JPH10278300A - Residual quantity of ink detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the residual quantity of ink through a simple circuitry even if the number of ink chambers is increased by connecting pairs of electrodes provided in a plurality of ink chambers electrically in series and measuring the level of current flowing through the series connection. SOLUTION: An electrode 12b facing an electrode 12a is connected with an electrode 12c, an electrode 12d facing the electrode 12c is connected with an electrode 12e, and an electrode 12f facing the electrode 12e is connected with the other terminal of a pulse voltage generator 14. Since respective ink chambers are connected electrically in series through the electrodes 12a-12f, a voltage generated from the pulse voltage generator 14 is applied between the electrodes 12a-12f. A current flowing between the electrodes 12a-12f is measured by means of a current measuring instrument 13. When the ink runs out between the electrodes 12a and 12b, 12c and 12d or 12e and 12f, total resistance is varied by a factor of 10 or more as compared with the case where the three spaces between electrodes are entirely filled with ink and the output value from the current measuring instrument 13 is also varied significantly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting the remaining amount of ink used in an ink jet recording apparatus or the like.

[0002]

2. Description of the Related Art Conventionally, an ink jet recording apparatus or the like is provided with an ink remaining amount detecting device for detecting the remaining amount of ink existing in an ink cartridge. A conventional example of the ink remaining amount detecting device will be described with reference to FIGS.

FIG. 3 is a block diagram of a remaining ink amount detecting device in a monochrome ink jet recording apparatus.
The monochrome type ink remaining amount detection device in FIG.
Ink cartridge 3 having one black ink chamber
1, an electrode pair 32, a current measuring device 33, a pulse voltage generator 34, a comparator 35, and an output terminal 36 for an ink detection result signal.

[0004] The operation of the conventional monochrome type ink remaining amount detecting device configured as described above will be described.

When the user gives an instruction to start ink detection from an operation unit (not shown) or a control unit (not shown) automatically gives an instruction to start ink detection, the pulse voltage generator 34
Generates a pulsed voltage and applies it between the electrodes 32 via a current measuring device 33. At this time, the current flowing between the electrodes 32 is measured by the current measuring device 33. There is a large difference between the case where the space between the electrodes 32 is filled with ink and the case where the space between the electrodes 32 is not filled. More than several tens of times. Therefore, a current value when the ink is not filled is measured and stored in advance, and a value equal to or more than this current value, for example, a value five times as large (hereinafter, referred to as A) is set.
The presence or absence of the remaining amount of ink is detected by comparing the current value at the time of detection (referred to as B). That is, when the current value B, which is the detection result of the current measuring device 34, is input to the comparator 35, the comparator 35 compares the values of A and B. If B is equal to or more than A, it is determined that “ink is present”. Is output. on the other hand,
If B is less than A, the comparator 35 sets “no ink” and outputs 0. The output signal of the comparator 35 is output to the outside via an output terminal 36.

Next, a description will be given of an ink remaining amount detecting device in a color ink jet recording apparatus with reference to FIG.

FIG. 4 is a block diagram of the ink remaining amount detecting device in the color ink jet recording apparatus. 4 is an ink cartridge 41 having three ink chambers of a yellow ink chamber, a magenta ink chamber, and a cyan ink chamber.
, Three electrode pairs 42, three current measuring devices 43, 3
Three pulse voltage generators 44, three comparators 45,
ND circuit 46 and output terminal 47 of the ink detection result signal
And is composed of

The operation of the conventional color type ink remaining amount detecting device having the above configuration will be described.

In the case of the color type, since there are three ink chambers of yellow, magenta and cyan, ink detection is performed for each ink chamber. That is, for each ink chamber, ink is detected as in the above-described monochrome type ink remaining amount detection device, and each comparator 4
5 outputs 1 or 0 to the AND circuit depending on the presence or absence of ink. As a result, the AND circuit 46 outputs 1 only when ink exists in all three ink chambers, and outputs 0 when there is at least one ink chamber where no ink exists. This output signal is output to the outside through an output terminal 47.

[0010]

However, the configuration of the color type ink remaining amount detecting device described above is merely a configuration in which a plurality of monochrome type ink remaining amount detecting devices are connected via an AND circuit. That is, an electrode pair for each ink chamber,
Since the pulse voltage generator, the current measuring device, and the comparator are provided, there is a problem that the circuit configuration becomes complicated as the number of ink chambers increases, and the scale of the entire remaining ink amount detection device increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a simple circuit configuration and can detect the remaining amount of ink, regardless of the increase in the number of ink chambers. It is intended to provide a device.

[0012]

According to one aspect of the present invention, there is provided an ink cartridge having a plurality of recording heads, an ink cartridge having a plurality of ink chambers, and a plurality of recording heads or a plurality of recording heads. An electrode pair provided in any one of the ink chambers, a current value measuring means for measuring a current value flowing by electrically connecting these electrode pairs in series, and an ink remaining amount in the ink chamber based on the current value. And an ink detection means for detecting

With such a configuration, in the color ink type ink remaining amount detecting device, even if the number of colors to be used increases and the number of ink chambers increases, the circuit does not become complicated,
The whole device can be made compact.

According to a second aspect of the present invention, in the ink remaining amount detecting device according to the first aspect, an electrode pair is provided at a joint between the recording head and the ink chamber.

With this configuration, it is possible to detect the presence or absence of ink at the portion where ink is supplied from the ink cartridge to the recording head. Therefore, the remaining amount of ink is detected at the portion of the ink cartridge where a member such as a sponge is interposed. The detection accuracy can be improved more than the above.

According to a third aspect of the present invention, in the ink remaining amount detecting device according to the first aspect, an electrode pair is provided in a common ink chamber of the recording head.

With such a configuration, the remaining amount of ink can be detected at the final consumption point of the ink, so that the detection accuracy can be improved and the ink can be used to the end without waste.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to FIGS.

(Embodiment 1) FIG. 1 is a block diagram showing a first embodiment of an ink remaining amount detecting apparatus according to the present invention.

In FIG. 1, an ink remaining amount detecting device according to the present invention detects an ink cartridge 11 having three ink chambers of yellow, magenta, and cyan, and supplies a current to each ink chamber to detect the remaining amount of ink. Electrode 12a for
To 12f, a current measuring device 13 for measuring a current value, a pulse voltage generator 14 for generating a pulsed voltage, a comparator 15 for comparing the measured current value with a predetermined threshold value, and an ink detection result. And an output terminal 16 for outputting to the outside.

Next, the operation of the first embodiment of the ink remaining amount detecting device configured as described above will be described.

The pulse voltage generator 14 generates a pulse voltage, and this voltage is supplied to the electrode 1 via the current measuring device 13.
2a. Electrode 12b facing electrode 12a
Is connected to the electrode 12c, the electrode 12d facing the electrode 12c is connected to the electrode 12e, and the electrode 12f facing the electrode 12e is connected to the other terminal of the pulse voltage generator 14. As described above, each ink chamber is provided with the electrodes 12a to 12a.
Since the electrodes are electrically connected in series via the electrode 12f, the voltage generated by the pulse voltage generator 14 is applied between the electrodes 12a to 12f. At this time, the current between the electrodes 12a to 12f is measured by the current measuring device 13.

Here, the resistance value between the electrodes 12a-12f is R, the resistance value between the electrodes 12a-12b is Ry, the resistance value between the electrodes 12c-12d is Rm, and the electrodes 12e-12
If the resistance value between f is Rc, R = Ry + Rm + Rc, and the output value of the current measuring device 13 is a value inversely proportional to this R.

The values of Ry, Rm, and Rc are Ry when ink is filled between the respective electrodes.
1, Rm1 and Rc1, and Ry2, Rm2 and Rc2 when the ink is not filled, Ry1 and Rm
1 and Rc1 have substantially the same value, and similarly, Ry2, Rm2, and Rc2 have substantially the same value.

That is, Ry1 ≒ Rm1 ≒ Rc1 Ry2 ≒ Rm2 ≒ Rc2.

Further, the resistance value when the ink chamber is not filled with ink is several tens times or more of the value when the ink chamber is filled. ≧ 10 (Ry1 + Rm1 + Rc
1)

Therefore, between the electrodes 12a and 12b, the electrode 12
When any of the electrodes c to 12d and the electrodes 12e to 12f have no ink remaining, the total resistance value R greatly changes by several tens of times compared to the case where all the three electrodes are filled with ink. However, the output value of the current measuring device 13 also changes greatly.

In view of this, a current value in a state where there is no remaining ink in any one of the three electrode pairs is measured in advance, and a predetermined multiple (for example, 5 times) of this current value is set as a threshold, and the ink value is measured. The amount of ink remaining is detected by comparing the magnitude of the current value with the threshold value during operation of the remaining amount detection device.

That is, the measured value of the current measuring device 13 at the time of the operation of the remaining ink amount detecting device is input to the comparator 15, and the measured value is compared with the above-mentioned threshold value. The comparator 15 outputs 1 as “ink remaining”, and outputs 0 as “ink remaining” if it is less than the threshold. This signal is output from the output terminal 16 to notify the presence or absence of the remaining ink amount to the outside.

(Embodiment 2) FIG. 2 is a cross-sectional view of an ink cartridge and a head section showing Embodiment 2 of an ink remaining amount detecting device according to the present invention.

In FIG. 2, the ink cartridge 21
Has a plurality of ink chambers as in the first embodiment. The recording head 22 includes a common ink chamber 23 and a pressure chamber 2.
4, a piezoelectric element 25, and a nozzle 26. The piezoelectric element 25 is distorted by the applied voltage. The volume of the pressure chamber 24 changes due to this distortion, and the ink is ejected. The electrode pair 27 is the same as that in the first embodiment, but is provided at the joint between the ink cartridge 21 and the recording head 22. Other configurations are the same as those in the first embodiment, and thus description thereof is omitted.

Usually, an electrode pair for detecting the remaining amount of ink is
Each ink chamber is installed in an ink cartridge portion. The ink cartridge contains a highly water-absorbing and water-permeable member such as a sponge in order to keep the liquid ink calm. For this reason, when trying to detect the remaining amount of ink by measuring the current value, a member such as a sponge may affect the detection result.

In the second embodiment, an electrode is provided at the joint for supplying ink from the ink cartridge to the recording head. In this way, when electrodes are installed at the junction between the ink cartridge and the recording head, only the target to be detected exists between the electrodes, and the remaining amount of ink is detected at the ink cartridge portion where a member such as a sponge is interposed. The detection accuracy can be improved as compared with the case of performing

There are two types of joints: a case where the recording head side is convex and joined to a concave portion on the ink cartridge side, and a case where the ink cartridge side is convex and joined to a concave portion on the recording head side. There is a form.

The electrode pair can be provided in a common ink chamber of the recording head in addition to the above. Even if the ink cartridge runs out of ink, printing can be performed if there is ink in the common ink chamber. Therefore, if the remaining ink amount is detected at the final consumption point of the ink, the detection accuracy can be further improved.

[0036]

As is apparent from the above description, according to the first aspect of the present invention, in the color ink type ink remaining amount detecting apparatus, the number of colors to be used increases and the number of ink chambers increases. Even so, the circuit is not complicated, and the entire device can be made compact.

According to the second aspect of the present invention, the presence or absence of ink can be detected at a portion where ink is supplied from the ink cartridge to the recording head. The detection accuracy can be improved as compared with the detection of the remaining ink amount.

According to the third aspect of the present invention, the remaining ink amount can be detected at the last consumption point of the ink, so that the detection accuracy can be improved and the ink can be used without waste until the end. be able to.

[Brief description of the drawings]

FIG. 1 is a block diagram of an ink remaining amount detecting device according to the present invention.

FIG. 2 is a cross-sectional view of an ink remaining amount detecting device according to the present invention.

FIG. 3 is a block diagram of a conventional ink remaining amount detecting device.

FIG. 4 is a block diagram of a conventional ink remaining amount detecting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Ink cartridge 12a-12f Electrode 13 Current measuring device 14 Pulse voltage generator 15 Comparator 15 Output terminal

Claims (3)

[Claims] An ink cartridge having a plurality of recording heads, a plurality of ink chambers provided corresponding to the plurality of recording heads, and one of the plurality of recording heads or the plurality of ink chambers. An electrode pair, a current value measuring means for measuring a current value flowing by electrically connecting these electrode pairs in series, and an ink detecting means for detecting the remaining amount of ink in the ink chamber based on the current value. An ink remaining amount detecting device, comprising: 2. The remaining ink amount detecting device according to claim 1, wherein the electrode pair is provided at a joint between the recording head and the ink chamber. 3. The apparatus according to claim 1, wherein the electrode pair is provided in a common ink chamber of the recording head.