JP2015034706A - Liquid amount display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid amount display device which facilitates confirmation of liquid amount and displays information about liquid amount.SOLUTION: The liquid amount display device comprises: a light source 40 for radiating light in predetermined wavelength to inside of a liquid amount display pipe 20 communicating with a container 10; a light reception part 50 for outputting a light reception signal according to a light reception state; and a processing part 60 for processing the light reception signal. A float 30 including at least one kind of a luminous body for radiating visible light according to the incident light derived from the light source 40, and being formed of materials floating on a surface of liquid W, is stored in the liquid amount display pipe 20.

Description

  The present invention relates to a liquid amount display device.

  2. Description of the Related Art Conventionally, a liquid amount display device is known in which the amount of liquid contained in a predetermined container or the like can be easily visually recognized even in a dark environment. For example, in Patent Document 1, a liquid amount display tube for confirming the liquid amount, a solid light source that emits excitation light provided on one side of the liquid amount display tube, and a liquid amount display tube are provided. There has been proposed a liquid amount display device including a phosphor that emits fluorescence when excited by excitation light from the individual light source and includes a phosphor float that floats on the surface of the liquid.

  According to the liquid amount display device described in Patent Document 1, fluorescence is emitted from the phosphor float floating on the surface of the liquid when the phosphor is excited by excitation light from a solid light source. By visually recognizing this fluorescence, the user can easily confirm the position of the liquid surface of the liquid amount display device, and hence the liquid amount.

JP 2013-63167 A

  However, in the technique of Patent Document 1, although the user can easily confirm the liquid amount, information on the liquid amount cannot be obtained on the liquid amount display device side. For this reason, for example, when the amount of liquid decreases, a process that can be performed by obtaining information on the amount of liquid, such as requesting the user to supply water or performing an airing prevention process, has not been performed.

  In view of such a problem, an object of the present invention is to provide a liquid amount display device that not only facilitates confirmation of a liquid amount but also can present information related to the liquid amount.

  The liquid amount display device of the present invention includes a liquid amount display tube that communicates with the inside of a container that stores liquid and extends in a vertical direction, and a predetermined amount from one end side of the liquid amount display tube toward the inside of the liquid amount display tube. A light source that emits light of a wavelength; a light receiving unit that is disposed on the other end side of the liquid amount display tube and that outputs a light receiving signal according to a light receiving state; and a processing unit that processes the light receiving signal; A float formed of a material that contains at least one kind of light body that emits visible light in response to incident light derived from the light source and floats on the surface of the liquid is housed inside the display tube. And

  The light body used in the present invention includes a solid material such as a fluorescent pigment or a phosphor that emits fluorescence according to incident light, a liquid material such as a fluorescent paint that emits fluorescence according to incident light, and light such as a mirror surface. A reflector is included.

  According to the liquid amount display device of the present invention, since the float light body accommodated in the liquid amount display tube emits visible light according to the incident light derived from the light source, the user can display the liquid even in a dark environment. The amount can be easily confirmed.

  In addition, the closer the float is to the light receiving unit, the higher the intensity of light derived from the light body that can be received by the light receiving unit, while the farther the float is from the light receiving unit, the farther the float is from the light body that can be received by the light receiving unit. The light intensity is low. Since the distance between the float floating on the liquid surface and the light receiving unit installed on the other end of the liquid level display device corresponds to the amount of liquid, the light reception signal output from the light receiving unit is the light from the float. Information on the strength of the liquid, that is, the liquid amount. By processing this light reception signal by the processing unit, it is possible to present information relating to the liquid amount, such as storing the information relating to the liquid amount in the apparatus or transmitting the information to an external device.

  The liquid amount display tube may be disposed inside the container. At this time, the inner tube and the outer tube are formed in a double tube structure in which the inner tube and the outer tube are arranged apart from each other, and the light source is installed below the liquid amount display tube and is directed toward the inner tube. It is preferable to irradiate the light.

  According to this configuration, the inner tube and the outer tube are spaced apart from each other, so that air having a lower refractive index than the liquid is interposed between the inner tube and the outer tube. Because of the refractive index of the inner tube and air, light derived from the light source is totally reflected in the inner tube, so that the inside of the liquid amount display tube is efficiently guided. As a result, since the rate of reaching the light float derived from the light source increases, the intensity of the visible light emitted by the light body according to the incident light increases. Along with this, information on the liquid amount is more easily reflected in the light receiving unit in the light receiving state of the light derived from the light body in the float that can be received by the light receiving unit.

  In the liquid amount display device according to the aspect of the invention, it is preferable that the light receiving unit includes an optical filter that cuts incident light derived from the light source. According to this, since the light receiving unit can receive the light derived from the light body in the float while reducing the influence of the incident light derived from the light source, the distance between the float and the light receiving unit depends on the light reception state in the light receiving unit. It becomes easy to be reflected.

  In the liquid level display device according to the present invention, the float may be the first phosphor that has a fluorescence intensity maintenance rate of a predetermined ratio or more when the float rises from a predetermined first temperature to a predetermined second temperature. It is preferable that at least one second phosphor having a fluorescence intensity maintenance rate when the temperature rises from the first temperature to the second temperature is less than the predetermined ratio is included.

  According to this configuration, when the temperature of the liquid stored in the container rises from the first temperature to the second temperature, the fluorescence of the first phosphor is higher than when the temperature of the liquid is the first temperature. The intensity is relatively higher than the fluorescence intensity of the second phosphor. As a result, since the light emission mode of the float changes according to the temperature, the user can easily grasp the temperature of the liquid stored in the container by looking at the float.

  In the liquid amount display device of the present invention, a light guide lens for branching and guiding excitation light from the light source is provided, and the light guide lens is configured such that part of the excitation light emitted from the light source causes the float to be in the liquid amount. The light source is irradiated from one side of the display tube and the other part of the excitation light emitted from the light source irradiates the float from the side opposite to the one side of the liquid volume display tube. The excitation light branching unit divides and guides the excitation light from the light source, and the light guide lens irradiates a part of the excitation light emitted from the light source from the one side of the liquid display tube to the float An excitation light guide that guides the remaining part of the excitation light emitted from the light source to a side opposite to the one side of the liquid amount display tube; and The excitation light guided to the side opposite to the one side is caused to transmit the one of the liquid display tubes to the float. It is preferable that the side of and a pumping light folding unit folding to illuminate from the opposite side.

  According to these liquid quantity display devices, even when the light source is provided only on one side of the liquid quantity display tube, the float is connected to the liquid quantity display pipe from one side of the liquid quantity display tube. By irradiating from both sides, that is, the side opposite to one side, the entire surface of the float can be made to emit light. Along with this, information on the liquid amount is more easily reflected in the light receiving unit in the light receiving state of the light derived from the light body in the float that can be received by the light receiving unit.

  In the liquid amount display device according to the aspect of the invention, the processing unit stops the processing for stopping the irradiation of the light source, the processing for adjusting the irradiation interval of the light source, the processing for issuing an alarm, and the processing for the liquid contained in the container. It is preferable to perform at least one of the processes to be performed.

  According to the liquid amount display device having such a configuration, the processing unit performs appropriate processing in accordance with the light reception signal indicating the light reception state in which the liquid amount is reflected, and thus information regarding the liquid amount can be appropriately utilized.

1A and 1B are diagrams illustrating a liquid amount display device according to a first embodiment, in which FIG. 1A illustrates a liquid amount display device when a certain amount of liquid W exists, and FIG. 2B illustrates a liquid amount display device during drought. The figure which shows the structure of the stopper. The figure which shows the circuit structure of the liquid quantity display apparatus of 1st Embodiment. The graph which shows the relationship between a liquid amount and the detection voltage in the resistance 61. FIG. It is a figure which shows the structure of the float 30, (a) shows an example of a structure of the float 30, (b) shows an example of a structure of the float 30 when the weight 33b is attached inside. It is a figure which shows the structure of the liquid quantity display apparatus of 2nd Embodiment, (a) is a perspective view of a liquid quantity display apparatus, (b) is a cross section along the AA line of (a), and is radiate | emitted from the light source 40. Shows the optical path of the light. The perspective view of the liquid amount display apparatus of 3rd Embodiment. It is a figure which shows the structure of the liquid quantity display apparatus of 3rd Embodiment, (a) is a front view, (b) is sectional drawing which follows the BB line of (a). It is a figure which shows the optical path of the light radiate | emitted from the light source 140 in 3rd Embodiment, (a) is when the liquid level display tube 120 is a single tube structure, (b) is the liquid level display tube 120 having a double structure. Indicates a case.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Fig.1 (a) is a figure which shows the example of 1 structure of the liquid quantity display apparatus of this invention. Referring to FIG. 1 (a), a liquid amount display device of the present invention communicates with a container 10 containing a liquid (for example, water) W via a communication pipe 11 and has a liquid having an inner diameter d1 extending in the vertical direction. The amount display tube 20 is disposed below the liquid amount display tube 20 and emits light having a predetermined wavelength in the wavelength region from ultraviolet light to green visible light toward the inside of the liquid amount display tube 20. And a light source 40.

  The liquid amount display tube 20 includes at least one kind of phosphor that floats on the surface (liquid surface) of the liquid W and is excited by excitation light from the light source 40 and emits fluorescence having a longer wavelength than the emission wavelength of the light source 40. A float 30 having an outer diameter d2 (d2 <d1) is provided.

  The liquid level display device includes a light receiving unit 50 disposed at the upper end of the liquid level display tube 20 and a processing unit 60 connected to the light receiving unit 50.

  The communication tube 11 is formed of a material (transparent material) that transmits the excitation light from the light source 40 toward the float 30 in the liquid amount display tube 20 in a portion irradiated with the excitation light from the light source 40. . The liquid amount display tube 20 is made of a transparent material so that at least a part thereof is visible from the outside.

  Further, as shown in FIG. 1A, the liquid level display tube 20 is provided with a float 30 in the liquid level display tube 20 without disturbing the communication of the liquid W between the liquid level display tube 20 and the container 10. A stopper 21 is provided for holding it inside. Specifically, the stopper 21 is formed of a material that does not transmit light below the liquid amount display tube 20.

  As shown in FIG. 2, the stopper 21 includes a hemispherical cut that can accommodate the float 30, and a through hole 22 having an inner diameter d <b> 3 (d <b> 3 <d <b> 2) at the lower end of the cut.

  As shown in FIG. 1 (b), the float 30 fits in the notch of the stopper 21 during drought, so that the float 30 does not flow out of the liquid amount display tube 20.

  When the float 30 fits in the notch of the stopper 21, light derived from the light source does not reach directly above the float 30. For this reason, only the light derived from the phosphor inside the float 30 reaches the light receiver 50. However, since the float 30 is in the same position unless liquid is supplied, the amount of light received by the light receiver 50 is substantially constant.

  Instead of the stopper 21, a member for preventing the float 30 from flowing out into the container 10, for example, a mesh-like wire mesh may be employed. In this case, the roughness of the mesh is smaller (fine) than the outer diameter d2 of the float 30. However, in the example of FIG. 1A, the optical path from the light source 40 to the float 30 is prevented as much as possible. It is preferred that there is no roughness. Moreover, this stopper 21 may be formed with the material (transparent material) which permeate | transmits the excitation light from the light source 40, for example.

  The float 30 is formed of a resin kneaded with a phosphor, and the specific gravity is adjusted so as to float on the surface (liquid level) of the liquid W in the liquid amount display tube 20. As a material used for the float 30, a material having a specific gravity smaller than the specific gravity of the liquid W (1 when the liquid W is water) may be selected. A cavity having a volume may be provided and designed to float on the surface (liquid level) of the liquid W.

  The float 30 is not necessarily spherical, and may have a conical shape, a cylindrical shape, a polygonal shape, or the like. Further, when the float 30 is spherical, its outer diameter d2 needs to be smaller than the inner diameter d1 of the liquid amount display tube 20.

  In addition, when the liquid level display device of the present invention is used in a device that contains a high-temperature liquid such as an electric water heater or a heat-retaining container, the float 30 is required not to deteriorate in a high-temperature liquid (for example, in hot water). . In this case, a material having high heat resistance is suitable for the material of the float 30 in which the phosphor is dispersed. For example, when the liquid is water, the float 30 is preferably formed using a material having high heat resistance that does not deteriorate at 150 ° C. or higher. Specifically, the material of the float 30 in which the phosphor is dispersed is preferable because materials such as epoxy resin, fluororesin, phenol resin, and silicone resin do not deteriorate even at 150 ° C. or higher.

In addition, as the material of the float 30, a material in which the phosphor powder having the above-described composition is dispersed in glass containing components such as SiO ₂ , B ₂ O ₃ , Al ₂ O ₃ can be used. Examples of glass phosphors in which a luminescent center ion is added to a glass matrix include Ca—Si—Al—O—N and Y—Si—Al—O—N systems in which Ce ³⁺ or Eu ²⁺ is added as an activator. An oxynitride glass phosphor may be used. Further, phosphor ceramics may be used for the float 30.

  As shown in FIG. 3, the light source 40 includes a light emitter 41 and a resistor 42. As the light emitter 41, a light emitting diode or a semiconductor laser having a light emission wavelength from ultraviolet light to green visible light can be employed.

More specifically, the light emitting device 41 may be, for example, a light emitting diode or a semiconductor laser that emits near ultraviolet light having an emission wavelength of about 380 nm to about 405 nm using an InGaN-based material. In this case, the phosphor included in the float 30 is excited by ultraviolet light having a wavelength of about 380 nm to about 405 nm.
The red phosphor includes CaAlSiN ₃ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ⁴⁺ etc. are used,
For the yellow phosphor, (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^{2+ and the} like are used.
The green phosphor includes (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ^{2+ and the} like are used, and BaMgAl ₁₀ O ₁₇ : Eu ^{2+ and the} like are used as the blue phosphor.

The light emitter 41 may be, for example, a light emitting diode or a semiconductor laser that emits blue light having a light emission wavelength of about 460 nm using a GaN-based material. In this case, the phosphor contained in the float 30 is assumed to be excited by blue light having a wavelength of about 440 nm to about 470 nm, for example,
The red phosphor includes CaAlSiN ₃ : Eu ²⁺ , (Ca, Sr) AlSiN ₃ : Eu ²⁺ , Ca ₂ Si ₅ N ₈ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , KSiF ₆ : Mn ⁴⁺ , KTiF ₆ : Mn ⁴⁺ etc. are used,
For the yellow phosphor, Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ , Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu ^{2+ and the} like are used.
The green phosphor includes Lu ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Lu, Y) ₃ Al ₅ O ₁₂ : Ce ³⁺ , Y ₃ (Ga, Al) ₅ O ₁₂ : Ce ³⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , CaSc ₂ O ₄ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ , (Si, Al) ₆ (O, N) ₈ : Eu ²⁺ or the like is used.

  The light receiving unit 50 includes a light receiver 51 and a case 52 that houses the light receiver 51.

  The light receiver 51 is made of a photodiode, and is housed in a case 52 installed at the upper end of the liquid amount display tube 20 as shown in FIG. 1A, and is light derived from a phosphor contained in the float 30. Is placed downward (inside the liquid amount display tube 20) so that the light can be received through the case 52.

  The case 52 is made of, for example, a transparent material so as to transmit light derived from the phosphor. The case 52 may be configured to block light (for example, light derived from the light source 40) other than the phosphor included in the float 30 by including an optical filter (high-pass filter).

  The processing unit 60 is electrically connected to the light receiver 51 of the light receiving unit 50, and is configured to perform processing according to the amount of light received by the light receiver 51 (a received light signal indicating the received light amount). Specifically, as shown in FIG. 3, the processing unit 60 includes the resistor 61 and the detection circuit 62 connected in parallel, and is connected in series with the light receiver 51. A series circuit of the light receiver 51 and the processing unit 60 is connected in parallel with the light source 40. Electric power is supplied to the light emitter 41 and the light receiver 51 from a power source 23 such as a battery via a power switch 24. The power supply 23 is turned on or off when the power switch 24 is turned on or off.

  According to the circuit configuration of FIG. 3, the light emitted from the light emitter 41 excites the phosphor of the float 30 in the liquid amount display tube 20 to emit light, and the light reaches the light receiver 51. As a result, a current corresponding to the amount of light received by the light receiver 51 is generated and flows through the resistor 61, thereby generating a potential difference between both ends of the resistor 61. By detecting this potential difference with the detection circuit 62, processing according to the light receiving state of the light receiver 51, that is, the amount of the liquid W can be performed.

  The processing unit 60 outputs the output signal according to the light reception status (voltage generated in the resistor 61) of the light receiving unit 50 to the outside, the processing for storing the output signal in the memory, and the light reception status of the light receiving unit 50 as the liquid amount. It may be configured to perform a process of converting into a signal indicating. The processing unit 60 also stops the processing for the liquid stored in the container (for example, the container 10) when the light receiving state of the light receiving unit 50 indicates that the liquid amount is equal to or less than a predetermined liquid amount. Processing for outputting a heating stop signal for the container 10 to the heater), processing for issuing an alarm such as a notification that the amount of liquid is low, and processing for stopping the light emission of the light source 40 until liquid is supplied. May be.

  Further, when the processing unit 60 indicates that the light receiving state of the light receiving unit 50 indicates that the liquid amount is equal to or less than a predetermined liquid amount (for example, the float 30 is closing the through hole 22 of the stopper 21), The light source 40 may be configured to blink at regular intervals (for example, 2 seconds on, 3 seconds off). By doing in this way, the electric power used for the light source 40 can be saved.

  In the liquid amount display device having such a configuration, the excitation light from the light source 40 that is spatially separated from the float 30 that floats on the surface (liquid surface) of the liquid W in the liquid amount display tube 20. When irradiated, the phosphor contained in the float 30 is excited by the excitation light from the light source 40 to emit light (fluoresce). Due to the light emitted from the float 30, the user can easily visually recognize the position WL of the surface (liquid level) of the liquid W (and therefore the liquid amount) in the liquid amount display tube 20 even in a dark environment.

  For example, when the entire surface of the spherical float 30 is covered with a uniform material (a material in which phosphors are dispersed), in the example of FIG. 1A, the excitation light from the light source 40 is, for example, a spherical shape. Only the lower half of the outer surface of the float 30 is irradiated, and only the lower half of the outer surface of the float 30 emits fluorescence.

  In order to obtain uniform fluorescence emission from the entire surface of the float 30, the float 30 desirably absorbs light from the light source 40 and emits light uniformly. For this purpose, as a structure of the float 30, for example, as shown in a sectional view in FIG. 5A, a cavity portion 32 is provided inside the float 30, and the light source 40 is provided in the cavity portion 32 of the float 30. An excitation light introducing part (optical part) 33a for introducing the excitation light can be provided.

  In the example of FIG. 5A, the excitation light introducing unit (optical part) 33a has a function of moving the center of gravity of the float 30 toward the excitation light introducing unit 33a (the excitation light introducing unit 33a is always provided below the float 30). In this way, the excitation light from the light source 40 can be introduced into the cavity 32 of the float 30.

  In the example of FIG. 5A, the excitation light introducing unit 33 a has a function of moving the center of gravity of the float 30 toward the excitation light introducing unit 33 a (make sure that the excitation light introducing unit 33 a comes below the float 30. 5) (cross-sectional view), for example, a weight 33b is provided inside the float 30 and the center of gravity of the float 30 is placed on the weight 33b. A function of moving to the 33a side (a function of ensuring that the excitation light introducing portion 33a always comes to the lower part of the float 30) can also be provided.

  Thus, by providing the cavity portion 32 inside the float 30 and providing the excitation light introducing portion 33a for introducing the excitation light from the light source 40 into the cavity portion 32 of the float 30, the entire interior surface of the float 30 is provided. The excitation light can be irradiated almost uniformly, and the entire surface of the float 30 can be made to emit fluorescent light almost uniformly, so that the visibility is further enhanced. Further, the amount of light received from the float 30 received by the light receiving unit 50 increases.

  As described above, the float 30 is, for example, a spherical one having a cavity in which phosphor particles are dispersed in a transparent resin, and an excitation light introducing portion (optical portion) 33a for introducing excitation light. What it has can be used.

  Further, as the float 30, for example, a spherical one made of phosphor glass having a hollow inside and having an excitation light introduction part (optical part) 33 a for introducing excitation light is used. be able to.

  Further, as the float 30, for example, a spherical one made of phosphor ceramics having a cavity inside and having an excitation light introduction part (optical part) 33 a for introducing excitation light is used. be able to.

  Instead of or in addition to the phosphor contained in the float 30, a light body such as a light reflector such as a mirror may be used.

  By the way, the above-described float 30 can include only a single phosphor, but a plurality of phosphors having different temperature characteristics can be combined. In this case, the temperature of the liquid W ( The emission color of the float 30 can be changed according to the temperature of the liquid W in the container 10, and thus the temperature of the liquid W can be easily known.

  That is, in general, a phosphor has a characteristic that the fluorescence conversion efficiency decreases as the ambient temperature rises. This is called temperature quenching. The temperature quenching characteristics of the phosphor can be controlled by the host material of the phosphor, the element at the emission center, the density of crystal defects, and the like.

As an example, in the case of a red light emitting CaAlSiN ₃ : Eu ²⁺ phosphor, for example, the fluorescence intensity maintenance rate (the fluorescence intensity at 25 ° C. is assumed to be 100) when the ambient temperature is increased from room temperature to 100 ° C. is representative. Is about 97% (temperature quenching rate is about 3%). On the other hand, for example, in the case of the yellow phosphor (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ phosphor, the fluorescence intensity maintenance rate when the ambient temperature changes from room temperature to 100 ° C. (the fluorescence intensity at 25 ° C. is 100). Is typically about 89% or less (temperature quenching rate is about 11% or more). When these two types of phosphors were blended with CaAlSiN ₃ : Eu ²⁺ phosphors: (Sr, Ba) ₂ SiO ₄ : Eu ²⁺ phosphors = 4: 1 and mixed in a silicone resin at a weight ratio of 5 wt%, Although the fluorescence chromaticity at 100 is orange, the fluorescence chromaticity at 100 ° C. is red, and the temperature (for example, hot water) of the liquid (for example, water) W can be recognized by the fluorescence emission color of the float 30.

  As described above, the above-described float 30 can include a single phosphor, but a plurality of phosphors having different temperature characteristics can be combined. In this case, the temperature of the liquid W The emission color of the float 30 can be changed according to (the temperature of the liquid W in the container), whereby the temperature of the liquid W can be easily known.

  As described in Patent Document 1, the float 30 includes at least one phosphor having a fluorescence intensity maintenance rate of 90% or more when the temperature is increased from room temperature to 90 ° C., and the temperature is increased from room temperature to 90 ° C. When at least one type of phosphor having a fluorescence intensity maintenance rate of less than 90% is included when the temperature rises, the emission color of the float 30 is changed according to the temperature of the liquid W (the temperature of the liquid W in the container). be able to. Thereby, the temperature (for example, hot water temperature) of the liquid (for example, water) W can be easily known.

  FIG. 4 is a graph when the relationship between the liquid amount L and the voltage V generated by the resistor 61 is experimentally measured using the circuit shown in FIG. 3 in the present embodiment. While changing the liquid volume L, the voltage V at the resistor 61 was measured for each predetermined liquid volume (200 ml). A dotted line shows a graph at the time of the first measurement, and a solid line shows a graph at the time of the second measurement.

  As shown in FIG. 4, during drought, that is, when the liquid volume L is 0 or close to 0, the voltage V at the resistor 61 is close to 0V. On the other hand, as the liquid volume L increases, the voltage V at the resistor 61 increases. However, when the liquid volume L exceeds a certain liquid volume, the voltage V starts to decrease and then increases again after a while. It is assumed that the reason for once falling is that the light from the light source 40 is affected.

  The change in the graph is slightly different between the first measurement and the second measurement. This is because the light reception status of the light receiving unit 50 affects not only the light from the light source 40 but also the ambient light status. It is presumed that they have received it.

  As can be seen from this graph, the voltage of the resistor 61 decreases when the liquid amount L is close to 0, and increases when the liquid amount L is medium or higher. Therefore, it is determined whether or not the liquid volume L is equal to or less than a predetermined liquid volume (for example, L1) depending on whether or not the voltage of the resistor 61 exceeds a certain threshold (for example, voltage V1 in the graph). Can do.

  Since the reception signal from the light receiving unit varies depending on the diameter and shape of the float 30 or the inner diameter of the liquid amount display tube 20 and the emission energy of the light source 40, the threshold value is preferably determined in advance by, for example, experiments.

  Since the voltage at the resistor 61 does not simply increase as the liquid amount L increases, the liquid amount L cannot be uniquely determined from the voltage. However, for example, by recording the change in the liquid amount L, it is possible to estimate the approximate amount of the liquid amount L from the change mode of the liquid amount L that appears in the recording.

(Second Embodiment)
In order to obtain fluorescence emission from the entire surface of the float 30, as described in JP 2013-108888 A, the float 30 is placed on one side of the liquid amount display tube 20 (for example, a liquid amount display). It is desirable to illuminate not only with excitation light from the lower side of the tube 20 but also with excitation light from the side opposite to one side of the liquid level display tube 20 (for example, the upper side of the liquid level display tube 20). . In this specification, the outline of irradiation from both sides of the float 30 will be briefly described below.

  FIG. 6 (a) shows that the float 30 is connected to one side (for example, the liquid level display tube 20) only by the light source 40 on one side (for example, the lower side of the liquid level display tube 20). Illumination is performed not only by excitation light from the lower side of the liquid volume display tube 20 but also by excitation light from the side opposite to one side of the liquid volume display tube 20 (for example, the upper side of the liquid volume display tube 20). It is a figure which shows the structural example of an optical system.

  In FIG. 6A, a liquid amount display tube 20 including the communication tube 11 and a float 30 (not shown) arranged in the liquid amount display tube 20 are arranged on one side of the liquid amount display tube 20 (for example, In addition to excitation light from the lower side of the liquid level display tube 20, illumination is also performed by excitation light from the side opposite to one side of the liquid level display tube 20 (for example, the upper side of the liquid level display tube 20). An optical system composed of a light guide lens 70 is shown. In general, the liquid amount display tube 20 is observed from the surface opposite to the side to which the communication tube 11 is connected.

  Referring to FIG. 6B, the light guide lens 70 branches and guides the excitation light from the light source 40 and is disposed so as to surround the liquid amount display tube 20. However, the light guide lens 70 is provided with a communication tube 11 that communicates the container 10 and the liquid amount display tube 20 with a range that does not obstruct liquid amount observation from a liquid amount observation window provided in an external housing (not shown). Opening portions 71a and 71b are provided in a range not hindering, respectively.

  More specifically, in the light guide lens 70, a part BM1 of the excitation light from the light source 40 irradiates the float 30 from one side of the liquid amount display tube 20, and the other part BM2 of the excitation light from the light source 40. However, the excitation light from the light source 40 is branched and guided so that the float 30 is irradiated from the side opposite to one side of the liquid amount display tube 20.

For this reason, the light guide lens 70 branches the excitation light from the light source 40 into BM1 and BM2, and the excitation light branch that irradiates the float 30 from one side of the liquid volume display tube 20 with a part of the excitation light BM1. Part 72;
An excitation light guide 73 that guides another part BM2 of the excitation light from the light source 40 branched by the excitation light branch 72 to the side opposite to one side of the liquid amount display tube 20,
The float 30 is separated from one side of the liquid level display tube 20 by the other part BM2 of the excitation light guided to the side opposite to the one side of the liquid level display tube 20 by the excitation light guide 73. And an excitation light return portion 74 that is turned back so as to irradiate from the opposite side.

  Also, as shown in FIG. 6B, the excitation light branching unit 72 is a liquid for irradiating the float 30 from the lower side in FIG. 6B with a part of the excitation light BM1 from the light source 40. Directly directed to the float 30 in the quantity display tube 20, the other part BM2 of the excitation light from the light source 40 is applied to the excitation light guide 73 in order to irradiate the float 30 from the upper side in FIG. Has a guiding function.

For this reason, the excitation light branching unit 72 emits a part of the excitation light BM1 from the light source 40 so as to be guided directly to the float 30 in the liquid amount display tube 20,
A substantially conical excitation light first reflecting surface 72b for guiding another part BM2 of the excitation light from the light source 40 to the excitation light guide 73 (for reflecting toward the excitation light guide 73);
A substantially frustoconical excitation light second outer reflection surface 72c;
It is comprised by the excitation light 2nd inner reflective surface 72d.

  In addition, the excitation light guide 73 is formed in a partially cylindrical shape surrounding the liquid amount display tube 20. The excitation light guiding unit 73 has a function of guiding the light BM2 guided from the excitation light branching unit 72 to the upper part of the liquid volume display tube 20 and reaching the excitation light folding unit 74. For this reason, the excitation light guide 73 has an excitation light guide outer surface 73a and an excitation light guide inner surface 73b.

  The excitation light folding unit 74 has a function of folding the light BM2 guided from the excitation light guiding unit 73 downward and irradiating the float 30 in the liquid amount display tube 20 from above. For this reason, the excitation light return part 74 has the excitation light return first reflection surface 74a, the excitation light return second reflection surface 74b, and the excitation light second emission surface 74c.

(Third embodiment)
With reference to FIGS. 7-9, the liquid quantity display apparatus of 3rd Embodiment of this invention is demonstrated. The present embodiment is used for a liquid amount display device in which the liquid amount is grasped by directly observing the container liquid surface, for example, a water tank of a humidifier or a dehumidifier.

  A humidifier 100 shown in FIG. 7 includes a humidification processing unit 101, a liquid amount display device 102, and a container 110 that stores water as the liquid W.

  The humidification processing unit 101 atomizes the water supplied from the container 110 inside, and includes a discharge path 101a formed so as to cut the inside of the container 110 and an opening 101b formed at the upper end of the discharge path 101a. Thus, the atomized water is configured to be sprayed out of the humidifier 100.

  The container 110 contains at least a part of the container 110 so that the water supplied to the humidification processing unit 101 can be seen and the float 130 in the liquid amount display device 102 disposed in the container 110 can be visually recognized from the outside. All are configured to be transparent or translucent.

  The liquid amount display device 102 is disposed inside the container 110, and at least a part or all of the liquid amount display tube 120 is transparent or translucent, and a light source 140 disposed below the liquid amount display tube 120. And a float 130 disposed inside the liquid amount display tube 120 and a light receiving unit 150 disposed above the liquid amount display tube 120.

  The liquid level display tube 120 is configured such that the water level of the container 110 and the water level of the liquid level display device 102 are the same level by communicating with the container 110 via a communication pipe (not shown) on the bottom surface. Yes.

  As shown in FIGS. 8 (a) and 8 (b), the liquid amount display tube 120 includes a double tube composed of an outer tube 120a and an inner tube 120b disposed inside the outer tube 120a and spaced from the outer tube 120a. Consists of a tube structure. The outer tube 120a and the inner tube 120b are each formed of a highly transparent resin such as glass or PMMA. The inner tube 120b is formed with an inner diameter larger than the outer diameter of the float 130 so as not to prevent the movement of the float 130.

  A stopper 121 that prevents the float 130 from flowing out and allows water to flow into the container 110 is disposed below the liquid amount display tube 120.

  The float 130 includes at least one light body that emits visible light according to the excitation light of the light source 140. As the light body, for example, a phosphor that absorbs light in the blue light region from the excitation light of the light source 140 and emits light having a longer wavelength than the excitation light is employed.

  As such a phosphor, the phosphor shown in the example of the phosphor when the light source emitting blue light of about 460 nm in the first embodiment is used can be adopted.

Further, as a phosphor that emits visible light and absorbs only blue light _{region, Y 3 Al 5 O 12:} Ce3 + or _{Lu 3 Al 5 O 12: Ce} 3+, Y 3 (Al, Ga) 5 O1 2: Ce _{3+ and the} like.

  The light body is not limited to a phosphor, and a solid such as a fluorescent pigment that emits fluorescence according to incident light, a liquid such as a fluorescent paint that emits fluorescence according to incident light, and a light reflector such as a mirror. It may be adopted. Further, instead of or in addition to the fact that the float 130 includes the light body inside, the float 130 may be provided with a fluorescent paint, or a part or all of the surface of the float 130 is a mirror surface. It may be configured.

  The specific gravity of the float 130 is adjusted so that it floats on the liquid level WL shown in FIGS. The float 130 may be made of a material smaller than the specific gravity of water, or an appropriate cavity may be provided inside the float 130 and the specific gravity may be adjusted so that the float floats in water as a whole. . Further, the float 130 does not necessarily have a spherical shape, and may have a conical shape, a cylindrical shape, a polygonal column, or the like.

  As shown in FIG. 8B, the light source 140 is configured to irradiate the float 130 with water from below through water. As the light emitter of the light source 140, a light emitting diode or a laser diode having a light emission wavelength in a range from ultraviolet light to blue and green light may be employed. It is more preferable that the excitation light intensity of the light emitter is higher. As the light emitter of the light source 140, for example, a light emitting diode that emits near-405 nm near ultraviolet light using a GaN-based material can be employed.

  The light receiving unit 150 includes a light receiver 151 (photodiode) and a case 152 (photodiode case).

  The light receiver 151 is housed in a case 152 installed at the upper end of the liquid level display tube 120 and is downward (inside the liquid level display tube 120) so as to receive light derived from the light body included in the float 130. Is installed.

  The case 152 is made of, for example, a transparent material so as to transmit light derived from the light body. The case 152 may be configured to block light other than the light body included in the float 130 (for example, light derived from the light source 140) by including an optical filter (high-pass filter).

  The processing unit 160 is connected to the light receiving unit 150 and configured to perform processing according to the reception status of the light receiving unit 150.

  The processing unit 160 is configured to perform processing for outputting an output signal corresponding to the light reception state of the light receiving unit 150 to the outside, processing for storing the output signal in a memory, and processing for converting the output signal into a signal indicating a liquid amount. May be. The processing unit 160 also performs processing for stopping heating, processing for notifying that the amount of liquid is low, and supply of liquid when the light receiving state of the light receiving unit 150 indicates that the liquid amount is equal to or less than a predetermined amount. It may be configured to perform a process of stopping the light emission of the light source 140 until there is.

  Further, when the light receiving state of the light receiving unit 150 indicates that the liquid amount is equal to or less than a predetermined liquid amount (for example, the float 130 is blocking the stopper 121), the processing unit 160 keeps the light source 140 constant. You may be comprised so that it may blink at intervals (for example, 2 second lighting, 3 second light extinction, etc.). In this way, the power used for the light source 140 can be saved.

  When the liquid amount display tube 120 is not of a double structure, the difference in refractive index between the liquid amount display tube 120 (for example, resin) and the inside (for example, water) and the outside (for example, water) is small. Diverges as shown in FIG.

  On the other hand, when the liquid amount display tube 120 is formed of a double structure of the outer tube 120a and the inner tube 120b and the space between them is a gas, the inner tube 120b (for example, resin) and the inside (for example, water) and the outside As shown in FIG. 9 (b), the light emitted from the light source 140 efficiently travels through the inner tube 120b due to total reflection as a result of a large difference in refractive index (for example, air). 130 is reached.

  According to the liquid amount display device 102 of the present embodiment, since the light emitted from the light source 140 efficiently reaches the float 130, the light body included in the float 130 emits light more brightly. For this reason, the surface of the liquid or the liquid amount can be sufficiently visually recognized even in a dark place. In addition, since the amount of light received by the light receiving unit 150 is increased, the processing unit 160 can perform processing more appropriately according to the liquid amount.

  Although the illustrated embodiment has been described above, the liquid amount display device of the present invention is not limited to a humidifier, a liquid tank such as a plastic tank, a liquid storage container such as petroleum, a beverage storage container such as a tea server or a water server, It can be used for a beverage production apparatus, a microwave oven with a steam function, or a dehumidifier.

The liquid W is not limited to water and may be any liquid that transmits light. For example, kerosene contained in a liquid tank such as a polytank can be adopted as the liquid W. Also, the phosphor powder is dispersed in glass containing components such as SiO ₂ , B ₂ O ₃ , and Al ₂ O _3. Thus, the light body may be configured. In addition, a phosphor is used by using an oxynitride glass phosphor such as Ca-Si-Al-ON-based or Y-Si-Al-ON-based to which Ce ³⁺ or Eu ²⁺ is added as an activator. It may be configured.

DESCRIPTION OF SYMBOLS 10 Container 20 Liquid quantity display tube 30 Float 40 Light source 50 Light-receiving part 60 Processing part

Claims (6)

A liquid amount display tube that communicates with the inside of the container that contains the liquid and extends in the vertical direction;
A light source that emits light of a predetermined wavelength from the one end side of the liquid amount display tube into the liquid amount display tube;
A light receiving portion arranged on the other end side of the liquid amount display tube and outputting a light receiving signal according to a light receiving state;
A processing unit for processing the received light signal,
A float formed of a material that includes at least one kind of light body that emits visible light according to incident light derived from the light source and floats on the surface of the liquid is accommodated inside the liquid amount display tube. A liquid amount display device characterized by that. It is communicated with the inside of the container that contains the liquid and extends in the vertical direction, and is arranged in the inside of the container, and is formed into an inner and outer double tube structure in which the inner tube and the outer tube are arranged apart from each other. Liquid level indicator tube,
A light source installed on the lower end side of the liquid amount display tube and irradiating light of a predetermined wavelength toward the inner tube;
A light receiving unit that is arranged on the upper end side of the liquid amount display tube and outputs a light reception signal according to a light reception state;
A processing unit for processing the received light signal,
A float formed of a material that includes at least one kind of light body that emits visible light in response to incident light derived from the light source and that floats on the surface of the liquid is housed in the liquid amount display tube. Liquid quantity display device characterized by the above. The liquid amount display device according to claim 1 or 2,
The liquid amount display device, wherein the light receiving unit includes an optical filter that cuts incident light derived from the light source. In the liquid quantity display apparatus of any one of Claims 1-3,
The float as the light body includes a first phosphor having a fluorescence intensity maintenance rate of a predetermined ratio or more when the temperature rises from a predetermined first temperature to a predetermined second temperature, and the first temperature to the second temperature. A liquid amount display device comprising at least one second fluorescent material having a fluorescence intensity maintenance rate of less than the predetermined ratio when the fluorescent light intensity is increased. In the liquid quantity display apparatus of any one of Claims 1-4,
A light guide lens for branching and guiding excitation light from the light source;
In the light guide lens, a part of the excitation light emitted from the light source irradiates the float from one side of the liquid display tube, and the other part of the excitation light emitted from the light source is the float. Branching and guiding excitation light from the light source so as to irradiate from the side opposite to the one side of the liquid amount display tube,
The light guide lens is
An excitation light branching unit that irradiates a part of the excitation light emitted by the light source from the one side of the liquid display tube to the float;
An excitation light guide that guides the remaining part of the excitation light emitted by the light source to the side opposite to the one side of the liquid display tube;
The excitation light guided by the excitation light guide to the side opposite to the one side of the liquid amount display tube is opposite to the one side of the liquid amount display tube with respect to the float. A liquid level display device comprising: an excitation light return portion that is turned back so as to be irradiated from the side. In the liquid quantity display apparatus of any one of Claims 1-5,
The processing unit is configured to stop the irradiation of the light source, the process of adjusting the irradiation interval of the light source, the process of issuing an alarm, and the process of stopping the process for the liquid contained in the container according to the light reception signal. A liquid amount display device that performs at least one of the above.