JPH09309211A - Ink-detecting device for ink recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely determine whether ink is present by providing a means for supplying an alternating current as an electric current supply means, in a device designed for detecting whether the ink is present based on a voltage generated by an electrode when supplying the electric current to the electrode for detecting the ink arranged in an ink tank. SOLUTION: This ink detecting device for an ink recording device is equipped with a simulated AC output part 10 which generates a simulated AC, and generates a constant AC based on a simulated AC output from the simulated AC output part 10, and further, this AC is applied to an area between electrodes 104a, 104b in an ink tank 103. A stable DC output is obtained by holding the voltage between the electrodes 104a, 104b during the period of detecting a residual ink amount at the peak voltage of an AC input by a DC output conversion part 30. In addition, the stable DC output is converted to a digital signal by an A/D converter 32, and MPU 1 recognizes the presence of the ink in the ink tank 103 based on the digital signal. If the ink is not present, a no ink warning part 41 is activated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink detecting device for an ink type recording device, and more particularly to an ink detecting device for an ink type recording device in which electrodes are arranged in an ink tank and the presence or absence of ink is detected based on a potential difference between the electrodes. Regarding the device.

[0002]

2. Description of the Related Art In a conventional ink type recording apparatus (for example, a plotter apparatus or a printer apparatus) using an ink jet method, an ink tank provided in an ink head or an ink tank provided separately from the ink head is used. Ink is supplied to the ink ejection portion of the ink head to form an image. In this recording device, in order to prevent the ink in the ink tank from being emptied and the image formation being interrupted, the ink remaining amount is detected, and if the remaining amount is less than a predetermined amount, the ink tank or the ink The ink head with a built-in tank is replaced.

FIG. 10A shows a conventional ink detecting device 1.
00B, and FIG. 10B is a schematic perspective view of the ink tank 103 in the ink detection apparatus 100.

In FIGS. 10A and 10B, in the case of detecting the remaining ink amount, a DC output from the DC constant current circuit 102 according to an instruction from a control unit 101 composed of MPU, RAM, ROM and the like. When an electric current is applied between the two electrodes 104a and 104b provided in the ink tank 103, the inter-electrode voltage changes depending on the presence or absence of ink. This inter-electrode voltage is converted into an analog value into a digital value by using the A / D converter 105, and the control unit 101 "inter-electrode voltage when ink is present" and "inter-electrode open voltage when ink is not present".
The presence or absence of ink is detected by comparison with the above, and when it is detected that there is no ink, an alarm is issued from the ink out alarm unit 106.

Depending on the type of ink-jet type ink-jet recording apparatus, four-color ink heads (cyan, magenta, yellow, black) can be mounted on a carriage that scans the recording paper to perform full-color printing. Is. In this case, since it is necessary to mount the ink head of each color at the position of the carriage that is defined in advance, a color identification unit is provided to identify whether or not the ink head of the regular color is installed. As an example of this color identification means, as shown in FIG. 11, a fixed resistor 111 for color identification is arranged on the ink head 110, and when the ink head is set on the carriage, the resistance value of the resistance value is changed by the control unit of the recording apparatus. The color is identified for each ink head by detecting the difference.

[0006]

However, in the ink detection device 100, the electrical detection value of ink is not stable, and the ink remaining amount may be erroneously detected.

This will be specifically described. FIG. 12 is an electrical characteristic diagram of the ink in the ink detection apparatus 100. When the constant current of 200 μA is applied between the electrodes 104a and 104b in the ink tank 103 under the environment of room temperature (RT) 25 ° C. These are the actual measured values of the voltage when there is a charge and when there is no ink.

As is clear from this characteristic diagram, the ink remaining amount detection voltage when there is ink rises with the passage of time, and the difference from the voltage value when there is no ink is small. Therefore, it becomes impossible to determine the presence / absence of ink with the lapse of time, and it is easy to cause an erroneous detection of the presence / absence of ink. The reason is that the + -ions in the ink are polarized on both electrodes, and the resistance value increases with the passage of time, and the time during which the resistance value rises (that is, the rising curve in the case of "ink present"). ) Varies depending on various conditions such as the remaining amount of ink and is not constant.

A resistor 1 for identifying the color of the ink.
When 11 is provided on the ink head 110, the correspondence between the ink color and the ink head is required to be “1: 1”, and management is troublesome.

Therefore, an object of the present invention is to provide an ink detection device in an ink type recording device which can accurately identify the presence or absence of ink or the color identification.

[0011]

In order to solve the above-mentioned problems, the invention according to claim 1 is to provide an ink detecting electrode arranged in an ink tank for storing ink, and a current for supplying a current to the electrode. In the ink detecting device in the ink-type recording apparatus, the current detecting means includes an ink detecting means for detecting the presence or absence of ink based on a voltage generated by the electrode when the current is supplied from the current supplying means to the electrode. The supply means is composed of an alternating current supply means.

According to the first aspect of the present invention, since the current supply means is an alternating current supply means, the + -ions in the ink are not polarized and the resistance value does not increase. No more false positives.

Further, the invention according to claim 2 is characterized by comprising a smoothing means for smoothing the detection voltage between the electrodes.

According to the second aspect of the present invention, since the smoothing means smoothes the detection voltage between the electrodes (see FIG. 3), the ink detecting means accurately detects the presence or absence of ink based on the stable voltage. it can.

The invention according to claim 3 is provided with a table of electric conductivity corresponding to the ink color in the ink tank, and the color in the ink tank is discriminated based on the detection voltage between the electrodes. Is characterized by.

According to the third aspect of the invention, in the case of the color ink, the electrical conductivity differs depending on the color. Therefore, for example, a table of electric conductivity corresponding to magenta, cyan, yellow, and black is prepared, a current is applied from an alternating current supply means to detect a voltage between electrodes, and this voltage value is compared with the table. However, the color of the ink in the ink tank is determined at the same time when the remaining ink amount is detected without providing any special color identification means.

According to a fourth aspect of the present invention, there is provided an electric conductivity table corresponding to the ink color of the ink head mounted on the ink head mounting means in which the mounting order of the plurality of ink heads is defined, and the electrode is provided. It is characterized in that the mounting order of the ink heads mounted on the ink head mounting means is determined based on the detected voltage between them.

According to the fourth aspect of the present invention, the table stores the electric conductivity corresponding to the ink color of the ink head mounted on the ink head mounting means. The ink head mounting means has a predetermined order of colors to be mounted in advance. The color of the ink head mounted on the ink head mounting means is discriminated based on the detection voltage between the electrodes, and it is discriminated whether or not the color order is in the prescribed color order.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on an embodiment shown in the drawings. Note that the same reference numerals are given to the already described portions, and redundant description is omitted.

(1) First Embodiment Example FIG. 1 is a system block diagram of the present embodiment example. As shown in FIG. 1, the ink detection apparatus of the present embodiment is roughly divided into four parts, a pseudo AC output unit 10, a constant current circuit 20, the above-described ink tank 103, and a DC output conversion unit 30. It is configured.

The pseudo AC output unit 10 converts the clock pulse generated by the MPU 1 into an alternating current by the D / A converter 2 to generate a 100 Hz pseudo AC (pseudo alternating current).

The constant current circuit 20 generates an alternating constant current of 1.5 mA based on the pseudo AC output from the pseudo AC output section 10 and supplies the alternating current to the ink tank 103. By doing so, since an alternating current is applied between the electrodes 104a and 104b, the polarization of the ink as described in the prior art does not occur, and the ink remaining amount detection voltage is clear depending on the presence or absence of ink. There is a difference. For example, ink tank 1
Open voltage between electrodes (when there is no ink in 03) (A
C) is, for example, “4.3 V”, and when it is smaller than this value (for example, 1 to 3 V), it is determined that “ink is present”.

On the other hand, the voltage between the electrodes 104a and 104b is converted into a DC output by the DC output converter 30, and MP
Transfer the DC output to U1.

Here, the DC output converter 30 will be described in detail. The DC output converter 30 is configured to include a peak hold circuit 31 and an A / D converter 32, and a detailed circuit of the peak hold circuit 31 is shown in FIG.

As shown in FIG. 2, the peak hold circuit 3
1 is an operational amplifier OP1, a diode D1, and a capacitor C
It is composed of 2 etc., holds a positive peak voltage of alternating current (AC), and outputs it as a DC voltage.

FIG. 3 shows an AC-D conversion by the DC output converter 30.
It is the output figure which carried out C conversion. The voltage waveform of the AC input (that is, the output waveform of the constant current circuit 20) is the upper waveform in the figure, and the lower waveform in the figure is the waveform obtained by converting the AC input into the DC output by the DC output conversion unit 30. is there.

With this configuration, the DC output converter 30 holds the peak voltage of the AC input while detecting the remaining amount of ink, so that a stable DC output can be obtained. For example, when the AC input voltage to the DC output converter 30 is 4.3 V, the stabilized DC output (DC
The output conversion unit 30) has a voltage of about 3.1V.

Then, this stable DC output is converted into a digital signal by the A / D converter 32, and the MPU 1 recognizes the presence or absence of ink in the ink tank 103 according to the signal and controls it. For example, when it is detected that there is no ink, the no-ink alarm unit 41 issues an alarm (voice, L
ED display etc.).

The sequence of the MPU 1 will be described with reference to the flowchart of FIG. As shown in FIG. 4, when the operation mode of the ink remaining amount detection system is entered, initial setting is first made, and the process proceeds to the ink remaining amount detection sequence (step S
1). Then, when the presence or absence of ink in the ink tank is detected by passing a constant current through the pseudo AC output in the ink tank, and as a result it is determined that there is no ink in the ink tank (step S2; NO), the ink An absence warning is issued (step S3), and the process proceeds to the ink tank or ink head replacement sequence (step S4). Whether or not the user has replaced the ink tank is determined by detecting attachment / detachment of the ink tank with a micro switch, a sensor, or the like (step S5). After the replacement of the ink tank, the process proceeds to the ink remaining amount detection sequence shown in step S1 again, and if it is determined that there is ink in the ink tank, the process ends.

If there is ink in step S2 (step S2; YES), the process ends without replacing the ink tank.

(2) Second Embodiment Example This embodiment example is a case where the color discrimination of the ink head is performed. The difference between this embodiment example and the first embodiment example is that the DC power is different in this embodiment example. The point is that the color identification circuit 33 is added to the conversion unit 30A.

FIG. 5 is a system block diagram of this embodiment. In FIG. 5, the color identification circuit 33 identifies whether the ink color in the ink tank is a predetermined ink color based on the DC output of the constant current circuit 20.

The color identification circuit 33 will be described with reference to FIG. The circuit of FIG. 6 is installed for each ink tank, and the variable resistance of VR1 is adjusted to the resistance value corresponding to the value of the electric conductivity of the ink, and the obtained voltage value is used as the judgment voltage.
Then, the DC output voltage from the peak hold circuit 31 and the judgment voltage are compared by the comparator COMP1, the output signal is converted into a digital signal by the A / D converter 32, and the MPU1 changes the ink color of the ink tank. Control is performed by determining whether the color is a predetermined color. If the ink is not a predetermined color, the ink abnormality alarm unit 42 issues an abnormality alarm.

As is well known, the electric conductivity is the reciprocal of the electric resistance per unit length of a substance, and the larger this value is, the easier the electric current flows through the substance. The ink is a conductive material and has a specific electric resistance value corresponding to the color. The color of the ink is identified by using this unique electric resistance value. The unit of electric conductivity is mS / cm (millisiemens / centimeter).

An example of the actual measurement value (voltage between the electrodes 104a and 104b) of the remaining amount detection voltage when the color ink is used is as follows. However, from the constant current circuit 20 to 1.5
This is the case when mA is supplied. Bk 1.2 (V) C 2.9 (V) M 1.6 (V) Y 2.5 (V)

Next, the sequence of the MPU 1 will be described with reference to the flow chart shown in FIG. As shown in FIG. 7, when the operation mode of the ink remaining amount detection system is entered, initial setting is first made, and the process proceeds to the ink remaining amount detection sequence (step S11). Then, the presence / absence of ink in each ink tank is detected by applying a constant current to the pseudo AC output in the ink tank, and when it is determined that there is no ink in the ink tank (step S12; NO), the ink is detected. An abnormal alarm is generated (step S13), and the process proceeds to the ink tank or ink head replacement sequence (step S13).
14). Whether the ink tank has been replaced by the user (step S15) is determined by detecting the attachment / detachment of the ink tank with a micro switch, a sensor, or the like.
to decide.

After the ink residual detection sequence, the process proceeds to the color identification sequence (step S16), and the voltage value obtained by flowing the pseudo AC output into the ink tank is the electrical conductivity of the ink. The color identification circuit 33 determines whether or not the corresponding voltage value exists.
If the result obtained by the color identification circuit 33 is out of the predetermined voltage value range (step S17: NO), step S1
3, the ink abnormality alarm is generated and the ink tank replacement sequence is entered (steps S13 and S1).
4). If the result obtained by the color identification circuit 33 is within the predetermined voltage value range (step S17; YES),
Recognizes that the ink in the set ink tank is the correct color, and ends.

(3) Third Embodiment Example FIG. 8 is a system block diagram of the present embodiment example. The difference between the present embodiment example and the first embodiment example is that a latch circuit 34 is added to the DC power conversion unit 30B in the present embodiment example, and this embodiment example has four colors in the case of full color printing, for example. This is a case where it is determined whether or not the ink heads containing the (magenta, yellow, cyan, black) ink tanks are set in the carriage in the correct order.

After the DC output of the constant current circuit 20 is converted into a digital value by the A / D converter 32, the value is stored in the latch circuit 34, and the magnitude relationship of the digital value of the ink in each ink tank is predetermined. It is compared whether it matches the magnitude relationship of the voltage. That is, four color ink heads (magenta, yellow, cyan, black)
If they are set in the correct order, the order of the voltage values of the electrodes corresponding to each color is known in advance. Whether or not the arrangement of the ink heads is correct is determined by matching the order of the voltage values. If they do not match in a predetermined order, the ink head abnormality alarm unit 43 issues an alarm.

Here, the control sequence of the MPU 1 will be described with reference to the flowchart of FIG. First, when the operation mode of the ink remaining amount detection system is entered, initial setting is first made, and the process proceeds to the ink remaining amount detection sequence (step S21). Then, the presence / absence of ink in the ink tank of each ink head is detected by supplying a constant current to the pseudo AC output in the ink tank, and as a result, it is determined that there is no ink in the ink tank (step S
22; NO), an ink head abnormality alarm is generated (step S23), and the process proceeds to the ink head replacement sequence (step S24). Whether the ink head has been replaced by the user is determined by detecting the attachment / detachment of the ink head with a micro switch, a sensor, or the like.

After the ink residual detection sequence (step S2
5: YES), the process proceeds to the ink head matching sequence (step S26), and it is determined whether the set positions of the set ink heads are set in the correct order (step S27). The pseudo AC output is set in the ink tank of the ink head. It is determined by whether or not the magnitude relationship of the digital values of the voltage values obtained by flowing is established. If the set ink heads are not arranged in the correct order (step S27; NO), an ink head abnormality alarm is issued in step S23, and the process proceeds to the ink head replacement sequence (steps S23 and S24). When it is recognized that the set ink heads are arranged in the correct order (step S27; YES), the process ends.

[0042]

As described above, according to the invention described in each of the claims, the presence or absence of ink can be clearly detected because an alternating current is supplied to the electrodes in the ink tank, and the smoothing means can be used to smooth the gap between the electrodes. Since the detected voltage is smoothed and the voltage is stabilized, the presence or absence of ink can be detected based on the accurate voltage.

Further, a table of electric conductivity corresponding to the ink color in the ink tank is provided, the color in the ink tank can be discriminated based on the detection voltage between the electrodes by referring to this table, and It is possible to determine whether or not the order of mounting the ink heads by the ink head mounting means is correct.

[Brief description of drawings]

FIG. 1 is a system block diagram of a first embodiment example of the present invention.

FIG. 2 is a circuit diagram of a peak hold circuit according to the first embodiment.

FIG. 3 is an output diagram of AC-DC conversion in the first embodiment example.

FIG. 4 is a flowchart of the first embodiment example.

FIG. 5 is a system block diagram of a second embodiment example of the present invention.

FIG. 6 is a circuit diagram of a color identification circuit according to the second embodiment.

FIG. 7 is a flowchart of the second embodiment.

FIG. 8 is a system block diagram of a third embodiment example of the present invention.

FIG. 9 is a flowchart of the third embodiment example.

10A is a system block diagram of a conventional example, and FIG. 10B is a schematic perspective view of an ink tank.

FIG. 11 is a perspective view of a color ink head.

FIG. 12 is a graph of a DC characteristic of an ink remaining amount detection voltage of a conventional example.

[Explanation of symbols]

 1 MPU (ink detection means) 2 D / A converter 10 Pseudo AC output section (AC supply means) 20 Constant current circuit (AC supply means) 30 DC output conversion section 31 Peak hold circuit (smoothing means) 32 A / D converter 33 color identification circuit 34 latch circuit 41 ink-less alarm unit 103 ink tanks 104a, 104b electrodes

Claims (4)

[Claims] 1. An electrode for ink detection arranged in an ink tank for storing ink, a current supply means for supplying a current to the electrode, and an electrode when a current is supplied from the current supply means to the electrode. In an ink detecting apparatus in an ink recording apparatus including an ink detecting unit that detects the presence or absence of ink based on a voltage generated by the, the current supplying unit includes an alternating current supplying unit in the ink recording apparatus. Ink detection device. 2. The ink detection device in an ink type recording apparatus according to claim 1, further comprising a smoothing unit that smoothes a detection voltage between the electrodes. 3. The table according to claim 1, further comprising a table of electric conductivity corresponding to ink colors in the ink tank, wherein the color in the ink tank is discriminated based on a detection voltage between the electrodes. Detection device in the ink recording device of. 4. An electric conductivity table corresponding to the ink color of the ink head mounted on the ink head mounting means in which the mounting order of a plurality of ink heads is defined, and the ink based on the detection voltage between the electrodes. 2. The ink detecting device in an ink recording apparatus according to claim 1, wherein the mounting order of the ink heads mounted on the head mounting means is determined.