JPH0639162B2 - Ink volume abnormality alarm output method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for outputting an abnormality in an ink liquid amount alarm, and more particularly, an ink jet recording apparatus that detects the amount of ink stored in an ink tank and issues an alarm based on the detection result. And a method for outputting an ink liquid amount abnormality alarm in.

2. Description of the Related Art In an ink jet recording apparatus that performs dot recording by ejecting ink as droplets, a sub-ink tank that is directly connected to a nozzle that ejects an ink droplet and is disposed in the vicinity of the nozzle, and an ink that is supplied to this sub-ink tank. A configuration in which a main tank for storing the above is separately provided is widely used.

In this case, the sub-ink tank is usually sealed, and an air layer is secured inside the sub-ink tank in order to absorb the pressure fluctuation of the ink inside due to the movement of the tank during the recording operation.
Then, as the ink droplets are ejected from the nozzles by the recording operation, the same amount of ink as the ejection amount is sequentially supplied from the main ink tank to the sub ink tank.

According to this configuration, when the ink in the main ink tank becomes empty, the ink in the sub ink tank naturally decreases along with the recording operation and the ink runs out. Even when ink is present, the amount of ink stored in the sub ink tank may decrease, and ink may run out.

For example, if the recording device is left for a long period of time or the outside temperature fluctuates drastically, the air dissolved in the ink in the sub ink tank may come out of the ink, or the sub ink tank and its ink supply Air intrudes into the sub ink tank through the connecting portion with the tube to increase the air layer, thereby reducing the amount of ink in the sub ink tank.

In this case, it is necessary to remove air from the sub ink tank and forcibly supply ink from the main ink tank to the sub ink tank.

Therefore, it is necessary to distinguish between the ink shortage due to the decrease in the ink amount in the main ink tank and the ink shortage due to the decrease in the ink amount only in the sub ink tank.

For this purpose, an ink amount detection alarm device for detecting both the ink in both tanks and issuing an alarm based on the detection result is used. According to the conventional configuration, the liquid amount detection for each tank and the alarm based on the result are detected. In order to carry out separately, the liquid amount detecting means is provided for each tank, and the alarm means is also provided separately for each tank, whereby the detection and the alarm are performed separately for each tank.

However, in such a configuration, since a plurality of detecting means and a plurality of warning means are provided, the cost of the entire ink jet recording apparatus becomes high and the occupying space of the warning means and the like becomes large.

The above drawbacks are not limited to the ink amount detection of the ink jet recording device and the alarm device described above, and in devices using other liquids, one of the plurality of tanks connected to supply the stored liquid to the other can detect the liquid amount and This applies to all of the liquid amount detection and alarm devices that perform an alarm based on the detection result separately for each tank.

The present invention has been made in view of the above circumstances, and in the liquid amount detection / alarm device of the type described above, a single detection unit and an alarm unit detect the amount of liquid in each tank and issue an alarm based on the detection result. It is an object of the present invention to provide an ink liquid amount abnormality alarm output method that can be distinguished and that can reduce the cost and downsize the entire apparatus in which it is provided.

Examples The present invention will be described in detail below based on the examples shown in the drawings. In this case, an ink amount detection alarm device used in the ink jet recording device is used as an example.

FIG. 1 shows the essential structure of an ink jet recording apparatus to which the apparatus of the present invention is applied.

In the figure, reference numeral 1 denotes a nozzle for ejecting ink droplets for recording, which is provided on a carriage 2 slidably provided on a guide shaft 3. Further, a sub-ink tank 4 in which the ink I is stored is provided behind the nozzle on the carriage 2. The sub-ink tank 4 is made of a rigid material and has a closed structure.
A rear portion of a supply pipe 5 for supplying ink, the front end of which is connected to the rear end of the nozzle 1, is arranged therein.

The rear end of the supply pipe 5 is bent toward the bottom surface of the sub ink tank 4, is immersed in the ink I in the sub ink tank 4, and a filter 6 is fitted to the tip thereof.
The filter 6 prevents foreign matters such as dust and bubbles from entering the nozzle 1 in the ink I, and the inside of the sub-ink tank 4 caused by the inertia of the movement of the supply tube 10 described later during the recording operation. It also plays the role of absorbing the pressure rise of the ink I.

Further, the rear end portion of the atmosphere communication pipe 7 faces the upper portion inside the sub ink tank 4. The diameter of this atmosphere communication pipe 7 is
It is formed as a straight glass capillary having a diameter of 100 μm to 400 μm, and its tip faces above the tip of the nozzle 1.
An air layer 8 of a predetermined amount or more is secured in the upper part of the sub ink tank 4 via the atmosphere communication pipe 7. When the liquid level of the ink I in the sub ink tank 4 tries to rise above the atmosphere communication pipe 7, the air layer 8 inside the sub ink tank 4 is completely sealed by the ink entering the atmosphere communication pipe 7. The air layer 8 does not decrease as described above. This air layer 8
Like the above-described filter 6, plays a role of absorbing the ink pressure in the sub ink tank 4 during the recording operation.

Further, on the inner wall surface of the sub ink tank 4, there is provided an electrode pair 9 which is an ink amount detection means of the ink amount detection alarm device according to the present invention, and this electrode pair 9 is connected to an ink amount detection alarm device described later. Has been done. The height of the arrangement of the electrode body 9 is the height of the ink liquid level in the sub ink tank 4 at the time of alarm, but if it is too high, the alarm becomes frequent and if it is too low, the ink liquid level at the time of operation. When the pressure drops to that extent, the filter 6 is exposed from the ink I due to the vibration of the ink in the tank, and air enters the nozzle 1 from there, so these are selected appropriately.

A supply tube 10 for supplying ink is connected to the sub ink tank 4 described above.
A hollow burr 11 is connected to the tip of 0, and the hollow burr 1
1 is inserted in a rubber plug 14 of a main ink tank 12 connected to a bag-shaped ink container 13 provided in the main ink tank 12.

On the other hand, the reference numeral 15 in the drawing is a pump for forcibly supplying the ink I from the main ink tank 12 to the sub ink tank 4 when an alarm of the decrease in the amount of ink in the sub ink tank 4 is issued. A suction cap 16 is connected to the pump 15. Further, this pump is operated by an operation switch 15a not shown in FIG. 1, but this operation switch 15a is connected to an ink liquid amount detection alarm device described later.

With the above configuration, at the time of recording, the carriage 2 is caused to travel on the guide shaft 3 by a driving unit (not shown), and the nozzle 1 is driven to print ink on a recording paper (not shown) that is arranged to face the nozzle 1. Dot recording is performed by ejecting drops. In this case, the ink I in the sub ink tank 4 is consumed.
The ink is sequentially supplied to the sub ink tank 4 via the hollow needle 11 and the supply tube 10.

Here, when the apparatus as described above is left for a long period of time, or when the outside air temperature fluctuates significantly, the air layer 8 in the sub ink tank 4 increases and the liquid level of the ink I in the sub ink tank 4 becomes low. . When the liquid level of the ink becomes lower than that of the electrode pair 9, it is detected by an ink amount detection alarm device, which will be described later, and an alarm is issued.

In response to this alarm, the ink is forcibly supplied to the sub ink tank 4. In that case, in FIG. 1, the suction cap 16 is driven by a driving means (not shown) and fitted into the tip portion of the nozzle 1 and the atmosphere communication pipe 7. Then, the actuating switch 15a is turned on automatically or manually to operate the pump 15 and perform suction.

Due to the negative pressure of this suction, the air in the air layer 8 in the sub ink tank 4 is sucked out through the atmosphere communication pipe 7, and the corresponding amount of ink I is transferred from the ink container 13 of the main ink tank 12 to the rubber plug 14 and the hollow needle. 11, supplied via the supply tube 10. At the same time, the ink I is also sucked from the nozzle 1 and the ink is secured in the nozzle 1. However, this suction raises the ink surface in the sub-ink tank 4, and when the height of the ink reaches the atmosphere communication pipe 7 after the height exceeds the electrode pair 9, the suction operation is terminated and the required amount of air layer 8 is formed. It is configured to be secured in the tank.

Of course, when the amount of ink in the main ink tank 12 is exhausted or small during this suction operation, ink is not supplied or the amount of supply is reduced.

Next, the configuration of the liquid amount detection alarm device according to the present invention provided in the above configuration will be described. Here, this device is called an ink amount detection alarm device.

FIG. 2 shows the circuit configuration of the ink amount detection alarm device. In the figure, the resistance indicated by the reference symbol Rx is the resistance between the electrode pair 9 described above, one end of which is connected to the power supply V + via the resistance R1 and the other end of which is connected to the collector of the transistor T1 whose emitter side is grounded. Has been done. This resistance R
1, Rx, and a resistor R2, R3 are connected in parallel to the transistor T1 to form a bridge circuit. A connection point a between the resistors R1 and Rx of the bridge circuit is formed.
By detecting the potential difference at the connection point b between the resistor R2 and the resistor R3 with the comparator 17, it is detected whether the height of the ink surface in the sub ink tank 4 is above the electrode pair 9.

The output of the comparator 17 is supplied to the set input of a flip-flop 21 via an AND gate 18, and to the flip-flop 21 via an inverter 19 and a NAND gate 20.
Connected to the reset input of. AND gate 18,
A pulse of the detection timing signal P1 that is led to the base of the transistor T1 via the current limiting resistor R4 during detection is simultaneously guided to the other input of the NAND gate 20.

The flip-flop 21 is composed of, for example, a D flip-flop or a JK flip-flop, and is configured so that the output changes when the input changes from the low level to the high level, and the flip-flop 21 is caused by the output.
The AND gate 22 to which one input is connected is opened and closed.

The output of the AND gate 22 is connected to the base of the transistor T2 via the current limiting resistor R5, and the output of the AND gate 22 turns on / off the transistor T2. Further, the collector side of the transistor T2 is connected to the alarm display LED23 connected to the power supply V +, the emitter side is grounded, and the current is applied to or cut off from the LED23 by turning on / off the transistor T2. It is turned on and off.

On the other hand, an oscillator 27 that outputs a pulse of the intermittent signal P2 is connected to the other input of the AND gate 22 via a NAND gate 26. The output of the flip-flop 24 is connected to the other input of the NAND gate 26 via an inverter 25.

The flip-flop 24 is composed of a D or JK flip-flop like the flip-flop 21 described above, and its output changes when the input level changes from low to high. The set input is connected to the power supply via the inverter 28 and the resistor 7, the input of the inverter 28 is grounded via the operation switch 15a, and the voltage level applied to the set input of the flip-flop 24 by turning on / off the operation switch 15a. Can be changed. The reset input of the flip-flop 24 is the flip-flop 2 described above.
The output of NAND gate 20, which is connected to the reset input of 1, is connected.

Next, the operation of the ink amount detection alarm device having the above configuration will be described.

At the time of non-detection, the pulse of the detection timing signal P1 is not guided to the transistor T1 and the transistor T1 is off. Therefore, the potential of the connection point a of the bridge circuit is higher than the potential of the connection point b, and the output of the comparator 17 is output. Is at a high level.

Since the detection timing signal P1 is not guided to the AND gate 18, the set input from the AND gate 18 is low level and the flip-flop 21 is not set. Further, the high level output of the comparator 17 is inverted to the low level by the inverter 19 and the NAND gate 2
Since the other input of the NAND gate 20 is at the low level, the output of the NAND gate 20 is at the high level. For this reason the flip-flop 21
Has been reset, and the AND gate 22 is closed by the low level output.

On the other hand, at this time, the operation of forcibly supplying ink to the sub ink tank 4 is not performed, so the operation switch 15a is turned off, and the power supply voltage is inverted to a low level by the inverter 28 at the set input of the flip-flop 24. Is being applied. Further, since the high level output is led from the NAND gate 20 to the reset input, the flip-flop 24 is reset, and the low level output is inverted to the high level by the inverter 25 and is led to the input of the NAND gate 26. .

Therefore, the intermittent signal P2 guided from the oscillator 27 to the NAND gate 26 is inverted by the NAND gate 26 and guided to the AND gate 22. However, at this point, the AND gate 22 is closed as described above.

Since the output of the AND gate 22 is low level, the transistor T2 is cut off and the LED 23 is not turned on.
No alarm is given.

In order to avoid erroneous detection, the ink amount is detected when the carriage 2 is stopped, and the detection timing signal P1 is led from the control circuit (not shown) to the circuit of the ink amount detection alarm device.

Here, when a sufficient amount of ink I is present in the sub ink tank 4 and the liquid surface thereof is at a position higher than the electrode pair 9, the resistance Rx between the electrode pair 9 is several hundreds KΩ.
It is several MΩ.

The application of the detection timing signal P1 turns on the transistor T1 only during the pulse width, the power supply voltage is applied to the electrode pair 9 in response to the pulse, and the potential difference between the connection points a and b of the bridge circuit is detected by the converter 17. To be done. Here, the voltage is not continuously applied to the electrode pair 9 because
This is to prevent electrolysis of the ink in the tank.

At this time, the resistance Rx is in the range of several hundred KΩ to several MΩ, so that the potential of the connection point a becomes lower than the potential of the connection point b, and the output of the comparator 17 changes from the high level to the low level.

Therefore, the output of the AND gate 18 is the detection timing signal P.
1 remains at low level even if it is led to the input. On the other hand, the low level output of the comparator 17 is the inverter 19
Since it is inverted to a high level and guided to the NAND gate 20, the output of the NAND gate 20 changes to a low level and then returns to a high level by the input of the detection timing signal P1.

Therefore, the flip-flop 21 is kept in the reset state at the time of no detection, and the output is kept at the low level, so that the AND gate 22 is not opened. That is, due to the low level output of the AND gate 22, the transistor T2 is cut off, the LED 23 is not turned on, and the alarm is not issued.

Next, when the ink amount in the sub ink tank 4 decreases and the position of the ink surface becomes lower than the electrode pair 9, the resistance Rx becomes infinite due to the absence of ink between the electrodes 9. As a result, the potential at the connection point a becomes higher than the potential at the connection point b, and the output of the comparator 17 changes from the low level to the high level. The flip-flop 21 is set by the high level output of the AND gate 18 which is the sum of this and the detection timing signal P1, and the AND gate 22 is opened by the high level output.

When the AND gate 22 is opened, the inverted continuation signal P2 from the NAND gate 26 side is guided to the base of the transistor T2, and the transistor T2 is continuously turned on / off. As a result, a current is intermittently applied to the LED 23, the LED 23 blinks intermittently, and a warning that the amount of ink in the sub ink tank 4 is low is issued.

Next, in response to this alarm, the pump operating switch 15 is operated to forcefully supply ink to the sub ink tank 4.
When a is turned on automatically or manually, this causes the set input of flip-flop 24 to change from low level to high level, and flip-flop 24 is set.

As a result, the high level output of the flip-flop 24 is inverted to the low level by the inverter 25 and guided to the NAND gate 26, so that the output of the NAND gate 26 is fixed to the high level. That is, a continuous high level output is guided to the base of the transistor T2,
2 is continuously turned on, and the LED 23 is continuously turned on.

Next, during this controllable ink supply, the main ink tank 1
When there is a sufficient amount of ink in 2 and ink is supplied, the ink level in the sub ink tank 4 rises above the position of the electrode pair 9.

As a result, the resistance Rx and the resistance value are lowered, and the comparator 1
The output of 7 changes from high level to low level again. The flip-flop 21 is reset, the AND gate 22 is closed, and the LED 23 is turned off by the same operation as the detection when the sub-ink tank 4 is sufficiently filled. By turning off the light, the operator is informed that there is sufficient ink in the main ink tank and ink has been supplied.

On the other hand, when the ink in the main ink tank 12 is exhausted, the resistance value of the resistor Rx continues to be infinite, the output of the comparator 17 remains at the high level, the flip-flop 21 is in the set state, and the AND gate. Since the open state of 22 is continued, the continuous lighting of the LED 23 is continued.

By the continuous lighting of the LED 23, the operator can know the ink shortage in the main ink tank 12. That is, the LE that has changed from intermittent blinking to continuous lighting at the start of the suction operation for forcibly supplying ink
If D23 is continuously lit even after the time required for the completion of the ink supply operation has passed, it means that the ink is not supplied to the sub-ink tank 4.
That is, the ink in the main ink tank 12 has run out. Since the time required to complete the above-mentioned supply operation is very short, the determination can be easily performed.

According to the above configuration, the warning that the amount of ink in the sub ink tank 4 is small is issued by blinking the LED 23 intermittently, and the warning that the main ink tank 12 is out of ink is indicated by the LED 23 for a predetermined time or longer. This is performed by the fact that the lights are continuously lit continuously, and it is extremely easy to distinguish between the two. Moreover, the detection means (electrode pair) and the alarm means (LED) for each one can detect the amount of ink in the two tanks and give an alarm based on the detection result.

In the present invention, the method of expressing the distinction between the LED alarms in the above embodiments is not limited to the above method, but may be the reverse of the above. Further, it may be configured such that a plurality of warning means can be used to distinguish the warnings. Further, the alarm means is not limited to the optical means such as the LED of the embodiment, and other means such as an acoustic means such as a buzzer may be used, and the liquid amount detecting means is not limited to the electrode pair.

Further, in the above-described embodiment, the ink supply operation may be automatically performed based on the detection output that the ink amount in the sub ink tank 4 is small. Further, although the operating switch 15a is the operating switch of the pump 15, it may be a switch interlocking with it.

Furthermore, the configuration of the present invention is not limited to the ink amount detection alarm device of the ink jet recording apparatus of the embodiment, but in an apparatus having a plurality of tanks that consume liquid and that are supplied with liquid from one side to the other as a storage tank for the liquid. It can be applied to all liquid amount detection alarm devices that detect the amount of liquid in the tank and give an alarm based on the detection result.

Effect As is apparent from the above description, according to the present invention, the nozzle for ejecting ink for recording and the main ink tank communicate with each other through the sub ink tank, and the sub ink tank to the nozzle is connected. A method for outputting an ink liquid amount abnormality alarm of an ink jet recording apparatus, in which ink supply and ink supply from the main ink tank to the sub ink tank are performed by a capillary phenomenon, and the ink in the sub ink tank has a predetermined amount. When the following occurs, a first alarm indicating that the ink volume is abnormal is output, ink is sucked from the tip of the nozzle, and ink is forcibly supplied from the main ink tank to the sub ink tank. , The ink in the sub ink tank is forcibly supplied even if the forcible supply of ink from the main ink tank to the sub ink tank is performed. If it is less than a predetermined amount, ink amount of the main ink tank is employed a configuration for outputting a second alarm that was reduced.

For this reason, an abnormality that cannot occur in the normal recording state of the printer described above, in which the ink in the sub ink tank becomes less than or equal to a predetermined amount even though a sufficient amount of ink is present in the main ink tank. First that the phenomenon has occurred
It can be known by the warning.

Further, according to the present invention, since the ink is sucked from the tip of the nozzle in response to the output of the first alarm, it is possible to remove the bubbles in the nozzle and fill the inside of the nozzle with the ink, which causes the above-mentioned worst situation. In addition, it is possible to prevent the non-ejection of ink.

Further, according to the present invention, the sub ink tank and the main ink tank are always communicated with each other, and the ink is supplied from the main ink tank to the sub ink tank at all times during the recording due to the capillary phenomenon, so that the normal recording is performed. As long as the state continues, as the ink droplets are ejected from the nozzle, the same amount of ink as the ejection amount is transferred from the main ink tank to the sub ink tank,
Since ink is naturally supplied until the amount of ink in the main ink tank falls below a specified amount, the ink is forcibly supplied from the main ink tank to the sub ink tank unless the above-mentioned abnormality occurs in the sub ink tank. No need.

Further, according to the present invention, when the ink in the sub ink tank is equal to or less than the predetermined amount even if the ink is forcibly supplied from the main ink tank to the sub ink tank,
The second reason that the amount of ink in the main ink tank has dropped
Since the warning is output, the phenomenon that the amount of ink in the sub ink tank is less than or equal to the predetermined amount is not due to an abnormality in the sub ink tank, but is due to the decrease in the amount of ink in the main ink tank. There is an excellent effect that the operator can recognize the distinction between the two.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a main part of an ink jet recording apparatus in which the ink amount detection / alarm device of the embodiment of the present invention is used, and FIG. 2 is a circuit diagram showing the configuration of the ink amount detection / alarm device of the embodiment. 1 ... Nozzle, 4 ... Sub ink tank 9 ... Electrode pair, 12 ... Main ink tank 15 ... Pump, 15a ... Actuating switch 17 ... Comparator, 18, 22 ... And gate 19, 25, 28 ...... Inverter, 20,26 …… Nand gate 21,24 …… Flipflop 27 …… Oscillator, Rx, R1 to R7 …… Resistors T1, T2 …… Transistor

Claims (3)

[Claims] 1. A nozzle for ejecting ink to perform recording and a main ink tank communicate with each other via a sub ink tank, the ink is supplied from the sub ink tank to the nozzle, and the sub ink is supplied from the main ink tank. A method for outputting an ink liquid amount abnormality alarm of an ink jet recording apparatus in which ink is supplied to an ink tank by a capillarity phenomenon, wherein the ink liquid amount is abnormal when the ink in the sub-ink tank is below a predetermined amount. A first alarm indicating that there is is output, ink is sucked from the tip of the nozzle, ink is forcibly supplied from the main ink tank to the sub ink tank, and the main ink tank transfers to the sub ink tank. If the amount of ink in the sub ink tank is less than or equal to the predetermined amount even after the forced ink supply operation, the main ink Ink amount abnormality alarm output method for an ink jet recording apparatus characterized by an ink amount in the ink tank to output a second alarm that was reduced. 2. An ink liquid amount abnormality alarm output method for an ink jet recording apparatus according to claim 1, wherein the first alarm and the second alarm are output by one alarm means. 3. A method of outputting an abnormal ink level alarm for an ink jet recording apparatus according to claim 1 or 2, wherein the first alarm and the second alarm are expressed by different expressions. .