Fragrance generator

Abstract

To provide a fragrance generator capable of controlling atomization of a trace amount of fragrance ingredients.SOLUTION: A fragrance generator includes a pump part for generating an electroosmotic flow based on a driving voltage, and sending liquid from the upstream side connected to a storage part storing the liquid for generating fragrance to the downstream side, an injection part connected to the downstream side of the pump part, and having an ink-jet element for injecting fine droplets of the liquid based on a control signal, and an atomization part for atomizing injected fine droplets.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a fragrance emitting device that atomizes a liquid to emit a fragrance. [Background technology]

[0002] Research is being conducted into virtual spaces that simulate real spaces. Research is also being conducted into providing olfactory information in virtual spaces in conjunction with images displayed on a display device such as a display that provides visual information. As a technology related to providing olfactory information, for example, the applicant has already proposed a device that atomizes a liquid containing a fragrance component (see, for example, Patent Documents 1 to 3).

[0003] Patent Document 1 describes a fragrance generating device that includes a solenoid valve that ejects a liquid supplied from a container that stores the liquid as a fragrance source, and an atomizer that atomizes the droplets ejected from the solenoid valve. Patent Document 2 describes a fragrance generating device that includes an electroosmotic flow pump that causes the liquid supplied from the container that stores the liquid as a fragrance source to flow, a supply unit that ejects the liquid from an outlet of a flow path provided downstream of the electroosmotic flow pump, and an atomizer that atomizes the droplets ejected from the supply unit. Patent Document 3 describes a fragrance generating device that includes multiple inkjet elements that eject a liquid, and an atomizer that atomizes the ejected liquid using a heater. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-139628 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-184486 [Patent Document 3] Japanese Patent Application Laid-Open No. 2005-249634 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to generate a wider variety of scents, there is a need for technology to control the atomization of minute amounts of scent components and technology to prevent atomized scent components from remaining. However, in the scent generation methods described in Patent Documents 1 to 3, the amount of liquid to be atomized depends on the injection amount based on a solenoid valve, the discharge amount based on an electroosmotic flow pump, or the discharge amount based on an inkjet element, and it is difficult to stably eject even smaller amounts of liquid compared to these injection and discharge amounts. The inventors have continued to conduct extensive research into the atomization of liquids containing scent components.

[0006] An object of the present invention is to provide a fragrance emitting device that can control the atomization of a small amount of fragrance component. [Means for solving the problem]

[0007] One aspect of the present invention is a fragrance generating device that includes a pump unit that generates an electroosmotic flow based on a drive voltage and circulates the liquid from upstream to downstream, connected to a storage unit that stores a fragrant liquid; an ejection unit that is connected downstream of the pump unit and has an inkjet element that ejects microdroplets of the liquid based on a control signal; and an atomization unit that atomizes the ejected microdroplets.

[0008] According to the present invention, the ejection unit has an inkjet element, so that atomization of a minute amount of fragrance component can be controlled based on the ejection unit.

[0009] The present invention may further include a control unit that controls the pump unit in conjunction with the injection unit to adjust the liquid supplied to the upstream side of the injection unit to a predetermined back pressure.

[0010] According to the present invention, since the pump section is provided upstream of the ejection section, the back pressure upstream of the ejection section can be adjusted, and the ejection of minute droplets from the ejection section can be stabilized.

[0011] In addition, the control unit of the present invention may adjust the amount of microdroplets ejected from the inkjet element based on the control signal, and may also control the drive voltage in accordance with the control signal to adjust the flow rate of the liquid supplied to the inkjet element.

[0012] According to the present invention, even if the drive frequency of the ejection unit changes, the pump unit works in conjunction to change the drive voltage, thereby maintaining the back pressure upstream of the ejection unit within an appropriate range and stabilizing the ejection of microdroplets from the ejection unit.

[0013] Furthermore, the atomization part of the present invention may have a SAW device.

[0014] According to the present invention, the atomizing portion generates surface acoustic waves based on a SAW device, so that the liquid ejected from the ejecting portion can be atomized without using heat.

[0015] The present invention may also include a plurality of injection units each having the injection section with the pump section provided on the upstream side, and each injection unit may inject a different type of liquid.

[0016] According to the present invention, it is possible to control the atomization of a liquid containing a plurality of trace amounts of fragrance components. [Effects of the Invention]

[0017] According to the present invention, atomization of a small amount of fragrance component can be controlled. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating a schematic configuration of a fragrance emitting device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional side view schematically illustrating the configuration of a pump section. [Figure 3] FIG. 3 is a cross-sectional side view schematically illustrating the configuration of an injection unit. [Figure 4] FIG. 2 is a plan view schematically illustrating the configuration of the atomizing unit. [Figure 5] FIG. 1 is a block diagram showing the configuration of a fragrance emitting device. [Figure 6] FIG. 10 is a diagram showing the relationship between the drive frequency of the ejection unit and the drive voltage of the pump unit that generates the back pressure required for the ejection unit. [Figure 7] 10A and 10B are diagrams showing the results of a performance test of the fragrance generating device. [Figure 8] 10A and 10B are diagrams showing the results of a performance test of the fragrance generating device. [Figure 9] 10A and 10B are diagrams showing the results of a performance test of the fragrance generating device. [Figure 10] 10A and 10B are diagrams showing the results of a performance test of the fragrance generating device. [Figure 11] 10A and 10B are diagrams showing the results of a performance test of a fragrance emitting device according to a comparative example. [Figure 12] 10A and 10B are diagrams showing the results of a performance test of a fragrance emitting device according to a comparative example. [Figure 13] 10A and 10B are diagrams showing the results of a performance test of a fragrance emitting device according to a comparative example. [Figure 14] 10A and 10B are diagrams showing the results of a performance test of a fragrance emitting device according to a comparative example. [Figure 15] FIG. 10 is a diagram showing the configuration of a fragrance emitting device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0019] As shown in Figure 1, the fragrance generating device 1 is a device for atomizing a liquid Q having a fragrance component to generate a gas containing the fragrance component. The fragrance generating device 1 includes a storage section 20 that stores the fragrance liquid, a pump section 10 provided below the storage section 20, an ejection section 2 provided downstream of the pump section, an atomization section 30 provided below the ejection section, a fan 40 provided adjacent to the atomization section 30, and a control device 50 that controls each device. The storage section 20, pump section 10, and ejection section 2 constitute an ejection unit J.

[0020] The storage unit 20 is a container capable of storing a predetermined amount of liquid Q. The liquid Q is, for example, essential oil containing fragrance components diluted with ethanol. The storage unit 20 is formed in a cylindrical shape. The storage unit 20 is disposed vertically so as to supply the liquid Q to the pump unit 10. An opening 21 is formed on the upper surface of the storage unit 20. A lid may be provided on the opening 21. The storage unit 20 is provided on the lower surface with a bottom 22. An opening (not shown) is formed in the bottom 22 for allowing the liquid Q to flow downstream. The storage unit 20 is a drop-type container that drops the liquid downstream. The upstream side of the pump unit 10 is connected to the opening.

[0021] As shown in FIG. 2, the pump unit 10 is, for example, an electroosmotic flow pump that circulates a liquid Q from an upstream side 10A to a downstream side 10B based on an electroosmotic flow that occurs when a voltage is applied. The pump unit 10 includes, for example, a cylindrical main body 11. An opening is formed on the downstream side of the main body 11 and is connected to the storage unit 20. A discharge port 10C that is connected to the ejection unit 2 is provided on the downstream side of the main body 11. A flow path 12 with a circular cross section is formed inside the main body 11. A cylindrical porous body 13, for example, is inserted in the middle of the flow path 12. The porous body 13 is formed of an insulator such as ceramic. A large number of flow paths are formed in the gaps between the particulate insulator inside the porous body 13.

[0022] A first electrode 15 formed in a disk shape is provided on the upstream side of the porous body 13. The first electrode 15 is connected to the control device 50. The first electrode 15 is, for example, a positive electrode. A second electrode 16 formed in a circular ring shape is provided on the downstream side of the porous body 13. The second electrode 16 is connected to the control device 50. The second electrode 16 is, for example, a negative electrode. The pump unit 10 generates an electroosmotic flow based on a DC driving voltage adjusted to a predetermined voltage, and circulates the liquid Q from the upstream side connected to the storage unit 20 to the downstream side. The flow rate of the liquid Q in the pump unit 10 changes in proportion to the driving voltage. The pump unit 10 is electrically connected to the control device 50. An injection unit 2 is provided on the downstream side of the pump unit 10.

[0023] When liquid Q permeates the gaps in porous body 13, an electric double layer is formed at the interface between porous body 13 and liquid Q. When a positive potential is applied to first electrode 15 and a negative potential is applied to second electrode 16, hydrogen ions at the interface on the liquid Q side forming the electric double layer are attracted toward second electrode 16, which is electrically negative, causing liquid Q to flow from upstream to downstream. The flow resulting from this phenomenon is called electroosmotic flow. Pump unit 10 is compact and can generate electroosmotic flow to move liquid Q at a low flow rate. By using electroosmotic flow, pump unit 10 can move liquid Q at high pressure without pulsation or noise. Pump unit 10 using electroosmotic flow has excellent pressure controllability, making it ideal for introducing liquid into the inkjet element of ejection unit 2. Use of pump unit 10 stabilizes ejection by the inkjet element. Liquid Q flowing within pump unit 10 is supplied to ejection unit 2, which is connected downstream of pump unit 10. In this state, the pump unit 10 generates back pressure on the liquid Q on the upstream side of the injection unit 2.

[0024] As shown in FIG. 3, the ejection unit 2 has, for example, a piezoelectric inkjet element 3. The ejection unit 2 circulates the liquid Q supplied from the pump unit 10 downstream based on, for example, a control signal, and ejects minute droplets of the liquid Q downward from an ejection port 7 at the lower end. The inkjet element 3 has, for example, a cylindrical main body 4. The main body 4 is formed, for example, from a glass pipe. A flow path 5 with a circular cross section is formed inside the main body 4.

[0025] The upstream side of the main body 4 is connected to the discharge port 10C of the pump unit 10 via, for example, a connecting pipe P. A tapered section 6 is formed on the downstream side of the main body 4, the diameter of which decreases towards the tip. An injection port 7 is formed at the tip of the tapered section 6, which penetrates into the flow path 5. The diameter of the injection port 7 is, for example, 60 μm. A piezoelectric element 8 that generates vibrations is provided around the periphery of the main body 4.

[0026] The piezoelectric element 8 includes a first electrode 8A wound around the main body 4, an insulating layer 8C wound around the first electrode 8A, and a second electrode 8B wound around the insulating layer 8C. The first electrode 8A is connected to the control device 50. The first electrode 8A is formed of a metal in a cylindrical shape. The insulating layer 8C is formed of a piezoelectric material such as a ferroelectric ceramic. The second electrode 8B is also formed of a metal in a cylindrical shape.

[0027] By inputting a control signal formed as a pulse wave with a predetermined frequency, a predetermined duty ratio, and a predetermined voltage between the first electrode 8A and the second electrode 8B, the piezoelectric element 8 vibrates in the radial direction, causing vibrations around the main body 4. The inside of the main body 4 is filled with liquid Q. Because the diameter of the main body 4 is formed to be small, for example, about 4 mm, the surface tension and viscosity of the liquid Q come into play, and the liquid Q is retained without leaking out of the injection port 7 when the piezoelectric element 8 is stopped.

[0028] When the piezoelectric element 8 operates and vibrations occur, the back pressure applied to the liquid Q on the upstream side of the main body 4 causes the liquid Q inside the main body 4 to flow from the upstream side to the downstream side. The liquid Q is then ejected from the ejection port 7 as microdroplets. The volume of the microdroplets is, for example, 60 pL to 250 pL. The ejected microdroplets of liquid Q are received on the upper surface of the atomizing unit 30.

[0029] 4, atomization unit 30 is, for example, a SAW device that generates surface acoustic waves (SAW). Atomization unit 30 includes a rectangular plate-shaped piezoelectric substrate 31, an electrode unit 33 formed on piezoelectric substrate 31, and a reflector 35 formed on piezoelectric substrate 31 adjacent to electrode unit 33.

[0030] The piezoelectric substrate 31 is made of a piezoelectric material such as lithium niobate single crystal (LiNbO3). Sound-absorbing materials 31D such as silicone gel or elastic resin may be attached to both ends of the piezoelectric substrate 31, for example, to prevent reflected waves from overlapping when surface acoustic waves are generated, thereby generating standing waves. The sound-absorbing materials 31D do not necessarily have to be provided. An aluminum substrate (not shown), for example, is disposed on the lower surface of the piezoelectric substrate 31. The aluminum substrate dissipates heat generated in the atomization unit 30. Microdroplets of the ejected liquid Q are placed in the atomization region 31R on the upper surface 31c of the piezoelectric substrate 31. The liquid Q contains, for example, an odor component.

[0031] The electrode portion 33 is provided on one end 31a of the piezoelectric substrate 31. The electrode portion 33 has a pair of comb-shaped electrodes 33a and 33b provided on the upper surface 31c. The comb-shaped electrodes 33a and 33b are each formed as a comb-teeth-shaped electrode (Inter Digital Transducer: IDT). The comb-shaped electrodes 33a and 33b are arranged such that a plurality of comb-teeth-shaped electrodes (for example, 21 electrodes) alternately interdigitate with each other.

[0032] When drive power adjusted to a predetermined period, duty ratio, pulse width, and voltage is applied to the pair of comb-shaped electrodes 33a, 33b, a piezoelectric effect occurs, generating a surface acoustic wave W on the piezoelectric substrate 31. The reflecting unit 35 includes multiple parallel electrodes. The reflecting unit 35 reflects the surface acoustic wave W generated by the electrode unit 33. The atomizing unit 30 can move or atomize the liquid Q on the upper surface 31c (mounting surface) by applying drive power having a predetermined period, duty ratio, and pulse width to the electrode unit 33. The minute droplets of liquid Q ejected from the ejecting unit 2 are received on the atomizing unit 30 (see FIG. 1). The distance between the ejecting unit 2 and the atomizing unit 30 is, for example, approximately 10 mm. As the minute droplets of liquid Q continue to be ejected intermittently, they are sequentially atomized on the upper surface 31c of the atomizing unit 30 and dispersed into the atmosphere.

[0033] As shown in FIG. 5, the control device 50 includes a first drive unit 51 that drives the injection unit 2, a second drive unit 52 that drives the pump unit 10, a third drive unit 53 that drives the atomization unit 30, a fourth drive unit 54 that drives the fan 40, a power supply unit 55 that supplies power to each drive unit, and a control unit 56 that controls each drive unit.

[0034] The first drive unit 51 generates a first control signal based on the power supplied from the power supply unit 55 and outputs it to the ejection unit 2. The first control signal is, for example, a pulse voltage adjusted to a predetermined drive frequency and duty ratio. The frequency of the first control signal is adjusted by the control unit 56. The first control signal is set arbitrarily according to the amount of microdroplets of liquid Q ejected from the ejection unit 2.

[0035] The first driving unit 51 includes, for example, an FPGA (Field-Programmable Gate Array) (not shown) that generates a pulse signal of an arbitrary frequency and duty ratio, a voltage conversion unit (not shown) that converts voltage, and a MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) circuit (not shown) that generates a first control signal adjusted to a pulse voltage of an arbitrary frequency and duty ratio based on the voltage and pulse signal supplied from the voltage conversion unit.

[0036] Based on the setting information, the control unit 56 controls the first drive unit 51 to generate a first control signal adjusted to a pulse voltage with a desired frequency and a desired duty ratio. The first drive unit 51 generates a square wave based on the pulse signal output by the signal generator. The emission unit 2 operates intermittently by the square wave output from the first drive unit 51.

[0037] The control unit 56 controls the first drive unit 51 to generate a first control signal, causing the ejection unit 2 to generate vibrations in response to the first control signal, and ejecting minute droplets of liquid Q from the ejection nozzle 7 at the lower end. The control unit 56 adjusts the drive frequency of the first control signal, and adjusts the amount of minute droplets of liquid Q ejected from the ejection nozzle 7 per unit time.

[0038] The second drive unit 52 is controlled by the control unit 56, and generates a second control signal based on the power supplied from the power supply unit 55 and outputs it to the pump unit 10. The second control signal is, for example, a predetermined DC voltage (drive voltage). The voltage value of the second control signal is adjusted by the control unit 56. The control unit 56 controls the second drive unit 52 to generate the second control signal, and causes the pump unit 10 to generate an electroosmotic flow in accordance with the second control signal, causing the liquid Q to flow from the upstream side to the downstream side. The control unit 56 adjusts the voltage of the second control signal to adjust the flow rate per unit time of the liquid Q flowing downstream. The second control signal may be a PWM (Pulse Width Modulation) signal with an adjusted duty ratio.

[0039] In normal use, such as for printing, the inkjet elements of the ejection unit 2 have a fixed driving frequency for the signal input to eject droplets. A drop-type ink tank is provided upstream of the inkjet elements, and a predetermined back pressure of ink (liquid) is applied. Therefore, the inkjet elements are configured to be driven based on signals with a driving frequency within a predetermined range set according to the ink back pressure. If air bubbles are mixed in upstream, the inkjet elements may have difficulty ejecting droplets.

[0040] Therefore, if the inkjet element is operated with a drive frequency signal exceeding a predetermined range of drive frequencies set to increase the amount of droplets ejected from the inkjet element, the back pressure on the upstream side of the inkjet element may decrease, causing air bubbles to be mixed in and making it difficult to eject droplets. Furthermore, if a high back pressure is applied to the upstream side of the inkjet element in advance, liquid may leak from the ejection port of the inkjet element even when the inkjet element is not operating. Furthermore, if the back pressure on the upstream side of the inkjet element is insufficient, air may backflow from the ejection port 7. Since the inkjet element 3 is not provided with a valve, the back pressure of the liquid Q on the upstream side must be appropriately adjusted to stably eject minute droplets from the ejection port 7.

[0041] Therefore, in the fragrance generating device 1, the control unit 56 is configured to control the pump unit 10 in conjunction with the ejection unit 2 to adjust the flow rate so that the liquid Q supplied to the upstream side of the ejection unit 2 has a predetermined back pressure. The control unit 56 adjusts the amount of microdroplets ejected from the inkjet elements of the ejection unit 2 based on an arbitrary first control signal corresponding to the desired amount of droplets of the liquid Q to be ejected, and also controls a second control signal according to the first control signal to adjust the flow rate of the liquid Q supplied to the inkjet elements of the ejection unit 2.

[0042] With the above configuration, the control unit 56 can constantly apply a predetermined range of back pressure to the liquid Q upstream of the inkjet element, preventing a shortage of supply of the liquid Q upstream of the inkjet element and enabling the ejection unit 2 to stably eject minute droplets of the liquid Q.

[0043] The third drive unit 53 is controlled by the control unit 56, and generates a third control signal based on the power supplied from the power supply unit 55, and outputs the third control signal to the atomization unit 30. The third drive unit 53 generates a third control signal based on the power supplied from the power supply unit 55, and outputs the third control signal to the atomization unit 30. The third control signal is, for example, an RF burst voltage (drive power) adjusted to a predetermined drive frequency and duty ratio.

[0044] Third drive unit 53 includes an RF amplifier (not shown) that generates a signal voltage for driving the electrode unit of atomization unit 30, and a signal generator (not shown) that supplies a pulse signal to the RF amplifier (not shown). The RF amplifier amplifies an RF burst signal having a predetermined period and pulse width output from the signal generator, and generates a third control signal (drive power).

[0045] The atomization unit 30 moves and atomizes the liquid Q when provided with driving power by the third drive unit 53. Here, the driving power is, for example, a 10 MHz RF signal generated by a signal generator. The control unit 56 drives the atomization unit 30 in conjunction with the ejection unit 2. For example, the control unit 56 outputs a third control signal simultaneously with the output of the second control signal. For example, after the second control signal is stopped, the control unit 56 continues to output the third control signal for a predetermined time, completely atomizing the liquid Q on the atomization unit 30.

[0046] The fourth drive unit 54 is controlled by the control unit 56 and generates a fourth control signal based on the power supplied from the power supply unit 55, and outputs the fourth control signal to the fan 40. The fourth control signal is, for example, a DC current set to a predetermined voltage value and current value. The fourth drive unit 54 is, for example, a DC stabilized power supply. The control unit 56 drives the fan 40 in conjunction with the operation of the atomization unit 30, thereby diffusing the atomized liquid Q into the atmosphere. The control unit 56 outputs, for example, the fourth control signal simultaneously with the output of the third control signal. For example, after the third control signal is stopped, the control unit 56 continues to output the fourth control signal for a predetermined time, thereby diffusing the atomized liquid Q remaining on the atomization unit 30 into the atmosphere.

[0047] Next, test results regarding the performance of the fragrance emitting device 1 will be described.

[0048] FIG. 6 shows the drive voltage of the pump unit 10 that generates the back pressure required for stable ejection of the liquid Q at the drive frequency of the ejector unit 2. As described above, when a predetermined back pressure is applied upstream of the ejector unit 2, the first control signal of the ejector unit 2 is set to a predetermined drive frequency, and the liquid Q stored in the ejector unit 2 is ejected from the ejection port 7. When the drive frequency is increased to increase the ejection amount of microdroplets of the liquid Q, the pump unit 10 must adjust the back pressure in conjunction with the ejector unit 2 to increase the flow rate of the liquid Q so that the back pressure of the ejector unit 2 is not insufficient. Furthermore, the pump unit 10 must adjust the back pressure in conjunction with the ejector unit 2 so that the back pressure of the ejector unit 2 is not excessive. The control unit 56 increases the drive voltage within an appropriate range in response to an increase in the drive frequency.

[0049] As shown in the figure, a driving voltage of the pump unit 10 was tested to confirm that the liquid Q supplied to the upstream side of the ejection unit 2 is at a predetermined back pressure relative to the driving frequency of the ejection unit 2. By adjusting the driving voltage of the pump unit 10 relative to the driving frequency of the ejection unit 2 within the range shown in the figure, the fragrance generating device 1 can apply a back pressure that allows the ejection unit 2 to stably eject the liquid Q.

[0050] Figures 7 to 10 show the results of a performance test of the fragrance generator 1. In the performance test, the fragrance generator 1 operated the emission unit 2 at various drive frequencies (1 Hz, 10 Hz, 100 Hz, 500 Hz) for a predetermined time (e.g., 30 seconds) to emit ethanol. As shown in the figures, in terms of the relationship between the concentration of the generated gas and the time the gas remains, it can be seen that the minute droplets of ethanol emitted by the fragrance generator 1 were all atomized and did not remain after approximately 30 seconds after emission, even when the drive frequency was increased.

[0051] 11 to 14 show the results of a performance test of a comparative fragrance generator having a solenoid valve with an electroosmotic pump installed upstream. In the performance test, the fragrance generator of the comparative example operated the solenoid valve at various drive frequencies (100 Hz, 200 Hz, 300 Hz, and 500 Hz) for a predetermined time (e.g., 30 seconds) to inject ethanol. As shown in the figures, in terms of the relationship between the concentration of the generated gas and the time the gas remained, the ethanol microdroplets injected by the fragrance generator of the comparative example were completely atomized without remaining for more than 30 seconds after injection at drive frequencies of 100 Hz and 200 Hz. However, when the drive frequency was increased to 300 Hz and 500 Hz, the time of residence increased to 90 seconds and 110 seconds, respectively.

[0052] The control unit 56 described above is realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (not shown) such as an HDD (Hard Disk Drive) or flash memory, or may be stored on a removable storage medium such as a DVD or CD-ROM and installed by inserting the storage medium into a drive device. Furthermore, a program is not necessarily required; a predetermined operation may be performed by configuring a sequential circuit in the control unit 56.

[0053] As described above, in the fragrance generating device 1, the ejection unit 2 has an inkjet element, which reduces the minimum value of the dynamic range of the ejection unit 2 that ejects microdroplets of liquid Q, making it possible to more precisely adjust the concentration of liquid Q. In the fragrance generating device 1, the pump unit 10 is provided upstream of the ejection unit 2, which makes it possible to adjust the back pressure upstream of the ejection unit 2 and stabilize the ejection of microdroplets from the ejection unit 2. In the fragrance generating device 1, even if the drive frequency of the ejection unit 2 changes, the pump unit 10 changes the drive voltage in conjunction with the ejection unit 2, making it possible to maintain the back pressure upstream of the ejection unit 2 within an appropriate range.

[0054] [Variations] Modified examples of the fragrance emitting device 1A will be described below. In the following description, the same components as those in the above embodiment will be designated by the same names and reference numerals, and duplicated descriptions will be omitted as appropriate.

[0055] As shown in FIG. 15, the fragrance generating device 1A may include multiple ejection units J, each having an ejection section 2 with a pump section 10. Each ejection unit J may be provided for a different type of liquid Q. The control section 56 may individually control each ejection unit J to emit a different type of fragrance. The control section 56 may individually control the ejection section 2 and the pump section 10 in one or more ejection units J to mix different types of liquid Q in the atomization section 30 and atomize a fragrance with adjusted components.

[0056] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0057] DESCRIPTION OF SYMBOLS 1, 1A...fragrance generating device, 2...ejection unit, 3...inkjet element, 4...main body, 5...flow path, 6...tapered portion, 7...ejection port, 8...piezo element, 8A...first electrode, 8B...second electrode, 8C...insulating layer, 10...pump unit, 10C...discharge port, 11...main body, 12...flow path, 13...porous body, 15...first electrode, 16...second electrode, 20...storage unit, 21...opening, 22...bottom unit, 30... atomization unit, 31... piezoelectric substrate, 31D... sound absorbing material, 31R... atomization region, 33... electrode unit, 33a, 33b... comb-shaped electrodes, 35... reflection unit, 40... fan, 50... control device, 51... first drive unit, 52... second drive unit, 53... third drive unit, 54... fourth drive unit, 55... power supply unit, 56... control unit, J... injection unit, P... connecting pipe, Q... liquid, W... surface acoustic wave

Claims

1. a pump unit that generates an electroosmotic flow based on a driving voltage and distributes the liquid from an upstream side to a downstream side connected to a storage unit that stores a liquid having a fragrance; an ejection unit having an inkjet element connected to the downstream side of the pump unit and ejecting minute droplets of the liquid based on a control signal; an atomization unit that atomizes the ejected microdroplets; a control unit that controls the drive voltage based on the control signal to adjust the liquid supplied to the upstream side of the ejection unit to a predetermined back pressure; A fragrance generating device comprising:

2. The fragrance emitting device according to claim 1, wherein the control unit adjusts the amount of the micro droplets ejected from the inkjet element based on the control signal, and controls the drive voltage in accordance with the control signal to adjust the flow rate of the liquid supplied to the inkjet element.

3. The atomization unit has a SAW device. The fragrance generating device according to claim 1 or 2.

4. a plurality of injection units each having the injection section with the pump section provided on the upstream side; The fragrance emitting device according to claim 1 , wherein each of the injection units injects a different type of liquid.

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