JPH092589A - Liquid dispenser - Google Patents

Abstract

PURPOSE: To detect the residual quantity of a liquid in a container in a stabilized manner by providing in an apparatus, by which the liquid is dispensed from a pouring hole communicating through a tube with the container, a capacitance type sensor for detecting the liquid flowing through the tube to detect the residual quantity in the container based on the output of the capacitance type sensor. CONSTITUTION: In a food/beverage dispenser 1 which serves in a paper cup a juice prepared by diluting its concentrated liquid with water a command for a serving is executed by rotation of a roller pump 10 actuated by a drive motor and downward discharge of the undiluted liquid contained in a closed space in a tube 7. In this instance, in the upper part of the food/beverage pouring part 4 a capacitance type sensor 20 detects the electrostatic capacity of the undiluted liquid that flows through the tube 7. When the undiluted liquid in its container 6 decreases and as the liquid level goes down through the tube 7 where the sensor 20 is provided, the capacitance across the electrode violently decreases. Therefore, it is possible to detect whether there is liquid in the tube 7 or not and the quantity of the liquid inside the container 6 as well.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid supply device for discharging a liquid such as food and drink filled in a container, and more particularly to a liquid supply device for detecting and displaying the remaining amount in a mounted container. It is a thing.

[0002]

2. Description of the Related Art In recent years, a food and drink supply device used for providing palatable drinking water or the like has a container filled with liquid food and drink in addition to a can juice type device. However, there are many things that are poured out from the container into paper cups or the like and provided according to demand. Especially for the latter, it can be provided in a simple and unnecessary paper cup, such as coffee, juice, and shakes provided at fast food stores, which can be used at low cost. It is flourishing. By the way, the food and drink supply device of the type for pouring out the one filled in such a container is different from the one which is pre-packed and sold in a can,
It is necessary that a certain amount of pouring is performed each time.
This type of food and drink supply device supplies a certain amount of the undiluted solution of food and drink to a cup and supplements water etc. to complete juice and other food and drink, but when the amount of undiluted solution changes, juice according to the manual is provided Because you can't.

Therefore, what must be noted in the pouring type food and drink supply device is to constantly pour out a fixed amount of the stock solution. In particular, when the stock solution in the container is running low, the last one may not reach a predetermined amount, and there is a risk that proper food and drink cannot be provided. This can occur not only when it is provided by a vending machine, but also when it is used at a fast food restaurant or the like. This is because even if the operator is careful, a slight difference cannot be recognized. And, providing such an inappropriate thing changes the taste, and this is a matter that is particularly cautioned because it damages the credibility of the store. On the other hand, it is also attempted to reduce the time loss due to container replacement as much as possible by displaying an indication when the remaining amount in the container is below a certain amount and urging the operator to prepare to replace the container. There is.

Therefore, in the food and drink supply device, when the remaining amount of food and drink in the container becomes a certain amount or less, a sale stop warning display or a container replacement caution display is issued. Specifically, a weight detection method or a light detection method is adopted to detect the remaining amount in the container. That is, in the weight detection device, a weight sensor is attached so that the weight of the entire container is constantly detected, and when the weight falls below a certain amount, the detection signal is sent to a predetermined display device to stop sales or replace. Lights up. On the other hand, in the light detection method, a transmissive optical sensor was provided in the middle of the pipe from the container to the pouring part to detect the presence or absence of food or drink flowing through the pipe, and to detect the amount of light when there was no food or drink. At times, the detection signal is sent to a predetermined display device to turn on the sale stop warning display.

[0005]

However, in the liquid supply device provided with the detection device for detecting the remaining amount of the liquid such as food and drink, the following inconveniences occur. That is,
For example, when the installation position of the container installed in the food and drink supply device deviates from a predetermined reference position, the remaining amount sensed by the weight sensor is different each time, and there is a problem that the remaining amount cannot be accurately detected. Also, the container containing food and drink is usually
Vinyl and plastic containers in which food and drink are directly placed are further placed in cardboard for transportation, and when they are attached to the liquid supply device, they are inserted as they are in cardboard. In this case, during the rainy season, the corrugated cardboard contains water and becomes excessively heavy, and in the winter, the corrugated cardboard becomes lighter than normal and the weight becomes lighter than usual. It was difficult to detect.

Further, since the weight measurement value of the container changes due to the influence of the change in the stress generated by the decrease in the liquid in the container at the joint between the container and the supply device, the residual amount detection is likely to vary. Further, since the contact switch is used, if the frequency of use increases, the remaining capacity detection capability deteriorates, and the detection accuracy decreases, which may cause variations. As the detection results are not stable as described above, the food and drink in the container is below the prescribed amount of undiluted solution poured at one time, and even if there is no undiluted solution in the container, indication such as sales stop is displayed. There were times when it wasn't.

Further, as described above, in the weight detecting device,
In addition to variations in the detection results, since the accuracy is basically low, it is necessary to notify the replacement time with a certain amount of remaining food and drink in the container. At this time, the food and drink remaining in the container to be disposed of is also wasted because it is similarly disposed of, and becomes a target of disposal. This is a waste of resources and has been a cause of increased costs. On the other hand, when a transmissive optical sensor is used, it is necessary to allow light to pass through at the detection point in principle, and there is a problem that detection cannot be performed depending on the material of the container or tube. That is, in the food and drink supply device, since the food and drink to be provided do not normally receive light, it is often contained in a non-transparent container such as black and is often conveyed by a non-transparent tube such as a black tube. Is.

Therefore, an object of the liquid supply apparatus of the present invention is to provide a liquid supply apparatus capable of stably detecting the remaining amount of the liquid in the container.

[0009]

The liquid supply apparatus of the present invention is capable of replacing a container filled with liquid, and is capable of removing the liquid in the container from a spout connected through a tube connected to the container. It is a liquid supply device that pours out, a capacitance type sensor that is attached closely to the tube and detects the liquid flowing in the tube, and the amount of liquid in the container is a predetermined amount based on the output value of the capacitance type sensor. It has a remaining amount detecting means for determining the following. Further, in the liquid supply device of the present invention, in the above device, the remaining amount detecting means has a first threshold value for detecting that the liquid is not in the tube, and the liquid remaining in the container. And a second threshold value for detecting that is less than or equal to a predetermined value. Further, the liquid supply device of the present invention is, in the above device, a first display means for displaying that the first threshold value or more, and less than the second threshold value and the first threshold value or more. It is characterized in that it has a second display means for displaying the above, and a third display means for displaying below the first threshold value.

[0010]

The liquid supply apparatus of the present invention pours the liquid in the container into a paper cup or the like via a tube. Here, the capacitance type sensor detects the capacitance of the liquid in the tube. A feature of the capacitance type sensor is that even if the tube is non-transparent, the presence or absence of liquid in the tube can be detected. On the other hand, it has been confirmed that the capacitance of the liquid in the tube changes depending on the amount of the liquid in the container that is continuous with the liquid in the tube. Therefore, by measuring the capacitance of the liquid present in the tube, it is possible to detect not only the presence of the liquid in the tube, but also the amount of the liquid remaining in the container. is there. The first threshold value stored by the remaining amount detecting means of the present invention is for detecting that there is no liquid in the tube. Also,
The second threshold value is for detecting that the amount of liquid remaining in the container has dropped below a certain amount.

Therefore, when the output of the capacitance type sensor is equal to or higher than the first threshold value, it is indicated by the first display means that the liquid in the container is present and pouring is possible. When the output of the capacitance type sensor becomes less than the second threshold value, the second display means displays that the liquid in the container has become less than or equal to a predetermined amount. When the second display means is displayed, the worker can still pour out the liquid and supply the liquid, but since the liquid will soon run out, the worker will carry out work such as transporting the next container from the refrigerator. Next, when the output of the capacitance type sensor becomes equal to or lower than the first threshold value, the third display means indicates that the liquid in the tube is exhausted. When the third display means is displayed, it is unclear whether or not the amount of liquid currently being dispensed is appropriate.Therefore, the operator should discard the liquid that is being poured into the paper cup and immediately prepare it. Replace with a new container and pour liquid from the new container.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a food and drink supply device which is a liquid supply device according to the present invention will be described with reference to the drawings. FIG. 3 is a front view showing the overall configuration of the food and drink supply device 1 with the front door 2 opened. In this example, the concentrated stock solution is diluted with water to produce orange juice. The food and drink supply device 1 is roughly divided into a container storage part 3 arranged at the upper part, and food and drink in a container 6 stored in the container storage part 3 (in this embodiment, a concentrated concentrate of orange juice, Hereinafter, it is composed of a food and drink pouring part 4 for pouring out a predetermined amount of "undiluted solution", and a water supply part 5 for receiving the undiluted solution. In the present embodiment, the food and drink supply device 1 shown includes a container 6 and a food and drink outlet 4.
Although it has a set, of course, it may have two sets, or may have three or more sets. The container storage unit 3 has a partitioned internal space for storing the container 6, and has a bottom surface formed with an insertion hole (not shown) for inserting a tube. Here, the container 6 accommodated in the container accommodating portion 3 has various forms such as a plastic container, a vinyl container or a paper container, and any of them is filled in the container downward. A tube 7 is continuously provided for pouring the stock solution.

Next, the food and drink dispenser 4 will be described in detail. FIG. 4 is an enlarged front view of the food / drinks pouring part 4. The food-drinking part 4 is provided on a substrate 8 to which a tube 7 from a container 6 is attached. In particular,
A roller pump 10 having three rollers 9 provided on the outer periphery thereof at equal intervals via a torsion spring 11 is formed in the upper center part. The roller pump 10 is rotatably held around a roller pump shaft 13 and is driven by a drive motor (not shown). In addition, a tube guide 12 provided alongside the roller pump 10
Is curved along the outer periphery of the roller pump 10. The tube guide 12 is attached so as to be rotatable around the tube guide shaft 19. However, the tube guide stopper 14 is provided so that the tube guide 12 does not rotate too much and approaches the roller pump 8 too much. In this way, the tube guide 12 is screwed to the illustrated position by the tube guide lock 15.

A pinch guide 16 is provided at a position downstream of the tube guide 12 and the roller pump 10, and a pinch valve (not shown) for crushing and closing the tube 7 in the vicinity of the spout of the tube 7 for sealing and opening. Is provided. In the food / drink extraction part 4 formed in this way, the conduit in which the tube 7 is arranged is determined as shown in the figure.
The dilution water supply nozzles 17 provided on both sides of the tube 7 in the vicinity of the spout are rotatably fitted in the nozzle receiver 17a attached to the substrate 8, and the dilution water is discharged by the rotation operation. It is designed so that it can change direction. The dilution water supply nozzle 17 is connected to a water distribution pipe (connected to a water supply or the like) in the device that supplies the dilution water. Further, in the water supply unit 5, as shown in FIG. 3, below the tube 7 and the dilution water supply nozzle 17, a bracket 18 that supports the pouring of the stock solution in the container 6 is provided. The bracket 18 is a plate-like member that is fixed at the upper portion and is provided so that the lower tip portion inclines toward you.

By the way, as shown in FIG. 4, a capacitance type sensor 20, which is a feature of the food and drink supply apparatus 1 of the present embodiment, is provided on the food and drink outlet 4, and a power switch 32, Control knob 3 for adjusting the discharge rate of syrup
3 and a changeover switch 35 for switching the sold-out warning display. The capacitive sensor 20 is fixed on the food / drink extraction part 4 such that its detection surface 21 a faces the tube 7 connected to the container 6.

FIG. 5 is a view showing a cross section of the capacitance type sensor 20. This capacitance type sensor 20 is used in the case 2
The convex portion 1 serves as the detection surface 21a, and the electrode 22 is fitted inside thereof. The connecting wire 23 is connected to the electrode 22.
The printed circuit board 24 is connected via. The printed circuit board 24 is provided with a sensitivity detection potentiometer 27 that adjusts the detection sensitivity by changing the contact position. This sensitivity detection potentiometer 27 is
It is possible to adjust the value of the capacitance produced by the target food and drink.

Next, the control device of the food and drink supply device 1 will be described. As shown in FIG. 2, the printed circuit board 24 connected to the electrode 22 is connected to the processing unit 28. The processing unit 28 is connected to the dispenser control unit 29 and the display unit 30. The display unit 30 includes a green LED 30a serving as a first display means and a yellow LED 3 serving as a second display means.
0b and a red LED 30c which is the third display means are provided. Processing unit 28, dispenser control unit 2
9 and the display unit 30 constitute a remaining amount detection unit 31.

On the other hand, the case 2 in which the detection surface 21a is formed
An outlet 26 for the cable 25 is formed at the other end of the cable 1. The cable 25 pulled out from the outlet 26 is connected to a remaining amount detecting section 31 which is a remaining amount detecting means. Here, the capacitance type sensor 20 is filled with resin (not shown) inside the case 21 in order to ensure vibration resistance, shock resistance, and water resistance. In addition, the printed circuit board 24,
A circuit as shown in FIG. 6 is connected and configured. That is, the oscillation circuit 41 is connected to the electrode 22,
This constitutes a part of the electrode, and the oscillation circuit 41 is connected with a detection circuit 42 for detecting an oscillation signal from the oscillation circuit 41, and further, a voltage switch circuit 43 and an output circuit 44 are sequentially connected.

Next, the food and drink supply device 1 having the above-mentioned structure
The operation of will be described. First, before driving the food / drink supply device 1, the container 6 containing the stock solution is mounted in the container storage portion 3. Then, the tube 7 connected to the container 6 is attached to a predetermined path of the food / drink extraction part 4. Specifically, the tube guide 12 is opened, and the tube 7 is applied to an insertion hole portion (not shown) formed when the tube guide 12 contacts the tube guide stopper 14. And
The tube 7 is attached along the circumference of the roller pump 10, and the tip is hung downward so as to abut against a pinch valve (not shown) on the back of the pinch guide 16. After the arrangement of the tubes 7 is determined in this way, the tube guide 12 is rotated counterclockwise so as to cover the tubes 7. Then, the tube 7 is pressed against the roller 9 by the tube guide 12. However, at this time, rotation of the tube guide 12 is restricted by the tube guide stopper 14, and an excessive load on the tube 7 is prevented. Then, the tube guide lock 15 fixes the position.

Next, after the installation of the container 6 and the tube 7 is completed as described above, the power switch 32 is turned on to activate the food and drink supply device 1. And the adjustment knob 3
The capacitance corresponding to the stock solution in the container 6 mounted by 3, 34 is adjusted. This completes the preparation for providing food and drink. Then, hold the cup 36 and the bracket 18
When it is pressed against, a pouring command is issued, and the food / drink pouring part 4 is driven as described below, and the orange juice is poured into the cup 36.
Created and provided within. A spring 11 acts on each roller 9 in the radial direction of the roller pump 8. Therefore, when the tube 7 is arranged in the food / drink extraction part 4,
A closed portion 7a of the tube 7 which is compressed by the roller 9 and the tube guide 12 is formed between the two rollers 9.
In FIG. 2, two closed parts 7a are formed.

When a beverage supply command is issued, the roller pump 10 is rotated by a drive motor (not shown) in the direction of arrow A in FIG. When the roller pump 10 rotates 120 ° in the direction of arrow A, only the amount of the stock solution filled between the two closed parts 7a is sent downward so as to be squeezed out. At this time, the undiluted solution from the container 6 flows between the closed portions 7a to which the undiluted solution has been sent out, and is closed again by the next roller 9. Therefore, the amount of the undiluted solution poured out by one rotation is the amount existing between the closed portions 7a. A pinch guide 16 is provided at a position downstream of a position between the tube guide 12 of the tube 7 and the roller pump 10, and a pinch valve (not shown) and its driving mechanism are provided on the back side of the pinch guide 16. There is. In order to keep the tube 7 clean, when there is no drink supply command, the pinch valve presses the tube 7 against the back surface of the pinch guide 16 to seal it and prevent the drink in the tube 7 from contacting the outside air. The roller pump 10 is opened at the same time as the rotation.

When the stock solution is poured out from the spout at the lower end of the tube 7 as described above, at the same time, the dilution water for diluting the stock solution is poured out from the dilution water supply nozzle 17. The dilution water supply nozzle 17 is rotatably fitted in a nozzle receiver 17a attached to the substrate 8, and the rotation direction thereof can change the discharge direction of the dilution water. Here, the diluting water may be supplied from a water supply such as a water supply, or mineral water or the like may be stored in the food and drink supply device 1 and supplied.

In this way, the appropriate amount of the stock solution in the container 6 is poured out, and the appropriate orange juice is provided by the dilution water from the dilution water supply nozzle 17. Next, the remaining amount detection, which is the main part of the present invention, will be described. That is, the capacitance of the undiluted solution flowing in the tube 7 at the upper position of the food / drink extraction part 4 is detected by the capacitance type sensor 20. FIG. 7 is a conceptual diagram showing a detection situation by the capacitance type sensor 20. The capacitance type sensor 20 is shown in FIG.
As shown in (a), an object, that is, an undiluted solution in the tube 7 is subjected to electrostatic induction in the electric field, so that polarization is performed. That is, a negative charge, which is different from the positively charged electrode 22, appears on the side of the stock solution near the electrode 22, and a positive charge appears on the opposite side. Then, the positive charge on the electrode 22 side increases due to the induction of the negative charge generated in the stock solution. Therefore, the increase of the electric charges increases the capacitance of the electrode 22.

On the other hand, as shown in FIG. 7B, when the stock solution in the container 6 is reduced and the final surface passes through the position of the tube 7 in which the capacitance type sensor 20 is installed, the capacitance of the electrode 22 is reduced. It will fall sharply. FIG. 1 shows the relationship between the output value of the capacitance type sensor 20 used in this embodiment and the amount of the stock solution remaining in the container 6. In the upper graph, the horizontal axis shows the amount of the stock solution in the container 6, and the vertical axis shows the output of the capacitance type sensor 20. C when the remaining amount is zero,
The time when the remaining amount is a predetermined amount is indicated by b, and the time when the container 6 is full is indicated by a. In this embodiment, the predetermined amount is the amount for the remaining 5 cups. Here, the first threshold value c stored in the processing unit 28 is for detecting that there is no liquid in the tube. Further, the second threshold value b is for detecting that the liquid remaining in the container has become equal to or less than a certain amount.

The amount of the undiluted solution remaining in the container 6 can be detected as shown in FIG. 1 because the capacitance of the liquid in the tube is continuous with the liquid in the tube as shown in FIG. Because it changes. Therefore, by measuring the capacitance of the liquid present in the tube, it is possible to detect not only the presence of the liquid in the tube, but also the amount of the liquid remaining in the container. is there.

The change in the electrostatic capacitance of the electrode 22 is oscillated by the oscillation circuit 41 configured such that the electrostatic capacitance becomes a factor of the oscillation condition. Then, the oscillation oscillated from the oscillation circuit 41 in proportion to the electrostatic capacity is adjusted as a voltage signal by the detection circuit 42 and the voltage switch circuit 43, and the processing unit 2
Send to 8. By confirming the presence or absence of voltage, the processing unit 28 collates with the corresponding data of FIG. 1 to detect the remaining amount,
When the remaining amount is equal to or less than a and equal to or greater than the first threshold value c, the green LED 30a for indicating that the liquid can be supplied is turned on. Then, when the first threshold value c is detected, that is, when it is detected that there is no stock solution in the tube 7,
The green LED 30a is turned off, and the red LED 30c for stopping the liquid supply is turned on. When the capacitance type sensor 20 detects the predetermined amount b, the yellow LED 30b is turned on to indicate that the replacement time is near. That is,
When the output of the capacitance type sensor is equal to or higher than the first threshold value c, the presence of the liquid in the container is indicated by the green LED 30a. The output of the capacitance sensor is the second threshold b
When it is less than the predetermined value, the yellow LED 30b indicates that the liquid in the container has become less than or equal to a predetermined amount. When the yellow LED 30b is displayed, the operator can still pour out the liquid and supply the liquid, but soon the liquid runs out,
Carry out the next container from the refrigerator. next,
When the output of the capacitance type sensor becomes the first threshold value c or less, the red LED 30 indicates that the liquid in the tube is exhausted.
Display by c. When the red LED 30c is displayed,
Since it is unclear whether the amount of liquid currently being poured out is appropriate, the operator discards the liquid being poured into the paper cup,
Immediately replace with a new container prepared and pour out the liquid from the new container.

By the way, the relative permittivity indicates the degree to which the electric charge in an object is polarized by electrostatic induction. When the relative dielectric constant is set to 1 on the basis of the case of vacuum, liquid such as about 80 water is relatively large. On the other hand, many solids are 10 or less. From this, it can be said that a substance containing a large amount of water, such as the food and drink supplying device of this embodiment, is easy to detect. Therefore, the capacitance is determined by the relative dielectric constant of the object flowing in the tube 7. Further, the sensitivity detecting potentiometer 27 adjusts the sensitivity increase by the tube 7 which is not originally required to be detected to be an appropriate sensitivity.

As described above, according to the food and drink supplying apparatus 1 of this embodiment, the capacitance type sensor 20 which is attached to the tube 7 so as to detect the liquid flowing in the tube 7 and the capacitance A processing unit 28 that determines from the output value of the mold sensor 20 that the amount of liquid in the container 6 is less than or equal to a predetermined amount.
Since it has, and the non-transparent tube can be used, the remaining amount can be accurately detected, and the presence of a predetermined amount in the container 6 can be detected. Therefore, the replacement time of the container 6 can be shortened.

Further, according to the food and drink supply device 1 of this embodiment, the processing unit 28 remains in the tube 7 and the first threshold value c for detecting that the liquid is not in the tube 7. A second threshold value b for detecting that the liquid amount is less than or equal to a predetermined amount is stored, and a green LED 30a indicating that the liquid amount is equal to or greater than the first threshold value c and a second LED value less than the second threshold value b Yellow LED 30b indicating that the threshold value is not less than c
And a red LED 3 indicating that it is below the first threshold
Since it has 0c, it can display to the operator that a predetermined amount is present in the container 6, so that the operator can be prepared in advance, and the replacement time of the container 6 can be shortened. be able to.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention. For example, in this embodiment, the display means L
Although the ED is used, other optical means such as a lamp may be used. Further, in the present embodiment, three display means are used, but the two display means may be used to display the lights in different cases. Further, in the present embodiment, the first display means is displayed above the first threshold value, but the first display means may be displayed above the second threshold value. Further, in the present embodiment, a cylindrical electrostatic capacity type proximity switch is adopted as the remaining amount detector, but it may be a flat type. Further, for example, the mounting position of the remaining amount detector is not limited to the position of the above embodiment,
It only needs to be in a position where at least one dispensing amount is left.

[0031]

As described above, according to the liquid supply apparatus of the present invention, the capacitance type sensor that is attached to the tube and detects the liquid flowing in the tube, and the output of the capacitance type sensor. Since it has a residual amount detecting means for judging that the amount of liquid in the container is less than a predetermined amount from the value, the residual amount can be accurately detected even if a non-transparent tube is used. Since it is possible to detect the presence of a predetermined amount in the container, it is possible to notify the operator of the caution in advance, and it is possible to shorten the replacement time of the container.

[Brief description of drawings]

FIG. 1 is a diagram showing output data of a capacitance type sensor 20 used in a food and drink supply device 1 according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a control means of the food and drink supply device 1.

FIG. 3 is a front view of the food and drink supply device 1.

FIG. 4 is an enlarged view showing a configuration near a mounting position of the capacitance type sensor 20.

FIG. 5 is a cross-sectional view showing the configuration of the capacitance type sensor 20.

6 is a block diagram showing a circuit configured on a printed circuit board of the capacitance type sensor 20. FIG.

FIG. 7 is an explanatory diagram illustrating an operation of the capacitance type sensor 20.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Food / drink supply device 4 Food / drink extraction part 6 Container 7 Tube 9 Roller 10 Roller pump 11 Spring 12 Tube guide 20 Capacitance type sensor 22 Electrode 24 Printed board 30 Display part 30a Green LED 30b Yellow LED 30c Red LED 33 Adjustment Knob

Claims (3)

[Claims] 1. A liquid supply device capable of replacing a container filled with a liquid and pouring the liquid in the container from a spout connected to the container via a tube connected to the container. And a capacitance type sensor attached to detect the liquid flowing in the tube, and a residual amount detecting means for determining from the output value of the capacitance type sensor that the amount of the liquid in the container is a predetermined amount or less. And a food and drink supplying device. 2. The liquid supply apparatus according to claim 1, wherein the remaining amount detection means remains in the container and a first threshold value for detecting that the liquid is not in the tube. A liquid supply device, which stores a second threshold value for detecting that the liquid is below a predetermined value. 3. The liquid supply apparatus according to claim 2, wherein the first display means indicates that the value is equal to or more than the first threshold value, and the value is less than the second threshold value and equal to or more than the first threshold value. A liquid supply device comprising: a second display means for displaying that the above is present; and a third display means for displaying that the above is less than the first threshold value.