JP2013122412A - Non-contact liquid detection configuration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact liquid detection configuration which does not require a wide space for installation in an apparatus performing a specific function by using liquid and can detect the liquid even if the liquid is transparent.SOLUTION: The non-contact liquid detection configuration includes: a container body 1 storing liquid therein and composed of a light transmission body having the refractive index of light greater than that of the air; a light-emitting device 4 arranged in one direction to the container body 1 and emitting light; a photodetector 5 outputting an electric signal according to the intensity of reflection light; and direct reflection light shielding means 9 for preventing the light emitted from the light-emitting device 4 and directly reflected on an outer surface 1a of the container body 1 from directly entering a photodetector 5. When liquid 2 is in the container body 1, since the reflection light intensity is decreased and an output signal of the photodetector 5 changes, detection determination can be performed for detecting existence of the liquid. This does not require a wide space for arrangement when the apparatus is installed, and provides the non-contact liquid detection configuration capable of detecting the liquid even when the liquid to be detected is transparent.

Description

  The present invention relates to a non-contact liquid detection configuration for detecting the presence / absence of a liquid in a container mounted on an electric device that uses a transparent liquid such as water stored in the container without contacting the liquid from the outside of the container.

  Conventionally, as a configuration for detecting the presence or absence of a transparent liquid inside a container of this type from the outside of the container without contact with the liquid, an ultrasonic signal is irradiated toward the surface of the liquid, and at this time, the liquid from the surface of the liquid is irradiated. A method of detecting the presence or absence of liquid from the change in the reflection time of the ultrasonic signal is known, but the configuration utilizing this reflection of the ultrasonic signal is very expensive for the ultrasonic element that transmits and receives the ultrasonic signal. For this reason, it is used only in expensive measuring instruments and devices that require high accuracy for liquid detection, and has not been used in general electric devices.

  As a configuration that is relatively inexpensive and can be used in a wide range of general electrical equipment, there is a configuration that applies the refraction action of light by a liquid. For example, a configuration in which a light emitting element and a light receiving element are formed of a light transmitting body outside a container. The light is output from the light emitting element, and the output light is transmitted through the container and refracted at the boundary surface between the container and the liquid. A device that detects the presence or absence of liquid is known (for example, see Patent Document 1).

  Hereinafter, the power supply configuration of the electric device will be described with reference to FIG.

  With respect to the boundary surface 102 between the container side wall of the liquid 101 to be detected inside the container body 100 and the liquid in contact with the corner portion of the container body 100 that stores liquid made of polyethylene or the like that transmits infrared rays. The infrared light emitting element 103 is disposed so that infrared rays are incident at an angle other than perpendicular, and the infrared light receiving element 104 is disposed at a position facing the infrared light emitting element 103 on an extension line in the infrared incident direction. The infrared light emitting element 103 and the infrared light receiving element 104 are arranged to sandwich the corner of the container body 100 from the outside, and signal processing of an electrical output signal proportional to the amount of light received output from the infrared light receiving element 104 is performed. When the control circuit unit 105 is provided and the liquid to be detected 101 does not exist inside the container body 100, the infrared light output from the infrared light emitting element 103 passes through the container body 100 and directly receives the infrared light. A large electrical output signal is output from the infrared light receiving element 104 to be input to the child element 104, and when the liquid to be detected 101 is inside the container body 100, the infrared light output from the infrared light emitting element 103 is Since the infrared light receiving element 103 is refracted at the boundary surface 102 between the container body 100 and the liquid to be detected 101 and bent in a direction where the infrared light receiving element 104 is not installed, the liquid to be detected enters the container body 100 from the infrared light emitting element 103. Since a reduced electrical output signal is output with respect to the case where there is no 101, the detected liquid 101 inside the container body 100 in the control circuit unit 105 from the change in the electrical output signal output from the infrared light receiving element 104. Whether or not there is is determined.

  However, in the non-contact liquid detection configuration described above, it is necessary to arrange the infrared light emitting element 103 and the infrared light receiving element 104 serving as the detection configuration to face each other with a distance between them so as to sandwich the corner portion of the container body 100. Since it is a certain configuration, the arrangement position with respect to the container body 100 is limited, and a space for disposing the detection portion at a distance from each other is necessary, so that there is a restriction on the arrangement position when mounting on the device. .

  For such a configuration in which the arrangement position at the time of mounting is limited, it is possible to detect liquid without requiring a wide space by arranging the detection unit in one direction outside the container, and There is also known a detection method based on reflection of light that can be configured relatively inexpensively.

  As an example, as a method for an ink jet printer that detects the presence or absence of colored ink from the outside of the ink tank, the ink tank is formed of a light transmitting body, and a porous ink occlusion body is packed inside the ink tank to fill the ink. In the impregnated configuration, a light emitting unit that projects light onto the ink tank and a light receiving unit that receives reflected light from the ink tank and generates an output signal corresponding to the intensity of the reflected light are disposed outside the ink tank. As a result, when the ink occlusion body is impregnated with ink, the ink occlusion body reflects against the unimpregnated state, and the reflected light from the ink tank to the light receiving portion decreases, and is generated from the light receiving portion. Therefore, the presence or absence of ink is detected because the output signal is reduced (see, for example, Patent Document 2).

  Hereinafter, the power supply configuration of the electric device will be described with reference to FIG.

  An ink tank 200 for storing colored ink is configured by filling an ink storage body 202 made of a porous polyurethane foam material inside a container body 201 made of a material having a light refractive index of 50% or more. The ink is stored in the ink tank 200 by impregnating the ink storage body 202.

  A reflective photosensor 203 is disposed on the outer side surface of the container body 201 as a detection means for detecting ink in a non-contact manner with the container body 201.

  The reflection type photosensor 203 includes a light emitting diode 204 that is a light emitting unit for projecting light onto the container body 201 and a light receiving transistor 205 that is a light receiving unit for reflected light from the container body 201. .

  With such a configuration, part of the light projected from the light emitting diode 204 is directly reflected by the surface of the side wall 201c of the container body 201, and part of the light is absorbed by the side wall 201c, and the remaining light transmitted through the side wall 201c remains. The ink occluding body 202 is irradiated, and part of the light irradiating the ink occluding body 202 is absorbed by the ink occluding body 202, the rest is reflected by the ink occluding body 202, and further the ink occluding body. A part of the light reflected by 202 is further reflected by the surface of the side wall 201c of the container body 201, a part is absorbed by the side wall 201c, and the remainder transmitted through the side wall 201c irradiates the light receiving transistor 205. .

  At this time, the light receiving transistor 205 receives the reflected light from the container body 201 irradiated and received, and generates an output voltage as an output signal corresponding to the intensity of the received light. The reflectivity when 202 receives light is such that the greater the amount of ink impregnated, the more light is absorbed by the pigment of the ink and the reflectivity decreases, so the output voltage of the light receiving transistor 205 is also the amount of impregnated ink. It will be lower than when there is little.

  Therefore, since the output voltage of the light receiving transistor 205 increases due to the consumption of ink, the presence or absence of ink in the ink tank 200 can be determined from the change in the output voltage.

JP 2000-329609 A JP-A-9-314854

  In such a conventional non-contact liquid detection configuration, the intensity of the reflected light is based on the fact that the liquid to be detected is a colored liquid that is ink, and the reflectance of light decreases due to light absorption by the pigment. Since there is a method for detecting the presence or absence of liquid from the change of the liquid, when the liquid to be detected is a transparent body, there is a problem that it is difficult to detect the presence or absence of liquid because there is no difference in light absorption. .

  Therefore, the present invention solves the above-described conventional problems, does not require a wide space for placement when mounted on a device, and enables non-contact detection even when the liquid to be detected is a transparent body An object is to provide a liquid sensing arrangement.

  And in order to achieve this object, the present invention is installed in a configuration that has a specific function by storing a transparent liquid in a container provided in an apparatus and utilizing the liquid stored in the container. A container body that is provided with a space for storing liquid therein, and is configured with a light transmitting body having a refractive index of light larger than that of air, and a container that is arranged outside the container body in one direction with respect to the container body A light emitting element that irradiates light on the body, a light receiving element that outputs an electric signal in accordance with the intensity of reflected light from the container body, and the light emitted from the light emitting element is directly reflected on the outer surface of the container body Provided with direct reflection light shielding means that shields the direct incidence of reflected light that does not change in the presence or absence of liquid to the light receiving element, light at the interface between the container body and the liquid when there is no liquid inside the container body Increases the amount of transmitted light to the light receiving element Since the intensity of the reflected light is reduced, the presence or absence of liquid is detected by judging the decrease in the intensity of the reflected light from the change in the output signal of the light receiving element. To achieve this goal.

  Further, the present invention provides a device configuration in which a portion of the container body is exposed to the outside of the device with the container body mounted on the device, or the container body can be attached to and detached from the device. A direct external light incident preventing means for preventing direct incidence is provided.

  According to the present invention, a transparent liquid is stored in a container provided in an apparatus, and the liquid stored in the container is used for a configuration having a specific function by utilizing the liquid stored in the container. And a light emitting element for irradiating light to a container body arranged in one direction with respect to the container body outside the container body And a light receiving element that outputs an electrical signal that matches the intensity of the reflected light from the container body, and reflected light that does not change depending on the presence or absence of liquid that is directly reflected on the outer surface of the container body by light emitted from the light emitting element Direct reflection light shielding means for blocking direct incidence on the light receiving element of the light receiving element, and the amount of light transmitted at the interface between the container body and the liquid increases with respect to the state where there is no liquid inside the container body. The intensity of reflected light incident on the element decreases. Therefore, by determining the decrease in the intensity of the reflected light from the change in the output signal of the light receiving element, the presence or absence of liquid is detected and determined. Since it is arranged side by side in the direction, it does not require a large space for installation when mounted on the device, and is directly reflected by the surface of the container body that does not change depending on the presence or absence of liquid by the direct reflected light shielding means, and directly enters the light receiving element. The light receiving element can receive only the reflected light from the inside of the outer surface of the container that changes depending on the presence or absence of liquid by blocking the light that is generated, and the container body has a refractive index greater than that of the air to increase the liquid inside. If there is, the presence or absence of the liquid can be determined based on the increase in the amount of light transmitted at the interface between the container body and the liquid, so that the detection can be performed even if the liquid to be detected is a transparent body. about It can be.

  Further, according to the present invention, in a configuration of a device in which a portion of the container body is exposed to the outside of the device with the container body mounted on the device, or the container body can be attached to and detached from the device, an external device from the outside of the device with respect to the light receiving element By having a configuration including direct external light incident prevention means for preventing direct incidence of light, external light incident on the light receiving element from the outside of the apparatus is blocked by the external light incident prevention means. Because the light receiving element is not easily affected by extraneous light other than the light emitted from the light emitting element, which is a major factor in liquid detection, even when the container part is exposed from the device or when the container is removed from the device. The effect that the detection of the presence or absence of liquid is more stable can be obtained.

Sectional drawing which expanded and showed the principal part of the non-contact liquid detection structure of Embodiment 1 of this invention Sectional view showing the principle by enlarging the main part of the liquid detection configuration The figure which expanded the principal part of the same liquid detection structure, and showed the supplement of the principle ((a) state diagram of 1st light transmission, (b) state diagram of 2nd light transmission) Chart showing changes in reflected light intensity in the same liquid detection configuration Circuit diagram showing outline of circuit configuration of liquid detection configuration The front view which fractured | ruptured and showed the principal part of the non-contact liquid detection structure of Embodiment 2 of this invention Plan view showing the main part of the same liquid detection configuration broken away Front view showing the main part of the liquid detection configuration enlarged and broken. Left side view showing the main part in another configuration of the liquid detection configuration enlarged and broken. The top view which expanded and fractured and showed the principal part of the same liquid detection composition Left side view showing the main part of the liquid detection configuration enlarged and broken. Front view showing the main part in the configuration in which a light blocking body is added to the liquid detection configuration in an enlarged manner and broken. The top view which showed the composition of the shading body added to the same liquid detection composition Cross-sectional configuration diagram showing an enlarged main part of a conventional liquid detection configuration Cross-sectional configuration diagram showing an enlarged main part of another conventional liquid detection configuration

  The non-contact liquid detection configuration according to claim 1 of the present invention is configured to store a transparent liquid in a container provided in an apparatus and to perform a specific function by utilizing the liquid stored in the container. A space for storing liquid inside is provided, and a container body constituted by a light transmitting body having a refractive index of light larger than that of air, and arranged outside the container body in one direction with respect to the container body. A light emitting element that irradiates light to the container body, a light receiving element that outputs an electrical signal that matches the intensity of the reflected light from the container body, and the light emitted from the light emitting element is directly reflected on the outer surface of the container body. Direct reflection light shielding means for blocking direct incidence of reflected light that does not change depending on the presence or absence of liquid to the light receiving element, at the interface between the container body and the liquid when there is no liquid inside the container body Increasing the amount of light transmitted to the light receiving element The intensity of the reflected light morphism from be lowered, with a detection determining arrangement the existence of liquid by determining the decrease in the intensity of the reflected light from the change in the output signal of the light receiving element. As a result, the light emitting element and the light receiving element are arranged side by side in one direction with respect to the outside of the container body, so that a large space is not required for placement when the device is mounted, and the liquid is directly shielded by the reflected light shielding means. The light receiving element can receive only the reflected light from the inside of the outer surface of the container that changes depending on the presence or absence of liquid, by blocking the light that is reflected by the surface of the container that does not change depending on the presence or absence and directly enters the light receiving element. The presence of liquid can be determined based on the fact that the amount of light transmitted at the interface between the container body and the liquid increases if there is liquid inside by making the refractive index of the container body larger than that of air. Even if the liquid is a transparent body, there is an effect that detection is possible.

  In addition, in the configuration of the device in which the container body part is exposed to the outside of the device with the container body mounted on the device, or the container body can be detached from the device, direct external light from the outside of the device to the light receiving element. Since the structure is provided with the direct external light incident preventing means for preventing the incident, the external light incident on the light receiving element from the outside of the device is blocked by the direct external light incident preventing means. Even in a configuration with exposed or in a state where the container is removed from the device, the light receiving element is not easily affected by extraneous light other than the light emitted from the light emitting element, which is the main cause of liquid detection. The effect is that the detection is stabilized.

  In addition, in the configuration of the device in which the container body part is exposed to the outside of the device with the container body mounted on the device, external light including indirect light from the outside of the device to the light receiving element is blocked inside the container body. Even if the container part is exposed from the device by reducing the direct incidence of extraneous light including indirect light to the light receiving element, the light receiving element can detect the liquid. Since it becomes more difficult to be affected by extraneous light other than the light emitted from the light emitting element, which is the main factor, the detection of the presence or absence of liquid is more stable.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
1 and 2 are cross-sectional views showing an enlarged part of a side surface of a container for storing a liquid mounted on the device. This container has a space inside a container body 1 forming an outer shell. In this configuration, the liquid 2 for use in equipment is stored in the space.

  The liquid 2 is reduced by being used in equipment, and by being pulled by gravity in the downward direction in the drawing, the space 3 filled with air is gradually expanded upward. Become.

  Here, the liquid 2 is a transparent body as an object, for example, water.

  An example of a device that uses water as the liquid 2 is a humidifier. When the device is the humidifier, the container body 1 generates a tank for storing water for humidification or humidified air. In general, it is configured so that the user can supply water to the tank and clean the tray by making it removable from the main body of the equipment when hitting the tray for evaporating water.

  Here, the container body 1 is made of a material that is light transmissive and has a refractive index larger than that of air.

  Thus, if the liquid 2 is water and the liquid has a refractive index of about 1.33, for example, polyethylene (refractive index: about 1.5), polyethylene terephthalate (refractive index: about 1.6), or polystyrene It is a resin material that is not violated by water such as (refractive index: about 1.6), and is formed by blow molding or mold molding at a thickness of about 0.5 mm to about 2 mm.

  Note that the refractive index of the space 3 when the liquid 2 is not present inside the container body 1 is approximately 1 in a device that is filled with general air.

  The side surface of the container body 1 receives the light emitting element 4 that irradiates the container body 1 with light at a position where it is desired to determine the decrease in the liquid 2, and the reflected light from the container body 1. The light receiving element 5 that outputs an electrical signal corresponding to the strength is placed close to each other and arranged in one direction in parallel with the outer surface 1a of the container body 1.

  Here, since the light emitted from the light emitting element 4 is not intended to display or notify the state of the device, light that does not bother the user (light outside visible light) is desirable and relatively For example, an infrared LED that emits infrared light having a wavelength of about 900 nm by passing a direct current is desirable.

  Here, the light receiving element 5 receives infrared light emitted from the light emitting element 4 and outputs an electrical signal corresponding to the received light. It is desirable that the element is relatively inexpensive and highly available. Thus, for example, a phototransistor is used which is encapsulated with a resin having an optical filter performance for attenuating visible light other than infrared light irradiated by the light emitting element 4 and changes the conduction current in accordance with the amount of received light. .

  The light-emitting element 4 and the light-receiving element 5 have a cylindrical shape that is substantially perpendicular to the outer surface 1a of the container body 1 in the detection structure outer shell 6 in order to protect each element while keeping the position of the arrangement relative to the container body 1 constant. The optical path cylinders 7a and 7b are provided, and are configured to be mounted and fixed to the respective cylinders.

  In the figure, the light-emitting element 4 and the light-receiving element 5 are shown in the vertical direction for the sake of convenience in order to explain the positional relationship between the light-emitting element 4 and the light-receiving element 5 while indicating the position of the liquid 2 in the container body 1. However, in actual use, the detection position of the presence or absence of the liquid 2 is stabilized as the surface position of the liquid 2 by arranging it so as to be parallel to the surface of the liquid 2. Here, the detection configuration outline 6 is a configuration in which the container 1 of the humidifier shown as an example of the mounted device is fixedly disposed on the device side in consideration of the configuration in which the container body 1 is removed from the device main body and used. Therefore, the detection configuration outer shell 6 is formed by molding with an insulator and having excellent molding quality, for example, acrylonitrile, butadiene, styrene resin, etc. as a part of the outer shell of the device.

  In addition, a protective sheet 8 made of a light transmitting body is attached to the surface of the detection structure outer shell 6 facing the container body 1 with the optical path cylinders 7a and 7b covered with an adhesive, thereby allowing dust and liquid to enter. It is preventing.

  Here, the protective sheet 8 is transparent and excellent in transparency with respect to the wavelength of light irradiated by the light receiving element 5, and is preferably a tough material even in the form of a thin sheet, for example, a methacrylic resin having a thickness of 0.3 mm to 0.7 mm. The sheet material is cut by a mold and is bonded and fixed to the detection structure outer shell 6 using an acrylic adhesive.

  The light-emitting element 4 and the light-receiving element 5 are mounted on the optical path cylinders 7a and 7b provided in the detection configuration outer shell 6 to fix the position of the arrangement relative to the container body 1, but are also arranged relative to the optical path cylinders 7a and 7b. By directing the light, the light incident from the light emitting element 4 or the light directly reflected by the outer surface 1a of the container body 1 is blocked from being directly incident on the light receiving element 5, and is surrounded by a wavy line in the figure. By constructing the direct reflection light shielding means 9, only the reflected light from the inside can be received by the light receiving element 5 even at the position of the outer surface 1 a of the container body 1.

  First, the configuration and operation of the direct reflected light shielding means 9 will be described with reference to FIG.

  FIG. 2 shows the positional relationship by cutting the container body 1 and the detection structural outline 6 on the plane where the light receiving elements 5 of the light emitting elements 4 are arranged, and the light emitted from the light emitting elements 4 and incident on the light receiving elements 5 as reflected light. It is the block diagram which showed the optical path of light typically by the arrow line.

  The light emitted when the light emitting element 4 is an LED is generally irradiated in a conical shape from one point, which is the light emitting portion of the light emitting element 4, in the light emission direction. Is arranged inside the optical path cylinder 7a so that it is shielded by the inner surface of the optical path cylinder 7a, so that only the opening 10a of the optical path cylinder 7a is centered on the light emitting axis, and the conical shape as indicated by the wavy line in the figure. The container body 1 is irradiated.

  A part of the light irradiated to the container body 1 in a conical shape is first specularly reflected based on a so-called reflection law in which the outer surface 1a of the container body 1 has a reflection angle equal to the incident angle with respect to the outer surface 1a. The light is reflected based on the above action and returns in the direction of the light receiving element 5.

  By the way, the intensity of light reflected on the surface of the outer surface 1a depends only on the smoothness of the surface of the outer surface 1a, and basically does not depend on the presence or absence of the liquid 2 inside the container body 1. Further, although it depends on the incident angle of light on the outer surface 1a, it is a direct reflection with few attenuation elements on the surface of the outer surface 1a, and therefore returns from the container 1 to the light receiving element 5 by reflection. It accounts for many parts of the reflected light.

  Therefore, in the configuration in which the presence / absence of the liquid 2 inside the container body 1 is determined based on the change in the reflected light intensity, the directly reflected light on the surface of the outer surface 1a is unnecessary, and the container body 1 It becomes a factor which disturbs detection by the light receiving element 5 of the reflected light from the inside rather than the outer surface 1a.

  Therefore, the direct reflected light shielding means 9 is provided in order to eliminate this interference factor, and the light emitting element 4 and the light receiving element 5 are arranged in the detection structure outer shell 6 with respect to the container body 1 as shown in the figure. As shown by an arrow line 11a in the drawing, the optical path cylinder 7a is arranged so that the light irradiated from the light emitting element 4 and directly reflected by the outer surface 1a of the container body 1 does not enter the light receiving element 5 in the positional relationship of It arrange | positions in the positional relationship which blocks | interrupts with the edge of the opening part 10a.

  From this, the details of the positional relationship of each component in the direct reflected light shielding means 9 will depend on the overall configuration of the non-contact liquid detection. For example, a light emitting element that is a bullet type LED having an outer diameter of φ5 mm 4 and a configuration in which the light receiving elements 5 having the same shape are arranged at an interval of 5 mm as an example, a configuration in which the interval between the container body 1 and the detection configuration outer shell 6 is set to about 4 mm or less becomes a disturbing factor. Incidence of the directly reflected light to the light receiving element 5 can be prevented.

  Next, details of a method for determining the presence / absence of the liquid 2 inside the container body 1 based on a change in reflected light intensity will be described with reference to FIGS. 3 and 4.

  FIG. 3 is an enlarged cross-sectional view showing a part of the container body 1 that receives the light irradiated by the light emitting element 4, and shows the difference between the reflected light and the transmitted light depending on the presence or absence of the liquid 2 with the width of the arrow line. The intensity is schematically shown excluding the element of the refraction angle.

  In the figure, the light-emitting element 4 is irradiated with light from the right side of the container body 1 and is incident on the container body 1 in the light conically spreading from the light-emitting element 4 at approximately 45 ° C. It represents the state of reflection and transmission in one optical path.

  The light emitted from the light emitting element 4 first reaches the outer surface 1 a of the container body 1. At this time, a part of the light reaching based on the law of reflection on the outer surface 1 a is directed outward of the container body 1. It is reflected directly (arrow line 11a in the figure), and the remainder passes through the inside of the container body 1.

  As described above, the directly reflected light in the outward direction of the container body 1 at this time is the same regardless of the presence or absence of the liquid 2, and thus the light transmitted to the inside of the container body 1 is also the same.

  Next, the light transmitted to the inside of the container body 1 reaches the inner surface 1b of the container body 1 inside the container body 1, but when there is no liquid 2 inside the container body 1 Based on the difference in refractive index between air, which is a gas that occupies the space 1 inside the container body 1 and the liquid 2, and the container body 1, the state changes to the state of reflection and transmission on the inner surface 1b. Will occur.

  Here, light passing through the interface of an object having a different refractive index varies depending on the incident angle, but based on the law of refraction, when traveling in the direction of an object having a higher refractive index, the refractive index in the propulsion direction of the light By bending the optical path toward the larger object side, it becomes easier to transmit as a whole, and when traveling in the direction of an object with a lower refractive index, the optical path is bent at a shallower angle than the incident angle. As a result, a more difficult state of transmission occurs.

  Therefore, as described above, when the liquid 2 with a refractive index of 1.33, which is water, is inside the container body 1 with a refractive index of about 1.5, the refractive index when there is no liquid 2 inside is as follows. As a whole, the light transmission in the direction of the liquid 2 is increased with respect to the time when the light travels through the one space portion 3.

  As a result, the light transmitted to the space 3 side of the container body 1 on the inner surface 1b becomes larger if the liquid 2 is present inside the container body 1 (arrow line 11b2> arrow line 11b1 in the figure) On the contrary, the intensity of the light reflected in the light entering direction inside the container body 1 is reduced (arrow line 11c1> arrow line 11c2 in the figure).

  The light reflected in the light entering direction inside the container body 1 is transmitted and reflected again at the interface of the outer surface 1a of the container body 1, and the outer surface 1a of the container body 1 is By transmitting light to the outside of the outer surface 1a and the inner surface 1b while repeating reflection between the inner surface 1b, the position where the light is incident on the container body 1 is initially spread around the center and gradually attenuated. Will go.

  Therefore, even when this light attenuation state is observed as reflected light that is transmitted from the light receiving element 5 side to the outer surface 1a side of the container body 1 and returns to the light receiving element 5 side, the radiation of the light emitting element 4 is observed. With the center of light as the central axis, the light intensity gradually decreases as the distance from the central axis increases.

  FIG. 4 shows the attenuation state of the light intensity as a curve. When the vertical axis is the reflected light intensity Lv and the center of the emitted light of the light emitting element 4 is the central axis, the horizontal axis is from the central axis. The distance Di is a distance Di, and the change in reflected light intensity Lv at a position away from the central axis is expressed by a solid line when the liquid 2 is present, and a dotted line when it is not present, and the difference is simplified. It is.

  Accordingly, in the figure, the position of the arrow P1 is the arrangement position of the light emitting element 4, and the intensity of the reflected light is maximized, but the liquid 2 is not present inside the container body 1 as compared with the liquid as described above. When 2 is present, the light transmittance to the inner surface 1b side of the container body 1 is increased, so that the intensity of the reflected light is lowered.

  Here, in the figure, when the light receiving element 5 is arranged at the position of the arrow P2 away from the central axis, the liquid 2 is not present inside the container body 1 even at this position. Accordingly, the intensity of the reflected light is lowered, and the difference in intensity of the reflected light as shown by ΔLv in the figure with respect to the presence or absence of the liquid 2 occurs.

  The intensity or difference of the reflected light is basically irradiated from the light emitting element 4 if there is no change in the constituent material of the container body 1 or the properties of the liquid 2 and the position of the light emitting element 4 relative to the container body 1. It becomes relatively constant according to the intensity of light to be transmitted.

  Therefore, the intensity of the reflected light incident on the light receiving element 5 changes depending on the presence or absence of the liquid 2, and the light receiving element 5 is an element that outputs an electrical signal corresponding to the intensity of the received light. If the difference due to the presence or absence of the liquid 2 in the electrical signal output from is grasped in advance, the presence or absence of the liquid 2 can be determined.

  In addition, when the container body 1 is composed of a transparent body having a very high light transmittance and a light transmittance close to 100%, most of the incident light is basically transmitted to the inside of the container body 1. Thus, since the change in reflected light intensity from the container body 1 side due to the presence or absence of the liquid 2 becomes small, it is difficult to determine the presence or absence of the liquid 2 from the change in the electrical signal output from the light receiving element 5. Become.

  Therefore, the constituent material of the container body 1 is approximately 40 to 95% light with respect to the transparent body close to 100% due to the natural color or pigment coloring of the resin at the wavelength of light emitted from the light emitting element 4. The transmittance is desirable.

  Next, a circuit configuration for outputting an electric signal by light emission of the light emitting element 4 and reflected light reception of the light receiving element 5 will be described with reference to FIG.

  As shown in the figure, the infrared LED as the light emitting element 4 has a DC power source 12a for intermittently applying a DC power source on the anode side and a current limiting resistor 13a on the cathode side connected in series. Yes.

  Further, the phototransistor which is the light receiving element 5 is connected to the collector side with a positive potential of a DC power source 12b serving as a power supply source, and on the emitter side is a resistor for taking out the current conducted by the phototransistor as a voltage signal. 13b are connected in series.

  Here, the DC power supply 12a is not particularly limited as long as the DC power supply 12a can output a stabilized DC voltage or can output intermittently, but for example, a step-down voltage obtaining a stabilized DC low-voltage power supply from a commercial power supply. Type stabilized switching power supply, a configuration capable of outputting a stabilized voltage by a general stabilized power supply that makes the power of a primary battery or a secondary battery constant by a voltage stabilizing regulator, and the stabilized power supply Output power is intermittently output at regular intervals by a switching element such as a transistor.

  The details of the power supply applied to the light emitting element 4 by the DC power supply 12a are not particularly specified. For example, the voltage is applied to the light emitting element 4 for 5 msec with a voltage of 5 V as a period of 50 msec. In addition, the resistance value of the resistor 13a is selected so that a current of about 20 mA to 50 mA flows through the light emitting element 4 when a voltage is applied.

  Here, the configuration of the DC power supply 12b is not limited as long as it can output a stabilized DC voltage. For example, a step-down stabilized switching power supply device that obtains a stabilized DC low-voltage power supply from a commercial power supply, 1 The power supply of the secondary or secondary battery is constituted by a general stabilized power supply device that makes the voltage constant by a voltage stabilizing regulator.

  The voltage applied to the light receiving element 5 by the DC power source 12b is, for example, 5 V. At this time, when light is irradiated from the light emitting element 4 and reflected and incident on the light receiving element 5, it is applied to both ends of the resistor 13b. The resistance value of the resistor 13b is set so that an output voltage of about 2.5V is generated. For example, the resistance value is set as a value from 10 kΩ to 200 kΩ.

  With the circuit configuration as described above, when the light, which is infrared light reflected from the surface direction of the liquid 2 inside the container body 1 and irradiated from the light emitting element 4, enters the light receiving element 5, the resistor 13 b receives the light receiving element 5. Since a voltage at both ends corresponding to the incident intensity is generated, the state of change in the voltage value generated at both ends of the resistor 13b can be handled as an electrical signal corresponding to the received intensity output from the light receiving element 5. It becomes.

  The means for directly determining whether the liquid 2 is present inside the container body 1 by confirming the change in the electrical signal output from the light receiving element 5 is not the gist of the present invention. Although detailed description thereof will be omitted, in an electric device having an electric control function, a central processing unit (CPU), an input / output device, an analog / digital conversion as a control means for controlling the device. In general, a so-called one-chip microcomputer or the like that incorporates an input device (A / D), a read-only memory (ROM), and a read / write memory (RAM) is mounted.

  Therefore, by utilizing the function of this one-chip microcomputer, the electric signal output from the light receiving element 5 is taken into the inside of the one-chip microcomputer as a voltage value by an analog / digital conversion input device (A / D). An algorithm is defined so that the presence / absence of the liquid 2 is determined based on the difference in the electrical signal inside the one-chip microcomputer, and the defined program is stored on a read-only memory (ROM). Thus, the determination means for the liquid 2 can be configured without adding a new element to the device.

  According to such a configuration, the light-emitting element 4 that irradiates light to the outer surface 1a of the container body 1 and the reflected light from the container body 1 are received, and the received light. Since it is possible to detect the liquid 2 by arranging the light receiving elements 5 that output an electric signal corresponding to the intensity of the light receiving elements 5 so as to be close to the container body 1, a large space is not required for the arrangement when the device is mounted. A contact liquid sensing arrangement can be provided.

  Further, the direct reflected light shielding means 9 changes depending on the presence or absence of the liquid 2 inside the container body 1 among the light that is irradiated from the light emitting element 4 and returns to the light receiving element 5 side as reflected light from the container body 1 side. Without detecting the presence or absence of the liquid 2, the light directly reflected by the outer surface 1a of the container body 1 occupying most of the reflected light from the container body 1 is blocked from entering the light receiving element 5. If there is a liquid 2 having a refractive index larger than that of air inside the container body 1 having a refractive index close to that of the liquid 2 while eliminating the obstruction factor, the light container element 1 irradiated by the light-emitting element 4 according to the law of refraction. The transmittance to the inner surface 1b side is increased, and the reflected light intensity to the light receiving element 5 side is decreased, and the change in reflected light intensity that changes depending on the presence or absence of the liquid 2 is output from the light receiving element 5. Since the presence or absence of the liquid 2 can be detected by determining the change in Body to allow detection even transparent body, it is possible to provide a liquid detection configuration of the non-contact.

(Embodiment 2)
6 to 11, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, a configuration in which a portion of the container body 1 is exposed to the outside of the device with the container body 1 mounted on the device, or the container body 1 can be attached to and detached from the device with respect to the configuration of the first embodiment. In the configuration, a direct external light incident preventing means 14 for preventing direct incidence of external light from the outside of the device is also provided for the light receiving element.

  With respect to this direct external light incident preventing means 14, referring to FIGS. 6 to 8, an example of the configuration of the device in which the container body 1 is exposed to the outside of the device with the container body 1 mounted is utilized using water. A description will be given based on a general humidifier used in a home or the like that provides a humidification function.

  Here, the configuration of the general humidifier is not a main element of the present invention, and therefore detailed description thereof will be omitted, but the outline is as follows.

  As shown in the figure, the humidifying device is for humidification which is detachable from the lateral direction with respect to the device shell 15 so that the user can perform maintenance on the lower side of the device shell 15 constituting the main structure of the main body. A dish-shaped humidified water tray 16 is provided.

  Further, water for humidification is stored in a humidified water tank 17 having a hollow inside, and the humidified water tank 17 is connected to one end of the humidified water tray 16 in a state where the humidified water tray 16 is attached to the outer shell 15 of the apparatus. By adopting a detachable configuration, when the water stored in the humidified water tank 17 becomes empty due to the humidification, the user can replenish the water by removing only the humidified water tank 17 from the device shell 15. It is said.

  A blower 18 is incorporated inside the device shell 15 to take in the outside air and generate a flow of air that is blown out again.

  Porous humidification filter 19 for humidifying air by absorbing water based on capillary action as an arrangement in which a portion of the humidified water tray 16 is immersed in the accumulated water and evaporating the absorbed water on the surface. Is arranged.

  Although not instructed in the drawing, the humidifying water tank 17 is provided with a water inlet for containing water, and a tank lid 20 that is detachable by a screw structure is attached to the water inlet so that the water inside is externally provided. To prevent leakage.

  The tank lid 20 is provided with a water guide valve which is not instructed in the figure but is always closed against the resistance of the spring. When the humidifying water tank 17 is attached to the humidifying water tray 16, the tank lid 20 is attached. In the downward direction, when the tank lid 20 is in contact with the fixed position of the humidifying water tray 16, the humidifying water tank is maintained by the action of gravity so as to keep the water depth in the humidifying water tray 16 regulated by opening the water guide valve. 17 is configured to supply water stored in 17.

  Here, the humidified water tray 16 and the humidified water tank 17 correspond to the container body 1 described above, and is made of a resin material that is unlikely to deteriorate or corrode against water during long-term use. Furthermore, the humidified water tank 17 is generally composed of a light transmitting body whose inside can be visually checked so that the presence or absence of water can be determined by the user of the apparatus.

  In addition, the constituent materials of the device outer shell 15 and the humidifying water tray 16 are generally light-transmitting materials that allow the interior to be seen through by the transmitted light of light in consideration of a variety of colors and a design that matches the interior. Is not used.

  With such a configuration of the humidifier, in the state where the humidifier water tray 16 and the humidifier water tank 17 are attached to the outer shell 15, the blower 18 is applied to the humidifier filter 19 that is partially immersed in the water stored in the humidifier water tray 16. When the wind flow is applied, the humidified air generated by the evaporation of water on the surface of the humidifying filter 19 is sequentially blown out of the outer shell 15 to humidify the surroundings, thereby fulfilling the function of the humidifying device.

  Here, as the humidification progresses, the water in the humidified water tray 16 is consumed and the water level is lowered, and water is sequentially supplied from the humidified water tank 17, but the water stored in the humidified water tank 17 is reduced. When all of the water is supplied and the water accumulated in the humidifying water tray 16 is also consumed, the main function as the humidifying device is lost.

  Therefore, in this humidifying device, the function of prompting the supply of water by notifying the user of the drought state is indispensable as a device, and therefore a configuration for detecting and judging the drought state is necessary. It turns out that it is important.

  In such a configuration of the humidifying device, in order to determine the drought state based on the reflection of light, as shown in the figure, the removal and attachment of the humidifying water tank 17 to the device outer shell 15 is hindered. In the state where the humidified water tank 17 is attached to the apparatus outer shell 15, the water that becomes the liquid 2 from the lateral direction at the upper part of the tank lid 20 that is the lowest part of the humidified water tank 17 that is the container body 1. A method of detecting the presence or absence of the above can be considered.

  In the configuration for detecting the presence or absence of the liquid 2 of this system, an arrangement is adopted in which the light receiving element 5 receives the reflected light by illuminating the upper side of the tank lid 20 attached to the humidifying water tank 17 with the irradiation light of the light emitting element 4 from the lateral direction. As a premise, the direct extraneous light incident preventing means 14 fixes the detection constitution outer shell 6 inside the device outer shell 15 so that the light irradiation direction of the light emitting element 4 and the light receiving direction of the light receiving device 5 face the inner side of the device outer shell 15. It is constituted by.

  Similarly, in the configuration of the direct extraneous light incident preventing means 14, the light receiving direction of the light receiving element 5 is arranged from the lateral direction of the humidified water tank 17 toward the inside of the apparatus outer shell 15, so that the light receiving direction of the light receiving element 5 is set. Is shielded from the outside of the apparatus by the configuration of the device outer shell 15, and even when the humidifying water tank 17 is detached from the device outer shell 15, the removal direction of the humidifying water tank 17 and the light receiving direction of the light receiving element 5 are perpendicular to the device outer shell 15. Therefore, direct incidence of extraneous light on the light receiving element 5 can be prevented.

  Further, in the configuration of the humidifying device, in order to determine the drought state based on the reflection of light, as shown in FIGS. 9 to 11, the humidifying water tray 16 is removed from or attached to the device outer shell 15. In a state in which the humidifying water tray 16 is attached to the apparatus outer shell 15 so as not to cause any trouble, the water that becomes the liquid 2 accumulated inside from a lateral direction in a part of the humidifying water tray 16 that is the container body 1 is provided. A method for detecting the presence or absence of the above is also conceivable.

  In the configuration for detecting the presence or absence of the liquid 2 of this type, the direct external light incident preventing means 14 is arranged at the position where the liquid 2 is accumulated inside the humidifying water tray 16 so that the side surface of the humidifying water tray 16 is light-emitting element from the lateral direction. 4 in which the reflected light is received by the light receiving element 5 by illuminating with the irradiation light 4, the light emitting direction of the light emitting element 4 and the light receiving direction of the light receiving element 5 are perpendicular to the direction in which the humidifying water tray 16 is removed from the outer shell 15. The detection configuration outer shell 6 is fixed inside the device outer shell 15 so as to become.

  At this time, the humidifying water tray 16 may be entirely composed of a light transmitting body, but only the facing surface of the light emitting element 4 and the light receiving element 5 is welded or bonded to the light transmitting body in a state where water leakage is prevented. May be partially configured.

  Similarly, in the configuration of the direct external light incident preventing means 14, the light receiving direction of the light receiving element 5 is not oriented in the direction of removing the humidifying water tray 16 with respect to the apparatus outer shell 15, and therefore the light receiving direction of the light receiving element 5 is the apparatus outer shell 15. Even when the humidifying water tray 16 is removed from the apparatus outer shell 15 as shown by adding an arrow in FIG. 11, the humidifying water tray 16 is detached from the apparatus outer shell 15. Since the direction and the light receiving direction of the light receiving element 5 are orthogonal, it is possible to prevent the direct incidence of extraneous light on the light receiving element 5.

  According to such a configuration, even when the container body 1 is exposed to the outside of the device with the container body 1 mounted on the device, or the container body 1 can be detached from the device, the direct reflected light shielding means 9 can be used. Therefore, it is possible to prevent direct incidence of the extraneous light on the light receiving element 5, so that the light receiving element 5 is hardly affected by extraneous light other than the irradiation light of the light emitting element 4 which is a main factor of liquid detection. Therefore, detection of the presence or absence of liquid can be stabilized.

  Further, in the method of detecting the liquid 2 from the lateral direction at the upper part of the tank lid 20 that is the lowermost part of the humidifying water tank 17 that is the container body 1, the liquid 2 as shown in FIGS. 12 to 13. Of the extraneous light including indirect light from above and from the side of the humidifying water tank 17 by disposing the light shielding member 21 in the space 3 of the humidifying water tank 17 that is the container body 1 serving as the detection position of It can also be set as the structure which interrupts | blocks incidence to the element 5. FIG.

  The light shielding body 21 is disposed on the upper portion of the tank lid 20 below the humidifying water tank 17 in a state where the humidifying water tank 17 is attached to the apparatus outer shell 15, and the tank lid 20 is removed from the humidifying water tank 17. In the removed state, it is processed so that it can be fixed at the specified position of the humidified water tank 17 by inserting it from the opening of the humidified water tank 17 and attaching the tank lid 20 to the humidified water tank 17.

  Further, a light conducting opening 22 having a size that does not hinder the detection of the liquid 2 is provided at a position opposed to the light irradiation direction of the light emitting element 4 and the light receiving direction of the light receiving element 5. The portion is configured to be substantially in contact with the inner surface 1 b of the humidified water tank 17 so that the entrance of extraneous light from the end of the light conduction opening 22 is blocked as much as possible.

  Furthermore, the water supply by the user to the humidified water tank 17 is provided by providing a plurality of water passage openings 23 provided with walls so that light does not go straight and enter the lower part of the top surface and side surface of the light shielding body 21. The supply of water to the humidifying water tray 16 during humidification is not disturbed.

  The light shield 21 is preferably made of a material that is unlikely to deteriorate or corrode against water in long-term use. For example, the light shield 21 is molded by molding using a light non-transparent colored resin material such as polyethylene or polyethylene terephthalate. It is what you create.

  According to such a configuration, even in a configuration in which a portion of the container body 1 is exposed to the outside of the device with the container body 1 mounted on the device, the light shielding body 21 disposed inside the container body 1 allows the device outer shell 15 to be Since it is possible to prevent the direct incidence of extraneous light including indirect light reflected on the surface to the light receiving element 5, the light receiving element 5 is an extraneous light other than the irradiation light of the light emitting element 4 which is a main factor of liquid detection. Since it becomes more difficult to receive the influence of light, the detection of the presence or absence of liquid can be made more stable.

  The non-contact liquid detection configuration according to the present invention does not require a wide space for placement when the device is mounted, and enables detection even if the liquid to be detected is a transparent body. This is useful as a non-contact liquid detection configuration of a machine or a dehumidifier.

DESCRIPTION OF SYMBOLS 1 Container body 2 Liquid 4 Light emitting element 5 Light receiving element 9 Direct reflection light shielding means 14 Direct external light incident prevention means 21 Light shielding body

Claims (3)

  A transparent liquid is stored inside the container provided in the equipment, and the liquid stored in the container is used to construct a unique function. A container body constituted by a light transmissive body having a refractive index greater than that of air, a light emitting element for irradiating light to the container body arranged in one direction with respect to the container body outside the container body, and the container body A light-receiving element that outputs an electrical signal that matches the intensity of the reflected light of the light, and direct reflection light that does not change depending on the presence or absence of liquid that is directly reflected on the outer surface of the container body by light emitted from the light-emitting element. Reflected light that includes direct reflected light shielding means for blocking incidence and that is incident on the light receiving element due to an increase in the amount of light transmitted at the interface between the container body and the liquid when there is no liquid inside the container body Since the strength of Contactless liquid detection structure configured to detect determine the presence or absence of liquid by determining the decrease in the strength of Shako from the change in the output signal of the light receiving element.   In the equipment configuration where the container body part is exposed to the outside of the equipment with the container body mounted on the equipment, or the container body can be attached to and detached from the equipment, external light from the outside of the equipment is directly incident on the light receiving element. 2. The non-contact liquid detection structure according to claim 1, further comprising means for preventing direct external light incidence to be prevented.   In a device configuration in which the container body part is exposed to the outside of the device with the container body mounted on the device, a light shielding body that blocks external light including indirect light from the outside of the device to the light receiving element inside the container body The non-contact liquid detection structure according to claim 1 or 2, comprising:

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