JP5566361B2 - Detection device, detection method, and hand dryer using the same - Google Patents

Description

  The present invention relates to a detection device, a detection method, and a hand drying device using the detection device for detecting that a dielectric such as a user's hand has approached.

  In conventional hand dryers (hand dryers), for example, as described in Patent Document 1, infrared light from an infrared light emitting element or the like (light emitting unit) is blocked by a user's hand, and an infrared absorbing unit (light receiving unit). The photoelectric sensor (photoelectric sensor) that detects that the user's hand has been inserted into the hand insertion portion when the infrared light reaching the portion has become below the reference value has been employed. Such a hand dryer generally drives a blower motor to dry the user's hand when the photoelectric sensor detects that the user's hand has been inserted into the hand insertion portion.

  That is, the photoelectric sensor generally includes a light emitting unit and a light receiving unit. When the light receiving unit blocks light from the light emitting unit or receives specific reflected light, the photoelectric sensor is between the light emitting unit and the light receiving unit. It detects the presence of a hand or the like, and its principle and mechanism are simple. However, the photoelectric sensor, for example, even when something other than the user's hand such as water droplets or dirt adheres to the vicinity of the light emitting unit or the light receiving unit, that is, even when the hand is not actually inserted into the hand insertion unit, “Detect” the hand and drive the blower motor to dry it.

  Further, in a hand dryer using a photoelectric sensor, in order to install the light emitting unit and the light receiving unit in the casing, at least a part of the casing must be formed of a material having optical transparency. However, since the material constituting the casing body is usually made of an opaque material, a part of the casing body facing the light emitting part and the light receiving part, which is separately formed with a light transmissive material (window part) is embedded. There is a need. However, when different members (casing body and window) are separately formed and assembled, the assembly work becomes complicated, increasing the production cost, creating steps and gaps between the members, and attaching water droplets and dirt. Easy to clean and difficult to clean.

  On the other hand, as described in Patent Document 2, for example, in a sanitary device such as a toilet device, a capacitance type human body detection sensor that detects a capacitance that changes when a user sits on a toilet seat is proposed. ing. The human body detection sensor described in Patent Document 2 includes an antenna electrode whose capacitance changes as the human body approaches, a capacitance detector that detects a change in capacitance in the antenna electrode, and a control unit. When the control unit determines that the output voltage from the capacitance detector is equal to or higher than the reference voltage, it detects that the user is approaching.

Japanese Patent No. 4105209 JP 2010-181369 A

  However, as described above, the hand dryer employing the photoelectric sensor described in Patent Document 1 has a simple principle, but even if water droplets or dirt adheres to the vicinity of the light emitting part or the light receiving part, There is a risk of malfunction as detected, and in order to avoid this, the hand dryer including the light emitting unit or the light receiving unit must be periodically cleaned. Moreover, since it is necessary to produce and integrate a casing main body and a window part separately and to ensure the waterproof sealing property between these separate members, production cost increases. Furthermore, in conventional hand dryers, photoelectric sensors are also used for the water level (drainage storage capacity) in the drain tank that stores water droplets splashed during hand drying. It was easy to adhere and it was difficult to wipe out the possibility of false detection. When drainage is full in the drain tank, it is necessary to clean it, and if it is designed to stop using the hand dryer, it can dry your hands without the risk of malfunction of the hand dryer. There is a possibility that the hand dryer cannot be used due to false detection even though there is no hindrance.

  On the other hand, the human body detection sensor described in Patent Document 2 is installed in a toilet seat of a toilet and is not employed in a hand dryer (hand dryer). In particular, in a hand dryer that dries the user's hand inserted in the hand insertion portion, the user's hands are often rubbed or squeezed together in the hand insertion portion to promote quick drying. Is not stably maintained in the hand insertion part. Therefore, in the hand dryer, when the blower motor of the hand dryer is driven based only on whether the output voltage from the capacitance detector is equal to or higher than the reference voltage, unnecessary on / off switching of the blower motor is repeated. In some cases, the blower motor sound that is intermittently switched on and off may give the user anxiety and discomfort that they may be out of order.

  Also, when the hand dryer is designed to drive the blower motor based on the output voltage from the capacitance detector, the user's hand has left the hand dryer's hand insertion part, but splashed water droplets from the user's hand will not be If it continues to adhere to the position facing the capacitance detector, the blower motor is driven in vain.

  That is, a detection device that can accurately detect that a non-stationary (non-fixed) dielectric such as a user's hand has approached a predetermined position by detecting a change in capacitance. There is a need to propose. In particular, it is determined whether the capacitance change is caused by the user's hand or splashed water droplets (including dirt), and strong against the realization of a hand dryer that drives the blower motor only when the user's hand should be dried. There is a request.

Accordingly, the present invention has been made in view of the above-described problems, and relates to a detection device for a hand drying device , which includes a first and second conductors that can be accessed by a right hand and a left hand, and a predetermined conductor. A detection unit that continuously detects capacitances (C ₁ , C ₂ ) of the first and second conductors that change with time in a period (τ) of the first conductor, A sum signal (CA) obtained by adding a predetermined coefficient (k) to the capacitance (C ₂ ) of the second conductor to the capacitance (C ₁ ); Obtained by taking the absolute value of the difference between the capacitance (C ₁ ) of _one conductor and the capacitance (C ₂ ) of the second conductor multiplied by a predetermined coefficient (k). to calculate a difference signal (CD) which is the sum signal (CA) is greater than a predetermined sum signal threshold _{(CA th),} and When the signal (CD) is smaller than a predetermined difference signal threshold (CD _th), that is, when the following expression is satisfied, and a control unit for detecting said right and left are both close to the first and second conductors It is characterized by having .

  According to the detection device according to the present invention, it is possible to accurately detect the approach. Moreover, according to the hand drying apparatus which concerns on this invention, the user's hand inserted in the hand insertion part can be detected correctly irrespective of the water droplet and dirt adhering to the casing surface.

It is a perspective view which shows the hand dryer by Embodiment 1 which concerns on this invention. (A) is the front view which looked at the casing of the hand dryer of FIG. 1 from the inner side, (b) is the side sectional view of the hand dryer which was seen from the vertical cross section of the front-back direction. It is a block circuit diagram which shows the schematic electrical circuit structure of a hand dryer. (A) And (b) is the perspective view and top view which show the groove part containing the opening part provided in the inner wall of a casing. (A) And (b) is the perspective view and top view which show the groove part by the modification of Fig.4 (a) and (b). (A) And (b) is a graph which shows the electrostatic capacitance of the conductive wire detected by the detection sensor, and a predetermined threshold value. (A) And (b) is a figure similar to FIG. 2 (a) and FIG.2 (b) of the hand dryer by the modification of Embodiment 1. FIG. (A)-(c) is an expanded sectional view which shows a part of casing containing a 2nd ventilation port. It is a flowchart which shows the operating method of the hand dryer which concerns on this invention. It is a timing chart which shows the control process (subroutine) when a control part drives a ventilation motor. (A) And (b) is a timing chart which shows the operation | movement method of the hand dryer of Embodiment 2. FIG. (A) is a graph which shows the relationship between the position of a user's hand and the electrostatic capacitance of a conductive wire in the hand dryer of Embodiment 3, (b) is a sum signal (thick solid line) and a difference signal ( A thin solid line). FIG. 10 is a perspective view showing a hand dryer according to a fourth embodiment. (A) is the front view which looked at the casing of the hand dryer of FIG. 13 from the inside, (b) is a side sectional view of the hand dryer which was seen from the vertical cross section of the front-back direction. (A) And (b) is the figure similar to FIG. 14 (a) and FIG.14 (b) of the hand dryer by the modification of Embodiment 4. FIG. (A) And (b) is the figure similar to FIG. 14 (a) and FIG.14 (b) of the hand dryer by another modification of Embodiment 4. FIG.

  Hereinafter, embodiments of a dielectric detection sensor (hereinafter simply referred to as “detection sensor” or “detection unit”) and a hand dryer (hand dryer) using the same will be described with reference to the accompanying drawings. To do. In the following description of the embodiments, terms representing directions (for example, “left-right direction” or “front-rear direction”) are used as appropriate for easy understanding. Is not intended to limit the present invention. Moreover, in each accompanying drawing, the same component is illustrated using the same referential mark.

  FIG. 1 is a perspective view showing a hand dryer 1 according to Embodiment 1 of the present invention. The hand dryer 1 is for drying a hand by applying dry air to a wet hand after the user has washed his hand. For example, the hand dryer 1 is commercially available as a registered trademark “Jet Towel” series of the present applicant. ing. The hand dryer 1 has a concave space for inserting a user's hand, that is, a casing (housing) 10 that forms a hand insertion portion 11. The hand dryer 1 also has a drain tank (drainage tank) 12 that accumulates water droplets splashed from the user's hand. Further, the hand dryer 1 includes a main body display unit 13 including a green LED lamp indicating that the hand dryer 1 is in a usable state (standby state) and a red LED lamp indicating an operation abnormality, and a drain accumulated in the drain tank 12. And a drain display unit 14 including a red LED lamp indicating that the water (drainage) is full. The drain tank 12 can be attached to and detached from the casing 10 in the direction of the arrow in FIG. 1, and the drain display unit 14 allows the user to drain the red LED lamp by lighting the red LED lamp when the drain tank 12 becomes full. It warns you to dispose of water.

  2A is a front view of the casing 10 removed from the main body of the hand dryer 1 shown in FIG. 1 as viewed from the inside (installed wall side), and FIG. It is side sectional drawing of the hand dryer 1 seen from the vertical cross section extended in parallel in the front-back direction. FIG. 3 is a block circuit diagram showing a schematic electrical circuit configuration of the hand dryer 1. The hand dryer 1 includes a blower unit 40 including a blower motor 42 for forming a dry air for drying a wet hand when a user's hand is inserted into the hand insertion unit 11, and the hand insertion unit 11. The illumination unit 50 includes an illumination lamp 52 that sterilizes and sterilizes the surface of the user's hand by irradiating the surface with ultraviolet rays, and a capacitance for detecting whether or not the user's hand is inserted into the hand insertion unit 11. And a detection sensor 20 of the type. The hand dryer 1 also includes a control unit 30 that controls the air blowing unit 40, the illumination unit 50, and the detection sensor 20, and a power supply unit 60 that supplies appropriate DC or AC power to them. The control unit 30 may be disposed on the circuit board 32 on which other electrical components constituting the hand dryer 1 are mounted (FIG. 2A).

  As the blower motor 42, any one that forms dry air to dry wet hands can be adopted. Preferably, the amount of air can be freely adjusted by controlling the rotation speed. Those are preferred. Also, the illumination lamp 52 may be any lamp widely known to those skilled in the art as long as it can irradiate light having a sterilizing / sterilizing action, and does not limit the present invention.

  As shown in FIGS. 2A and 2B, the casing 10 has a blower port 44 for guiding the dry air formed by the blower motor 42 toward the user's hand. Further, the detection sensor 20 has a pair of conductive wires 22 a and 22 b extending from the control unit 30 to the hand insertion unit 11 along the inner wall of the casing 10 through the periphery of the air blowing port 44. When operating the hand dryer 1, the user tends to move his hand to the vicinity of the air outlet 44 through which the drying air is blown in anticipation of drying early, so that the user's hand can be more easily detected. In addition, the pair of conductive wires 22 a and 22 b are preferably formed so as to surround the air outlet 44 in the manual insertion portion 11.

The conductive wires 22a, 22b may be, for example, conductive wires (electric wires, antenna wires, etc.) coated with an insulating film. The user's hand, which is a dielectric material, is inserted into the hand insertion portion 11 so that the casing 10 is removed. Any material and configuration can be adopted as long as the electric conductor changes its capacitance in a non-contact manner. In this embodiment, the detection sensor 20 is illustrated as having a pair of conductive lines, but may be configured to have a single conductive line by connecting both ends thereof.
In addition, in order to detect reliably whether a user's hand was inserted in the hand insertion part 11 irrespective of the insertion position, the conductive wires 22a and 22b are provided on the casing 10 facing the hand insertion part 11. It is preferable to be configured to cover a wider area of the inner wall.

  More specifically, as shown in FIGS. 4A and 4B, the groove portion 16 including the opening portion 15 is provided on the inner wall of the casing 10, and the outer diameter of the conductive wire 22 is equal to the width of the groove portion 16. Further, the width of the opening 15 is configured to be narrower than its outer diameter, and a relatively soft insulating film is pushed through the opening 15 so as to be arranged along the inner wall of the casing 10. . That is, the casing 10 has a protrusion 17 that assists in accommodating the conductive wire 22 in the groove 16. By configuring in this way, the arrangement position and shape of the conductive wire 22 can be made constant, and the working efficiency of the assembly can be improved. In this case, as compared with the case where the conductive wire 22 is fixed to the casing 10 using a fixing member such as an adhesive tape, an excellent effect in increasing the stray capacitance, stabilizing the arrangement position of the conductive wire 22 and reducing the number of work steps. Can be realized.

  As a modified example, instead of continuously forming the protrusion 17 constituting the opening 15 which is narrower than the outer diameter of the conductive wire 22 on the inner wall of the casing 10, FIG. 5 (a) and FIG. 5 (b). As shown, the same effects as described above can be obtained even when the signals are intermittently arranged at a plurality of positions. This modification is particularly useful when it is difficult to integrally form the protrusions 17 that extend continuously in the casing 10 but it is relatively easy to integrally form the intermittent protrusions 17. It is.

  In the hand dryer 1 configured as described above, when the user's hand is inserted into the hand insertion portion 11, the capacitance of the conductive lines 22a and 22b detected by the detection sensor 20 changes. 6A and 6B are wet after experimentally spraying mist-like water droplets into the hand insertion portion 11 with a spray sprayer (not shown) in the timing period indicated by broken lines M1 and M2 in the figure. 6 is a graph (C (t), thin solid line) showing a change with time of the capacitance of the conductive wire 22a on the right hand side detected by the detection sensor 20 when a hand (right hand) is inserted. The detection sensor 20 may detect a capacitance digital signal indicating the capacitance of the conductive wire 22a when the sampling frequency is 100 Hz, for example. At this time, the sampling interval (τ) is 10 ms.

For example, the control unit 30 continuously calculates a moving average value (A (t)) of 100 times the sampling interval (τ), that is, the past one second (= 100 × 10 ms). That is, the control unit 30 calculates the moving average value of the capacitance (A (t), broken line in FIG. 6A) in a predetermined period (nτ: n is a natural number of 2 or more) with the predetermined time point as an end point. calculate. That is, the moving average value (A (t)) can be calculated by the following equation.

  Although not described in detail, the detection sensor 20 according to the present invention detects an analog signal indicating the capacitance of each of the conductive lines 22a and 22b that is changed by a dielectric such as a user's hand inserted into the hand insertion portion 11. Then, the control unit 30 may calculate the average value of the capacitance by time-integrating the capacitance analog signal and dividing it by the unit time, or by using a low-pass filter circuit (not shown). An average value signal of capacitance may be output.

Then, the control unit 30 determines the difference (D (t) = C (t) −A (t) between the capacitance (C (t)) and the moving average value (A (t)) in FIG. (Thick solid line). Further, when the control unit 30 determines that the difference (D (t)) is larger than a predetermined casing threshold (casing capacitance difference threshold, D _th ), that is, when the following equation is satisfied, the user's hand is manually inserted. It is determined that it has been inserted into the section 11.

  When it is determined that the user's hand has been inserted into the hand insertion unit 11, the control unit 30 controls the blower unit 40 to drive the blower motor 42. Then, the drying air is blown to the user's hand from the air blowing port 44 of the casing 10, and the user's hand can be dried.

For example, when the hand dryer 1 is installed in a frequently used place, it is blown off by dry air from many users' hands, as in the case where a mist water droplet is experimentally sprayed into the hand insertion unit 11 with a spray sprayer. The splashed water droplets adhere to the outer surface of the casing 10 of the hand dryer 1. Then, the electrostatic capacitance (C (t)) of the conductive wire 22 detected by the detection sensor 20 is a ferroelectric material attached to the casing 10 even before the user's hand is inserted into the hand insertion portion 11. It will be maintained at a high level due to the splashed water droplets. That is, in the hand dryer 1 using the capacitance type detection sensor 20, an increase in the capacitance (C (t)) due to the splashed water droplets is planned in advance, and is indicated by a one-dot chain line in FIG. 6B. The casing threshold value (C _th 1) must be set large.

However, if the casing threshold value (C _th 1) is set large, conversely, when the water droplets are not attached to the outer surface of the casing 10 of the hand dryer 1 and are dry, the capacitance of the conductive wire 22 The hand dryer 1 cannot be operated unless both hands are sufficiently inserted into the hand insertion portion 11 such that the casing threshold value (C _th 1) exceeds a high level. If the outer surface of the casing 10 is dry, for example, if the user wants to dry only the fingertip, setting a high level casing threshold (C _th 1) will cause the hand dryer 1 to not operate and inconvenience the user. There is. That is, when water droplets are not attached to the outer surface of the casing 10, in order to detect the user's hand with higher accuracy, the casing threshold value (C _th 2) indicated by another alternate long and short dash line in FIG. It is necessary to set so small.

In view of such a problem, the detection sensor 20 (control unit 30) according to Embodiment 1 determines the difference (D (t) between the capacitance (C (t)) and the moving average value (A (t)). 6), and the difference is compared with the casing threshold value (D _th ), so that the above description is made regardless of the amount of water droplets adhering to the outer surface of the casing 10. The casing threshold value (D _th ) can be set smaller than the casing threshold value (C _th 1, C _th 2). Therefore, the detection sensor 20 according to the first embodiment uses the smaller casing threshold (D _th , the alternate long and short dash line shown in FIG. 6A) regardless of the amount of water droplets attached to the outer surface of the casing 10. It is possible to more accurately detect that the hand is inserted into the hand insertion portion 11.

  As described above, the moving average value (A (t)) depends on both the user's hand inserted into the hand insertion portion 11 and the splashed water droplets attached to the outer surface of the casing 10 of the hand dryer 1. Therefore, when the user's hand is not inserted into the hand insertion portion 11, the moving average value (A (t)) depends only on the environment such as splashed water droplets adhering to the outer surface of the casing 10. Is. Therefore, in this context, the moving average value (A (t)) when the user's hand is not inserted into the hand insertion unit 11 can also be referred to as an “environmental noise component”.

Since the outer surface of the casing 10 is usually made of a material having an antibacterial / water repellent function, when the hand dryer 1 is not used, splashed water droplets or the like adhering to the outer surface can be drained in a relatively short time. It is collected in the tank 12. However, when dirt or foreign matter adheres continuously in the hand insertion portion 11, the environmental noise component is maintained at a high level. In such a case, the user should be informed that the outer surface of the casing 10 needs to be cleaned and prompted to clean it.
Therefore, the control unit 30 according to the present invention has a conductive line noise threshold value (indicated by a two-dot chain line in FIG. 6A) of the environmental noise component (that is, the moving average value) over a relatively long predetermined time (for example, 10 minutes). When maintained at a level higher than the conductive line background threshold (A _th ), that is, when the following expression is satisfied, it is determined that dirt or foreign matter is adhered to the outer surface of the casing 10.

  At this time, in order to notify the user that dirt or foreign matter is attached to the outer surface of the casing 10, the control unit 30 turns on the red LED lamp instead of the green LED lamp of the main body display unit 13. The display unit 13 is controlled. Thus, according to the hand dryer 1 according to the present invention, the casing 10 can always be kept clean by prompting the user to remove dirt or foreign matter adhering to the outer surface of the casing 10 and cleaning the casing 10. .

In addition to this, when the control unit 30 determines that the environmental noise component is higher than the conductive wire noise threshold value (A _th ) for a predetermined time or longer, the control unit 30 does not drive the blower motor 42 so that the hand dryer 1 is not clean. You may make it prohibit use of. In this embodiment, the main body display unit 13 visually notifies the user of the operating state (normal or abnormal state) using an LED lamp or the like. You may do.

  Although the casing 10 is assumed to have a single air outlet 44 in the above description, as shown in FIGS. 7 (a) and 7 (b), the drying air from the air blowing motor 42 is applied to the outer surface of the casing 10. Another air outlet 46 for direct guidance may be provided, and splashed water droplets adhering to the outer surface of the casing 10 may be positively removed. That is, the casing 10 is formed on the outer wall of the casing 10 facing the first air outlet 44 and the conductive wires 22a and 22b for supplying the dry air from the air blowing motor 42 toward the user's hand in the hand insertion portion 11. And a second air blowing port 46 for supplying the water droplets along the water, and the water droplets adhering to the outer surface of the casing 10 are efficiently guided to the drain tank 12 by the dry air supplied from the second air blowing port 46. Thus, the environmental noise component can be kept small.

  As long as the 2nd ventilation port 46 of the casing 10 supplies a dry wind along the outer wall of the casing 10 (in the direction substantially parallel to the outer wall of the casing 10), arbitrary forms are employable. FIGS. 8A to 8C are cross-sectional views showing a part of the casing 10 including the second air blowing port 46. The casing 10 shown in FIGS. 8A and 8B has first and second inclined portions 18a and 18b that overlap each other, and the second air blowing port 46 is between these inclined portions 18a and 18b. Is formed. Further, the casing 10 shown in FIG. 8C has a substantially L-shaped dry air guide tube 19 inserted into a through-hole extending perpendicularly thereto, whereby a second blower port 46 is formed. Yes. In any case, splashed water droplets from the user's hand or the like are configured not to enter the casing 10 via the second air blowing port 46.

  In other words, the water repellent effect of the outer surface of the casing 10 is supported, and the conductive wires 22a and 22b are attached to the outer surface of the facing casing 10 by the dry air supplied from the second blower port 46 as described above. If the water droplets can be sufficiently removed during the operation of the blower motor 42, the control unit 30 does not need to calculate the moving average value (A (t)), and the detected capacitance of the conductive wire 22 (C Whether or not the user's hand has been inserted into the hand insertion unit 11 can also be determined based on whether or not (t)) exceeds a predetermined threshold (not shown).

Furthermore, as shown in FIGS. 2 and 3, the detection sensor 20 according to the first embodiment includes a drain conductive plate 24 that is electrically connected to the control unit 30 and disposed opposite the drain tank 12. The drain conductive plate 24 may be, for example, a strip-shaped tin-plated steel plate. The drain conductive plate 24 may have any shape and size as long as the capacitance changes depending on the amount of drainage (drain water amount) accumulated in the drain tank 12. The detection sensor 20 according to the first embodiment detects the capacitance (E (t)) of the drain conductive plate 24 as well as the capacitance (C (t)) of the conductive wire 22. Then, the control unit 30 calculates a moving average value (F (t)) of the capacitance (E (t)) of the drain conductive plate 24 and a difference (G (t)) between them, and this is a predetermined drain. When it is determined that it is greater than the threshold (drain capacitance difference threshold, G _th ), that is, when the following equation is satisfied, it is determined that the wastewater accumulated in the drain tank 12 is full.

  At this time, the control unit 30 turns on the drain display unit (red LED lamp) 14 to notify the user that the drain tank 12 is full of water (exceeding a predetermined water level). The user can be alerted to remove from the casing 10 and dispose of the drain water. In this embodiment, the drain display unit 14 informs the user whether or not the drain tank 12 is full. However, the drain level accumulated in the drain tank 12 is continuously increased. It may be something that informs. The drain display unit 14 visually notifies the user of the water level in the drain tank 12, but may notify the user audibly by an alarm sound or the like, for example. Thus, when the drain tank 12 is full, the drain tank 12 is removed from the casing 10, and the drain tank 12 is kept clean by prompting the user to discard the drainage accumulated in the drain tank 12. be able to.

The control unit 30 determines that the electrostatic capacity (E (t)) itself, not the moving average value (F (t)) of the electrostatic capacity (E (t)) of the drain conductive plate 24, has a predetermined threshold for this. It can also be determined whether or not the drainage in the drain tank 12 is full depending on whether or not it has exceeded. However, since the electrostatic capacity (E (t)) of the drain conductive plate 24 is disposed relatively adjacent to the hand insertion portion 11, when the user uses the hand dryer 1, Increased by the inserted user's hand or by a body other than the user's hand approaching the hand dryer 1 (for example, the user's torso), temporarily exceeds the drain threshold, and the drainage in the drain tank 12 is full. May be mistakenly determined. Therefore, as described above, the control unit 30 has a difference (G (t)) between the capacitance (E (t)) of the drain conductive plate 24 and the moving average value (F (t)) to some extent. It is more preferable to determine that the drainage in the drain tank 12 is full when it is larger than a predetermined capacitance difference threshold (G _th ) over a long predetermined period (for example, 1 minute).

  As described above, in order to suppress as much as possible the increase in the electrostatic capacity (E (t)) of the drain conductive plate 24 caused by things other than the drainage accumulated in the drain tank 12, it is preferable to connect the drain tank 12 and the hand. A shield plate (not shown) made of a conductive material grounded between the insertion portion 11 and the front surface of the drain tank 12 is disposed.

  The detection sensor 20 according to the present invention can be used alone as a detection device for detecting the approach of a dielectric. In that case, the calculation of the moving average value described above, comparison determination with various threshold values, etc. Needless to say, it is necessary to provide a dedicated control unit (not shown) separate from the control unit 30 of the hand dryer 1.

Next, an actual operation method of the hand dryer 1 (the detection sensor 20 and the control unit 30) will be described below with reference to the flowchart of FIG.
First, in step ST01 of FIG. 9, the user turns on the power switch 62, supplies AC power to the power supply unit 60, and initializes the hand dryer 1.

  In step ST02, the detection sensor 20 detects the electrostatic capacitance (E (t)) of the drain conductive plate 24. In step ST03, the control unit 30 continuously calculates the moving average value (F (t)) for a predetermined period. To calculate.

In step ST04, the control unit 30 determines the difference (movement) between the current capacitance (E (t)) of the drain conductive plate 24 and the moving average value (F (t)) for a certain past period (for example, 1 minute). An average value difference (G (t)) is calculated, and it is determined whether this is greater than a predetermined drain threshold (G _th ), that is, whether the following equation is satisfied.

  In the case of YES in step ST04, the control unit 30 determines that the drainage accumulated in the drain tank 12 is full (the drain tank 12 is in an abnormal state), and turns on the drain display unit 14 in step ST05. The user is warned to remove the drain tank 12 from the casing 10 and discard the drain water. At this time, although not essential in the present invention, the control unit 30 controls that the blower 40 and the like do not operate so as to stop the use of the hand dryer 1 on the assumption that drain water needs to be cleaned such as disposal. Also good.

  In the case of NO in step ST04 (when the drain tank 12 is in a normal state), in step ST06, the detection sensor 20 detects the electrostatic capacity (C (C () of the pair of conductive wires 22a and 22b arranged along the inner wall of the casing 10). t)) is detected, and in step ST07, the control unit 30 continuously calculates the moving average value (A (t)) for a predetermined period.

In step ST08, the control unit 30 determines the difference between the capacitance (C (t)) of each of the conductive lines 22a and 22b and the moving average value (A (t)) for a predetermined period (moving average value difference, D ( t)) is calculated, and it is determined whether this is larger than a predetermined casing threshold (D _th ), that is, whether the following equation is satisfied.

  In the case of YES in step ST08, the control unit 30 determines that the user's hand has been inserted into the hand insertion unit 11, proceeds to step A in FIG. 9, and controls the blower unit 40 to drive the blower motor 42. To do. Thus, the drying air is blown from the blower opening 44 of the casing 10 to the user's hand, and the user's wet hand can be dried.

Here, a subroutine (from step “A” to step “B”) showing a specific control process when the control unit 30 drives the blower motor 42 will be described with reference to the timing chart of FIG. FIG. 10A schematically shows a difference (D (t), hereinafter simply referred to as “moving average value difference”) and a casing threshold value (D _th ) indicated by a thick solid line in FIG. FIG. 10B shows a period during which the control unit 30 determines that the user's hand is inserted into the hand insertion unit 11, and FIG. 10C shows a period during which the blower motor 42 is driven by the control unit 30. It is a timing chart. The detection sensor 20 according to the first embodiment has a pair of left and right conductive wires 22a and 22b, but will be described below as having a single conductive wire 22 for convenience of explanation.

In the timing chart of FIG. 10, when the time that the moving average value difference, D (t) satisfies the conditional expression [6] exceeds a predetermined delay time (T ₁ ), the control unit 30 moves the user's hand. It is determined that it has been inserted into the insertion unit 11 (ON determination). The reason for providing the delay time (T ₁ ) in this way is that, as shown in FIG. This is to prevent erroneous recognition. The control unit 30 controls the blower 40 so as to drive the blower motor 42 immediately after reliably detecting the user's hand. However, since a slight time difference may occur between the ON determination of the control unit 30 and the time when the blower motor 42 is actually driven and the drying air is supplied to the user's hand, this is the delay time (T ₂ ). It expresses.

  In general, the hand dryer 1 is for drying the user's hand, and the user may rub and squeeze both hands in the hand insertion portion 11 in order to promote quick drying. At this time, the moving average value difference (D (t)) fluctuates as shown in FIG. 10A, and the control unit 30 determines whether or not the control unit 30 is ON based only on whether or not the conditional expression [6] is satisfied. If it is determined to be OFF, the blower motor 42 is intermittently driven, and operations such as sliding of both hands cannot be performed, resulting in inconvenience to the user, and furthermore, the blower motor 42 is intermittently driven. This gives anxiety and discomfort that the hand dryer 1 may be out of order.

Therefore, the control unit 30 only when the period (ΔT) in which the conditional expression [6] is not satisfied with respect to the moving average value difference (D (t)) exceeds the predetermined delay time (T ₃ ) (ΔT> T ₃ ), It is determined that the user's hand has detached from the hand insertion unit 11 (OFF determination), and when the period (ΔT) is smaller than the delay time (T ₃ ) (ΔT <T ₃ ), the ON determination is maintained. Note that a slight time difference may occur between the time when the control unit 30 is turned off and the time when the driving of the blower motor 42 is actually stopped. This is expressed as a delay time (T ₄ ).
According to the hand dryer 1 configured as described above, even if the user slides or squeezes his / her hand in the hand insertion portion 11, the blower motor 42 does not stop intermittently and comfortably and quickly. Hands can be dried.

In this control process, when it is determined that the user's hand has left the hand insertion unit 11 (OFF determination), that is, when a series of operations shown in the timing chart of FIG. 10 is completed, the process returns to Step B of the flowchart of FIG. Then, the operation process from step ST09 is continued.
Similarly, in the case of NO in step ST08 of this flowchart, the process proceeds to step ST09. Then, the control unit 30 determines whether dirt or foreign matter is continuously adhered in the manual insertion unit 11. That is, the control unit 30 determines whether or not the environmental noise component (moving average value (A (t))) is maintained at a level higher than the conductive line noise threshold (A _th ) for a predetermined period (for example, 10 minutes) or longer. If the following expression is satisfied, it is determined that dirt or foreign matter is attached to the outer surface of the casing 10.

When it is determined that dirt or foreign matter is attached to the outer surface of casing 10 (YES in step ST09), control unit 30 turns on the red LED lamp of main body display unit 13 in step ST10, and The casing 10 can always be kept clean by informing the user of the fact and cleaning it.
Similarly, although not indispensable in the present invention, the control unit 30 determines that the surface of the casing 10 needs to be cleaned in step ST10, so that the blower motor 42 does not operate to stop using the hand dryer 1. The unit 40 may be controlled.
In addition, as described above, the casing 10 supplies the dry air from the blower motor 42 along the outer wall of the casing 10, and the dedicated second blower for efficiently removing splashed water droplets from the outer surface of the casing 10. It may have a mouth 46.

Embodiment 2. FIG.
A second embodiment of the hand dryer according to the present invention will be described with reference to FIG. The hand dryer 1 according to the second embodiment is different from the hand dryer according to the first embodiment except that the method of determining whether the user's hand is inserted into the hand insertion unit 11 is different from the ON / OFF determination method of the control unit 30. 1 has the same configuration as that of FIG.

As in the first embodiment, the detection sensor 20 according to the second embodiment includes a pair of left and right conductive wires 22a and 22b and a drain conductive plate 24, each having a capacitance (C (t), E (t)). And moving average values (A (t), F (t)) for a predetermined period are calculated.
The invention according to the second embodiment can be applied to the pair of left and right conductive wires 22a and 22b and the drain conductive plate 24. However, in order to facilitate understanding, only one of the conductive wires 22 (arranged on the right side) is used. The ON / OFF determination method of the control unit 30 will be described below.

  The detection sensor 20 of Embodiment 2 detects the electrostatic capacitance (C (t)) of the conductive wire 22, and the control unit 30 calculates the moving average value (A (t)). FIG. 11A shows the capacitance (C (t)) of the conductive wire 22 detected when the user's hand is inserted into the hand insertion unit 11 and maintained for a while and then detached. It is the graph which plotted roughly the moving average value (A (t)) continuously calculated about.

Although the capacitance (C (t)) and the moving average value (A (t)) are momentarily as shown in FIG. 11A, the control unit 30 of the second embodiment uses a memory (not shown) The moving average value (A (t)) that changes with time is stored using the storage means. Then, the control unit 30 has a first moving average value (A (t ₁ )) in a predetermined period before a certain time point (for example, 0.5 seconds which is 50 times the sampling interval (τ = 10 ms)), A difference (DA (t)) from the second moving average value (A (t ₂ )) at a predetermined time after that time is calculated. Then, the control unit 30 of the second embodiment makes an ON determination when the difference (DA (t)) is larger than a predetermined average difference threshold value (DA _th ) and is a positive value (when increased), When it is a negative value (decrease), it is judged OFF. That is, the control unit 30 determines whether or not the user's hand has been inserted into the hand insertion unit 11 and whether or not the user's hand has detached from the hand insertion unit 11 (ON / OFF determination) by the following equation.

FIG. 11B is a graph similar to FIG. 11A showing a modification according to the second embodiment. In this modified example, the control unit 30 sets the period when calculating the moving average value (A (t)) to a relatively long constant period of, for example, 0.5 seconds, and the first and second The ON / OFF determination may be made by partially overlapping the calculation periods of the moving average values (A (t ₁ ), A (t ₂ )). That is, two different time points (t _p , t _q , and the time difference thereof is set to Δt (= t _q −t _p )) are set, and the first time point with the first time point (t _p ) as the end point is set. a first moving average value a _{(t p),} the difference between the second moving average value a in the second period in which the second time point _{(t q)} and end point _{(t p) (DA (t} )) _{May be} determined to be ON when it is larger than a predetermined average difference threshold (DA _th ) and is a positive value (increase), and OFF may be determined when it is a negative value (decrease). That is, the control unit 30 determines whether or not the user's hand has been inserted into the hand insertion unit 11 and whether or not the user's hand has detached from the hand insertion unit 11 (ON / OFF determination) by the following equation.

At this time, it is preferable that the calculation period of the first and second moving average values (A (t _p ), A (t _q )) can be arbitrarily set. In addition, even after the user's hand is detached from the hand insertion portion 11, the splashed water droplets tend to adhere to the outer wall of the casing 10. Therefore, the average difference threshold (DA _th−ON ) for determining _ON is determined as OFF. It is preferable to set it larger than the average difference threshold (DA _th−OFF ).

Furthermore, the time difference Δt between the two time points (t _p , t _q ) can be made extremely small by reducing the sampling interval (τ). At this time, when the time differential coefficient of the moving average value A (t) is larger than the positive average difference threshold value (DA _th ), the control unit 30 detects that the user's hand has been inserted into the hand insertion unit 11 (ON determination) Then, when the time differential coefficient of the moving average value A (t) is larger than the negative average difference threshold value (DA _th ), it may be detected that the user's hand has left the hand insertion unit 11 (OFF determination).

  Note that the control unit 30 according to the second embodiment has been described as determining ON / OFF independently of the first embodiment, but in addition to performing the ON / OFF determination as described in the first embodiment. In addition, the ON / OFF determination method according to the second embodiment may be adopted to improve the detection accuracy regarding whether or not the user's hand has been inserted into the hand insertion unit 11.

Embodiment 3 FIG.
Embodiment 3 of the hand dryer according to the present invention will be described with reference to FIG. The hand dryer 1 according to the third embodiment drives the blower motor 42 (use of the hand dryer 1) only when the control unit 30 determines that both hands of the user have been inserted into the hand insertion unit 11. Since the configuration is the same as that of Embodiment 1 or 2 except that the above is permitted, the description of the overlapping contents is omitted.

  Generally, in a medical field such as a surgical operation, a surgeon or the like needs to clean and dry both hands in order to prevent infection. The hand dryer 1 according to the third embodiment can be used as a hand dryer only when it is determined that both hands of the user are securely inserted into the hand insertion portion 11.

As described above, the hand dryer 1 has the left conductive line 22a and the right conductive line 22b arranged on the left and right with respect to the user, and the left conductive line 22a and the right conductive line 22b are connected to the control unit 30. , Extending from the periphery of the air blowing port 44 to the hand insertion portion 11 along the inner wall of the casing 10. FIG. 12A shows the position and detection of the user's hand when one hand of the user is gradually shifted from the left end of the hand insertion portion 11 toward the right end (both not shown). The capacitance of the left conductive line 22a detected by the sensor 20 (C ₁ , thick solid line) and the capacitance of the right conductive line 22b (C ₂ , thin solid line) are plotted. The unit of capacitance is a relative value output from the detection sensor 20, and the position of the hand corresponds to the distance from the left end of the hand insertion portion 11.

However, the length of the left conductive wire 22a and the right conductive wire 22b from the control unit 30 is different in the hand dryer 1 used for obtaining the graph of FIG. 12A (FIGS. 2A and 2B). Since the sensitivity of the capacitance detected by each of the conductive lines 22a and 22b varies, the sensitivity that can be set with respect to the capacitance (C ₂ ) of the right conductive line 22b so that the respective peak values are equal. The result of multiplication by the coefficient (k) is plotted.
The control unit 30 is arranged as centrally as possible, and the left conductive wire 22a and the right conductive wire 22b are designed to have the same dimensions (length, diameter, etc.) and electrical characteristics (capacitance, resistance value, etc.). -It is desirable to fabricate and make the sensitivity coefficient (k) equal to 1.

As apparent from FIG. 12A, when the user gradually shifts his / her position from the left end of the hand insertion portion 11 to the right, the capacitance (C ₁ ) of the left conductive line 22a increases. The peak (maximum value) is reached, and the capacitance (C ₂ ) of the right conductive line 22b increases and reaches the peak (maximum value). The peak positions of the capacitances (C ₁ , C ₂ ) of the left conductive line 22a and the right conductive line 22b differ depending on the position of the user who is a dielectric. That is, the position of the user's hand can be estimated from the electrostatic capacitances (C ₁ , C ₂ ) of the left conductive line 22a and the right conductive line 22b. When inserted in the position (center position), the capacitances (C ₁ , C ₂ ) of the left conductive line 22a and the right conductive line 22b simultaneously reach a peak.

That is, according to the third embodiment, the detection sensor 20 continuously detects the electrostatic capacitances (C ₁ , C ₂ ) of the left conductive line 22a and the right conductive line 22b, and the control unit 30 is represented by the following equation: The sum signal (CA) obtained by adding the capacitance (C ₂ ) of the right conductive wire 22b multiplied by the predetermined sensitivity coefficient (k) to the capacitance (C ₁ ) of the left conductive wire 22a. When the calculated sum signal (CA) is greater than a predetermined sum signal threshold value (CA _th ), that is, when the following equation is satisfied, at least one of the left hand and right hand of the user is applied to the left conductive line 22a or the right conductive line 22b. It is comprised so that it may detect as approaching.

Further, in addition to the conditional expression [10], the control unit 30 adds the predetermined coefficient (k) from the capacitance (C ₁ ) of the left conductive line 22a to the right conductive line 22b. The difference signal (CD) obtained by taking the absolute value of the value obtained by subtracting the capacitance (C ₂ ) is calculated. When the difference signal (CD) is smaller than a predetermined difference signal threshold (CD _th ), that is, When satisfy | filling, it detects that both the user's hands approached the left side conductive wire 22a and the right side conductive wire 22b, and controls the ventilation part 40 so that the ventilation motor 42 may be driven.

  FIG. 12B shows a sum signal (CA, thick solid line) when the position of one hand of the user is gradually shifted from the left end of the hand insertion portion 11 toward the right end (both not shown). And the difference signal (CD, thin solid line) are plotted. As is clear from FIG. 12 (b), when both hands of the user are inserted at the appropriate position (center position) of the hand insertion portion 11, the sum signal (CA) has a maximum value and a difference. The signal (CD) has a minimum value.

The sum signal (CA) and difference signal (CD) and the sensitivity coefficient (k) can be arbitrarily set according to the structure and dimensions of the detection sensor employed in the hand dryer 1. When comparing the signal threshold value (CA _th ) and the difference signal threshold value (CD _th ), the user's hands are inserted at the center position of the hand insertion unit 11 after multiplication by an arbitrary gain coefficient (g) as in the following equation: You may judge whether it was done.

  At this time, as described with reference to the timing chart of FIG. 10, the control unit 30 determines that the time satisfying the conditional expressions [10] and [11] exceeds a predetermined delay time (T, not shown). The user's both hands may be determined to have been inserted into the hand insertion portion 11.

  As described above, the hand dryer 1 according to the third embodiment is configured to permit the driving of the blower motor 42 only when the control unit 30 determines that both hands of the user have been inserted into the hand insertion unit 11. Therefore, both hands of the user can be surely dried.

Embodiment 4 FIG.
Embodiment 4 of the hand dryer according to the present invention will be described with reference to FIGS. The hand dryer 2 according to the fourth embodiment is marketed by the applicant of the present application as a “slim” series of double-sided jet wind type, and the basic configuration is the same as that described in the above embodiment. Explanation of overlapping contents is omitted.

  FIG. 13 is a perspective view showing the hand dryer 2 according to the fourth embodiment. FIGS. 14A and 14B are viewed from a vertical cross section extending in parallel with the hand dryer 2 in the left-right direction and the front-rear direction. It is sectional drawing. The casing 10 of the hand dryer 2 according to the fourth embodiment is roughly composed of a front flange (front projecting part, projecting part far from the user) 72 and a rear flange (rear projecting part, Overhang portion 74 closer to the user is provided, and hand insertion portion 11 is formed therebetween. Similar to the hand dryer 1 according to the first to third embodiments, the hand dryer 2 includes a capacitance type detection sensor 20 for detecting whether or not a user's hand has been inserted into the hand insertion unit 11, A blower 40 including a blower motor 42 for forming a dry air for drying the wet hand of the user inserted into the insertion part 11, and the user's hand by irradiating the hand insertion part 11 with ultraviolet rays And an illuminating section 50 (see FIG. 3) including an illuminating lamp for sterilizing and sterilizing the surface of the apparatus. The electric circuit configuration of the air blower 40, the illumination unit 50, the detection sensor 20, and the control unit 30 of the hand dryer 2 is the same as that of the first embodiment. Further, the hand dryer 2 has a detachable drain tank 12 similar to the above embodiment.

  In particular, the hand dryer 2 according to the fourth embodiment has the air outlets 44a and 44b in each of the front flange 72 and the rear flange 74 of the casing 10, and the air dryer 42 from the air motor 42 as shown by the arrows in FIG. The drying air to be blown is configured to be guided from the blowing ports 44a and 44b toward both the palm of the user and the back of the hand through the air passages formed in the front flange 72 and the rear flange 74. .

  In addition, the conductive wires 22a and 22b of the detection sensor 20 according to the fourth embodiment are arranged along the inner wall of only the front flange 72 of the casing 10 from the control unit 30, and are formed so as to surround the air outlet 44a. , Making it easier to detect the user's hand. The conductive wires 22a and 22b are preferably conductive wires coated with an insulating film, and any conductive material can be used as long as it is a conductor that changes its capacitance when the user's hand is inserted into the hand insertion portion 11. A configuration can be employed. In FIG. 14A, the conductive lines 22a and 22b are illustrated as having a simple rectangular planar shape. However, the conductive lines 22a and 22b may have a shape as shown in FIG. For example, it may have a zigzag shape or a spiral shape (not shown) so as to cover a wider area of the inner wall of the front flange 72 of the casing 10 facing the insertion portion 11.

  Further, as shown in FIGS. 16A and 16B, the casing 10 includes first air outlets 44 a for supplying dry air from the air blowing motor 42 toward the user's hand in the hand insertion portion 11. 44b and second air blowing ports 46a and 46b for supplying the conductive wires 22a and 22b along the outer wall of the casing 10 facing each other. The dry air supplied from the second air blowing ports 46 a and 46 b efficiently induces water droplets attached to the outer surface of the casing 10 to the drain tank 12. Thereby, a change in electrostatic capacitance (environmental noise component) due to water droplets adhering to the outer surface of the casing 10 is reduced, and the detection sensor 20 more reliably determines whether or not the user's hand has been inserted into the hand insertion portion 11. Can be detected.

  That is, the water repellent effect of the outer surface of the casing 10 is improved, and the water droplets adhering to the outer surface of the casing 10 facing the conductive wires 22a and 22b by the dry air supplied from the second air blowing ports 46a and 46b are blown motors. If it can be sufficiently eliminated during the operation of 42, the control unit 30 does not need to calculate the moving average value (A (t)), and the detected capacitance (C (t)) of the conductive wire 22. It can also be determined whether or not the user's hand has been inserted into the hand insertion unit 11 based on whether or not the value exceeds a predetermined threshold (not shown).

  By the way, in the "jet towel" series hand dryer 1 according to the first to third embodiments, the user needs to protrude both hands forward toward the hand insertion portion 11 during use. A relatively sufficient distance is maintained between the body and the like and the conductive wires 22 a and 22 b disposed along the inner wall of the casing 10. On the other hand, in the “slim” series of hand dryers 2, the user inserts both hands downward into the hand insertion portion 11 arranged at a position close to a part of his body (torso). The distance between the conductor lines 22a and 22b arranged along the inner wall of the front flange 72 and the user's body etc. approaches the rear flange 74, and the hand dryer according to the first to third embodiments. Shorter than one. At this time, since the detection sensor 20 according to the hand dryer 2 has a larger electrostatic capacity of the user's torso or the like than the hand, it is more greatly affected by the electrostatic capacity generated in the conductive wires 22a and 22b. Therefore, as shown in FIG. 16B, the hand dryer 2 according to the fourth embodiment includes a grounded conductive shield plate 76 along the inner wall of the rear flange 74 of the casing 10 to which the user's body approaches. It is preferable. Thereby, the detection sensor 20 according to the hand dryer 2 suppresses the change in capacitance due to the user's torso as much as possible, and more accurately detects whether or not the user's hand has been inserted into the hand insertion portion 11. Can do.

DESCRIPTION OF SYMBOLS 1, 2 ... Hand dryer, 10 ... Casing (casing), 11 ... Hand insertion part, 12 ... Drain tank (drainage tank), 13 ... Main body display part, 14 ... Drain display part, 15 ... Opening part, 16 ... Groove part , 17 ... Protruding part, 18 ... Inclined part, 19 ... Dry air guide tube, 20 ... Detection sensor, 22 ... Conductive wire, 24 ... Drain conductive plate, 30 ... Control part, 32 ... Circuit board, 40 ... Blower part, 42 ... Blower motor, 44,46 ... Blower, 52 ... Light, 50 ... Light, 52 ... Light, 60 ... Power supply, 72 ... Front flange (front overhang), 74 ... Rear flange (back tension) Departure).

Claims (6)

A detection device for a hand dryer,
First and second conductors accessible to the right and left hands ;
In Jo Tokoro period (tau), a detector for continuously detecting the time-varying first and second capacitance conductors _{(C 1,} C _2),
Over the previous SL capacitance of the first conductor (C _1), obtained by adding multiplied by the predetermined coefficient (k) to the capacitance of the second conductor (C ₂₎ the sum signal (CA), and the capacitance of the first conductor (C _1), the electrostatic capacitance of the second conductor (C ₂₎ to the multiplied by a predetermined coefficient (k) The difference signal (CD) obtained by taking the absolute value of the difference is calculated, the sum signal (CA) is larger than a predetermined sum signal threshold value (CA _th ), and the difference signal (CD) is a predetermined difference signal. is smaller than the threshold value (CD _th), that is, when the following expression is satisfied, detecting device, characterized in that the right and left are both a control unit for detecting the approaching the first and second conductors .

A hand dryer using the detection device according to claim 1 ,
A casing having an air outlet and a manual insertion portion;
A blower for supplying dry air from the blower opening to the manual insertion part,
The detection device is disposed in the casing;
It said first and second conductor comprises a conductive wire that is insulating coating disposed within the casing adjacent to the hand insertion portion,
Wherein, when the right and left hand is detected that both approaching the first and second conductors, to detect the hand of both the user is inserted into the hand insertion portion, from the air blowing port The air dryer is controlled so as to supply dry air to the hand insertion part. The hand dryer according to claim 2 ,
The casing has a front projecting portion and a rear projecting portion,
Conductive wires are disposed in the front overhanging portion of the casing,
A grounded shield plate is disposed in the rear projecting portion of the casing, and the electrical conductivity caused by a part of the user's body other than the hand inserted in the hand insertion portion approaching the conductive wire. A hand-drying device characterized by suppressing fluctuations in the capacitance of the wire. The hand dryer according to claim 2 ,
Further comprising a main display unit disposed in the casing,
Wherein, when said moving average value of the capacitance of the conductive lines (C (t)) (A (t)) is higher than the conductive wire background threshold continues over a predetermined period (A _th), i.e. the following formula When satisfy | filling, it detects that the dirt or the foreign material has adhered to the said casing, and controls the said main body display part to notify this to a user, The hand dryer characterized by the above-mentioned.

The hand dryer according to claim 2 ,
A drainage tank disposed below the casing;
A drainage indicator disposed in the drainage tank,
The detection device is disposed in the casing;
The conductor includes a drain conductive plate disposed in the casing adjacent to the drain tank,
The detection unit continuously detects the capacitance (E (t)) of the drain conductive plate that changes over time,
The control unit calculates a moving average value (F (t)) of the capacitance in a predetermined period (nτ: n is a natural number of 2 or more) having a predetermined time point (t) as an end point, and the capacitance ( E (t)) and the moving average value (F (t)) are accumulated in the drainage tank when the difference (G (t)) is larger than a predetermined drain threshold (G _th ), that is, when the following equation is satisfied. hand drying apparatus has been drained is detected that exceeds a predetermined level, and controls the water discharge display unit so as to notify this to the user.

A detection method for a hand dryer,
Placing first and second conductors accessible to the right and left hands;
In Jo Tokoro period (tau), the steps of continuously detecting a time-varying first and second capacitance conductors _{(C 1,} C _2),
Sum to the latent electrostatic capacitance of the first conductor (C _1), obtained by the electrostatic capacitance of the second conductor (C ₂₎ was added multiplied by the predetermined coefficient (k) the difference between the signal (CA), and the capacitance of the first conductor (C _1), and multiplied by the predetermined coefficient (k) to the capacitance of the second conductor (C ₂₎ Calculating a difference signal (CD) obtained by taking an absolute value of
When the sum signal (CA) is larger than the predetermined sum signal threshold value (CA _th ) and the difference signal (CD) is smaller than the predetermined difference signal threshold value (CD _th ), that is, when the following equation is satisfied, the right hand and the left hand are detection method characterized by both a step of detecting the approaching the first and second conductors.

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