetermined potential is applied to the potential supply line 148. Thus, the potential of the conductive member 144 becomes equal to the potential of the potential supply line 148, and a potential difference is generated between the mirror member 143 and the conductive member 144, so that the movable member that is also the mirror member 143 has an electrostatic attractive force. The mirror member 143 is deformed and displaced toward the conductive member 144 side.
[0142]
Thereby, when the optical drive signal 150 is irradiated to the optical response member 147, the reflection direction of the optical information signal 151 incident on the mirror member 143 is changed substantially at the same time, and the light is deflected.
[0143]
In this way, the optical response member is electrically connected to the conductive member of the actuator portion, and the optical response member is further connected to the potential supply line, and the optical response member depends on the optical drive signal incident on the optical response member. By changing the resistance of the conductive member and making the potential of the conductive member the same as the potential of the potential supply line, a stable light deflection operation can be easily performed.
[0144]
Next, a fourth embodiment of an optical deflection device which is an optical device according to the present invention will be described with reference to FIG. The figure is a cross-sectional explanatory view of the optical device. In addition, the same code | symbol is attached | subjected to the part corresponding to 3rd Embodiment.
This optical deflection device is a combination of the first embodiment of the electrostatic actuator according to the present invention described above and the second embodiment of the optical deflection device according to the present invention. A conductive member 144 that transmits light, a light deflecting member 165, and a transparent conductive member 166 are sequentially stacked in the concave portion formed in the film 142, and the actuator portion 167 is configured by these layers. The light deflecting member 165 is the same as the light deflecting member 125 of the second embodiment of the optical device. Others are the same as those in the third embodiment.
[0145]
The operation of the thus configured optical deflection device will be described. By irradiating the optical response member 147 with the optical drive signal 150 in a state where a predetermined potential is applied to the potential supply line 148, the potential of the conductive member 144 is increased. Since the potential between the conductive members 144 and 166 applied to both sides of the light deflection member 165 changes to be equal to the potential of the potential supply line 148, the light response signal 147 is irradiated with the light drive signal 150 substantially at the same time. The reflection direction of the optical information signal 151 incident on the actuator unit 167 changes and is deflected.
[0146]
In this way, by operating the actuator unit almost simultaneously with the irradiation of the optical drive signal corresponding to the optical information, it is possible to perform an optical deflection operation without causing a time delay.
[0147]
Next, another method for driving the optical device will be briefly described. For example, after holding the optical drive information obtained by the irradiation of the optical drive signal for an arbitrary time, the actuator unit (optical deflection unit) may be operated. it can.
[0148]
This can be realized, for example, by driving the optical device according to the third embodiment described with reference to FIG. 18 according to the timing chart described with reference to FIG. That is, the optical scanning time shown in FIG. 14 corresponds to the holding of the optical drive information for an arbitrary time, and the subsequent displacement deformation time corresponds to the operating time of the actuator unit (optical deflecting unit).
[0149]
In addition, after holding the light drive information obtained by light irradiation for an arbitrary time, it is also possible to simultaneously input an arbitrary signal to a plurality of actuator units to operate each actuator unit according to the light drive signal. .
[0150]
For example, in the optical device according to the third embodiment described with reference to FIG. 18, a plurality of actuator portions are provided, and the potentials of the potential supply line 148 of the conductive member 144 and the mirror member 143 are between the plurality of actuator portions 146. This structure can be realized by driving according to the timing chart shown in FIG. That is, the optical scanning time shown in FIG. 14 corresponds to holding an arbitrary time of the optical drive information, and the subsequent displacement deformation time corresponds to the operation time of the plurality of actuator units.
[0151]
Next, an embodiment of an optical transmission apparatus which is an optical device of the present invention will be described with reference to FIG. In addition, the figure is a schematic block diagram of the optical transmission apparatus.
The optical transmission apparatus 201 receives an optical information signal from a plurality of ports 202, determines each optical path, and transmits the optical information signals from a plurality of ports 203. Here, as the optical path switching means 204 for determining the port of the optical information signal to be output by performing optical deflection that changes the traveling direction of the input optical information signal, the optical deflection device that is the optical device according to the present invention described above is provided. ing. As a result, since high-speed light deflection can be performed, the speed of the optical transmission device itself can be increased.
[0152]
In the above-described embodiment, the example in which the ink jet head is applied as a liquid droplet ejection head has been described. However, as a liquid droplet ejection head other than the ink jet head, for example, a liquid droplet ejection head that ejects liquid resist as liquid droplets, DNA The present invention can also be applied to other droplet discharge heads such as a droplet discharge head that discharges the sample as droplets.
[0153]
【The invention's effect】
  As described above, according to the electrostatic actuator according to the present invention,A conductive member made of a light transmissive member is provided on the actuator substrate made of a light transmissive member.An optical response member that responds to light is provided integrally,Light is irradiated through the actuator substrate and the conductive memberVia photoresponsive memberLeadSince the electric member is configured to be supplied with electric potential, high density, large area, and low cost can be achieved..
[0154]
According to the droplet discharge head according to the present invention, the pressurizing means for pressurizing the liquid in the liquid chamber is constituted by the actuator portion of the electrostatic actuator according to the present invention, so that the density is increased, the area is increased, and the cost is reduced. Can be planned.
[0155]
According to the ink jet recording apparatus according to the present invention, the ink jet head for ejecting ink droplets from the nozzles is configured by the liquid droplet ejecting head according to the present invention, and the electrostatic actuator constituting the liquid droplet ejecting head is driven. Therefore, the high-quality image can be recorded at high speed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional explanatory view along the longitudinal direction of a movable member of a first embodiment of an electrostatic actuator according to the present invention.
FIG. 2 is an explanatory plan view of the actuator.
FIG. 3 is an enlarged cross-sectional explanatory view of a main part for explaining a configuration of a light response member of the actuator.
FIG. 4 is an explanatory cross-sectional view along the longitudinal direction of a movable member of a second embodiment of an electrostatic actuator according to the present invention.
FIG. 5 is an explanatory plan view of the actuator.
FIG. 6 is an enlarged cross-sectional explanatory view of a main part for explaining a configuration of a light response member of the actuator.
FIG. 7 is a cross-sectional explanatory view of the first embodiment of the droplet discharge head according to the present invention along the longitudinal direction of the diaphragm.
FIG. 8 is an explanatory plan view of the head.
FIG. 9 is a cross-sectional explanatory view along the longitudinal direction of the diaphragm of the second embodiment of the droplet discharge head according to the present invention.
FIG. 10 is an explanatory plan view of the head.
FIG. 11 is a schematic perspective explanatory view illustrating an embodiment of an ink jet recording apparatus according to the present invention.
FIG. 12 is a schematic side view of the recording apparatus.
FIG. 13 is a schematic configuration diagram of a line-type inkjet head of the recording apparatus.
FIG. 14 is an explanatory diagram for explaining another example of head driving in the recording apparatus.
FIG. 15 is an explanatory diagram for explaining another example of head driving in the recording apparatus.
FIG. 16 is a cross-sectional explanatory view of a first embodiment of an optical deflection device according to the present invention.
FIG. 17 is a cross-sectional explanatory view of a second embodiment of an optical deflection device according to the present invention.
FIG. 18 is a cross-sectional explanatory view of a third embodiment of an optical deflection device according to the present invention.
FIG. 19 is a cross-sectional explanatory view of a fourth embodiment of an optical deflection device according to the present invention.
FIG. 20 is an explanatory cross-sectional view of an embodiment of an optical transmission device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Actuator board | substrate, 3 ... Movable member, 4 ... Conductive member, 7, 17 ... Photoresponsive member, 8 ... Potential supply line, 31 ... Actuator substrate, 34 ... Conductive member, 37 ... Photoresponsive member, 41 ... Current Road substrate, 43 ... Nozzle plate, 44 ... Top plate, 45 ... Nozzle, 46 ... Pressurized liquid chamber, 47 ... Ink supply path (communication part), 48 ... Common liquid chamber, 63 ... Line type inkjet head, 71 ... Inkjet Head, 72 ... Scanning light source system, 103 ... Mirror member, 104 ... Conductive member, 107 ... Optical response member, 124, 127 ... Conductive member, 125 ... Optical response member, 126 ... Optical deflection member, 201 ... Optical transmission device .

Claims (12)

An electrostatic actuator having a movable member and a fixed conductive member opposed to the movable member, and having an actuator unit that deforms or displaces the movable member by electrostatic force by applying a potential to the conductive member In
The conductive member made of a light transmissive member is provided on the actuator substrate made of a light transmissive member, and the light responsive member responsive to light is integrally provided on the conductive member. And an electric potential is applied to the conductive member through the photoresponsive member irradiated with light through the conductive member.   2. The electrostatic actuator according to claim 1, wherein the photoresponsive member is a rectifying photoconductor.   3. The electrostatic actuator according to claim 1, wherein the photoresponsive member is formed of a silicon-based film. In the electrostatic actuator according to any one of claims 1 to 3, comprising a plurality of photoresponsive members corresponding to the actuator unit and the actuator unit, the potential input side of the plurality of photoresponsive members are connected to a common An electrostatic actuator characterized by that. Nozzles for ejecting liquid droplets having a liquid chamber communicating, in a droplet ejection head provided with a pressurizing means for pressurizing the liquid chamber of the liquid, electrostatic according to any one of claims 1 to 4 A droplet discharge head comprising an actuator, wherein the pressurizing means is constituted by an actuator portion of the electrostatic actuator. 6. The droplet discharge head according to claim 5 , wherein the head is a line type head. In the ink jet recording apparatus mounting an ink jet head to eject ink droplets from the nozzles, the ink jet recording apparatus characterized and the liquid droplet ejection head der Turkey according to the ink jet head claim 5 or 6. 8. The ink jet recording apparatus according to claim 7, wherein a light source that emits light in accordance with driving information and a scanning unit that scans the light responsive members of the plurality of actuator units with the light emitted from the light source. An ink jet recording apparatus comprising: 9. The ink jet recording apparatus according to claim 8, wherein light is applied to a light responsive member of an actuator unit of the droplet discharge head to apply a potential to the conductive member, and the light irradiation is performed based on a potential difference from the potential of the movable member. An ink jet recording apparatus characterized in that the movable member is displaced or deformed substantially simultaneously . 9. The ink jet recording apparatus according to claim 8, wherein a light is applied to a light responsive member of an actuator portion of the droplet discharge head to apply a potential to the conductive member, and a predetermined potential is applied to the movable member after the light irradiation. An ink jet recording apparatus, wherein a potential difference is generated between the conductive member and the movable member to displace or deform the movable member after the light irradiation. 11. The ink jet recording apparatus according to claim 9, wherein the potential of the conductive member is reset to an initial potential after the movable member is displaced or deformed. Recording device. 8. The inkjet recording apparatus according to claim 7 , wherein the number of the light sources for one droplet discharge head is one.

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