JP2001121681A - Printer and ink container used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately achieve an ink residue graspably before an ink deficiency occurs and to perform such numeric measurement of the ink residue by a simple method. SOLUTION: An ink residue measuring unit 5 obtains the electrostatic capacity value Cv of an electric capacitor Cv based on the oscillation frequency of a voltage waveform detected by an electric capacity detector 4, and then obtain an ink residue value V corresponding to the value Cv. Regarding information indicating the corresponding relationship or functional relationship between the value Cv and the value V, various types of experiments or the like are previously conducted, and the corresponding relationship between the value Cv and the value V is grasped, and the value V is obtained at that time from the value Cv based on the information of the corresponding relationship.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a printing apparatus and an ink container used for the printing apparatus.

[0002]

2. Description of the Related Art In a printing apparatus such as a stencil printing apparatus in which an ink container containing a printing ink is exchangeably mounted, when the ink in the ink container is almost completely used, the empty space is used. Is taken out and disposed of, and a new ink container filled with ink is mounted, and printing is resumed. Alternatively, there is a case where the ink container which has been used up and is once emptied is filled with the ink again, and the ink container is mounted again on the printing apparatus for use.

[0003] In either of such a disposable (single-use) type or reusable type ink container, if the remaining amount of the ink is not checked, the ink may run out unexpectedly at an unexpected time. In response to this, preparations such as replacement of the ink container or replenishment of the ink cannot be dealt with, and during that time, the operation of the printing apparatus must be stopped. Therefore, originally, in a printing apparatus such as stencil printing, one of the most effective advantages is that the time efficiency of the printing operation is high. However, such an advantage is hindered by the ink shortage described above. Would be. Therefore, there is a strong demand for confirming the condition just before the ink runs out or before the remaining amount of the ink becomes small.

[0004] For this purpose, the simplest possible countermeasure is to allow the user to visually check the remaining ink amount. In practice, however, the ink container is generally mounted at a deep position inside the printing apparatus. Therefore, the user temporarily stops the operation of the printing apparatus, removes the ink container from the printing apparatus to a visible position, and further opens the ink container lid to open the ink level of the ink inside. Position of the ink container, or if the ink container is made of a translucent material, etc., visually check the remaining amount of ink inside through the translucent side wall etc. Is necessary, and such a series of operations are
It is extremely troublesome for the user to perform only to check the ink remaining amount.

Therefore, a method for confirming that the remaining amount of ink inside the printing apparatus has been reduced while the ink container is mounted in the printing apparatus has been conventionally proposed or used.

[0006] One of the typical techniques is as follows.
In a printing device that sucks ink from a container using an ink pump and supplies the ink to a plate cylinder or the like, if the ink is not sucked even when the ink pump is operating, the ink is It is a method of determining that the remaining amount is almost exhausted.
No. 61739.

Secondly, a light emitting / receiving device is provided at the end of the ink container or the like, and light is irradiated toward an inner cover for scraping ink in the container, and the light is reflected by the inner cover. A method of measuring the amount of movement of the inner lid based on the amount of reflected light that has returned and calculating the remaining amount of ink corresponding to the amount of movement has been proposed in, for example, Japanese Patent Laid-Open No. 6-199371. I have. Alternatively, when a translucent ink container is used, a method of optically detecting the amount of ink inside from outside has been proposed. In this method, the remaining amount of ink is detected in a stepwise manner, for example, whether the container is full of ink, remains above a predetermined remaining amount, or is less than the predetermined remaining amount.

[0008]

However, in the above-mentioned first conventional method, the presence or absence of ink in the container can be detected in a binary manner, but the remaining amount of ink is quantitatively measured. Can not do. As a result, the user cannot grasp the information on the remaining amount of the ink until the ink runs out substantially, so that when the ink runs out, it is not possible to respond with sufficient margin There is a problem that there is.

In the above-described first conventional method, it is possible to quantitatively measure the remaining amount of ink, but in practice, it is possible to accurately detect only the light reflected by the inner lid. Do not mean. That is, the light irradiated for measurement is often reflected not only on the inner lid but also on the side wall surface in the ink container, and the horizontality of the inner lid is not always kept strictly. Therefore, noise is often generated (mixed) in the reflected light due to these. As a result, there is a problem that the accuracy of detecting the remaining amount of ink is reduced.

The present invention has been made in view of the above points, and realizes a more accurate numerical measurement of the remaining amount of ink than before so that the amount of remaining ink can be reduced before an out-of-ink state occurs. The task is to be able to accurately determine the quantity.
Moreover, it is an object to achieve such a numerical measurement of the remaining amount of ink by a simple method.

[0011]

According to the present invention, there is provided a printing apparatus comprising: printing means for printing on a printing medium; and an ink container containing ink used for the printing. And at least two electrodes that are arranged to face each other with the ink container interposed therebetween and form an electric capacitor using at least the ink in the ink container as a dielectric, and a capacitance or a capacitance related to the electric capacitor. An electric capacity detecting means for detecting an electric signal corresponding to at least one of a dielectric constant and an impedance; and an ink remaining amount remaining in the ink container in accordance with the detected electric signal. And an ink remaining amount measuring means for measuring the remaining amount of ink.

The ink remaining amount measuring means prepares in advance information indicating a correspondence between the detected electric signal and the value of the ink remaining amount, and based on the information, the information indicating the correspondence between the detected electric signal and the value of the ink remaining amount is prepared. The value of the remaining ink amount may be obtained in association with the signal.

In the case where the ink container has a discharge port for discharging ink, and the printing apparatus includes a receiving metal fitting to which the discharging port is mounted, the receiving metal fitting is provided. May be used as one of the electrodes.

Alternatively, a component of the printing apparatus, which is made of a conductive material adjacent to the ink container, may be used as one of the electrodes.

Further, at least one of the opposed electrodes is divided into two or more small electrodes, and the electric signal is detected for each of the divided small electrodes. The remaining amount of ink in the ink container may be measured stepwise at least for each of the small electrodes based on the electric signal from each of the small electrodes.

[0016] The ink container of the present invention comprises a printing means for printing on a printing medium, an ink container containing ink used for the printing, and a pair of ink containers opposed to each other via the ink container. Two or more electrodes arranged to form an electrical capacitor using at least the ink in the ink container as a dielectric, and at least one of capacitance, dielectric constant, or impedance related to the electrical capacitor. And an electric-capacity detecting means for detecting an electric signal corresponding to the value of the ink container, and an ink-remaining-amount measuring means for measuring the remaining ink amount remaining in the ink container in accordance with the detected electric signal. An ink container for use in a printing apparatus, wherein at least one of the electrodes is provided on a surface of the ink container.

The present invention is particularly suitable for a stencil printing apparatus in which an ink container is detachably mounted and stencil printing is performed on a printing medium using ink supplied from the ink container. However, it is needless to say that the present invention is not limited to this, and the present invention is applicable to various other printing apparatuses.

[0018]

According to the present invention, an electric capacitor, that is, an electric capacity (in other words, a capacitor in an equivalent circuit) is formed by the opposing electrodes and the ink container sandwiched therebetween, and a physical quantity relating to the electric capacity, that is, a static amount. The capacitance, the dielectric constant, or the impedance is measured, and the value of the remaining ink amount is obtained based on the measured value. As a result, it is possible to measure the remaining amount of ink accurately (basically linearly) while making it possible to use a general existing ink container and the ink therein. Users will be able to accurately grasp the quantitative information on the remaining amount, and it will be possible to respond with sufficient margin for running out of ink, and thus the printing operation time due to sudden running out of ink etc. in a stencil printing machine etc. The efficiency can be prevented from lowering.

Further, by using a metal part such as a lid or a base at the end in the front-rear direction conventionally provided in the ink container as one of the electrodes, the structure can be further simplified. .

Further, by diverting some of the components of the printing apparatus as the electrodes, the structure can be further simplified.

Further, according to the present invention, if one electrode is divided into a plurality of small electrodes and provided, the remaining ink amount can be measured in a multi-step evaluation (discrete amount). .

Also, a label or the like is often attached to the surface of the ink container to clearly indicate information such as brand and type of the ink contained in the ink container. By using a conductive material such as an aluminum thin plate or an aluminum sheet, and also using it as an electrode used to construct an electric capacitor as described above, it is possible to further simplify the structure of the device including them. By attaching electrodes to the surface of the ink container in this way,
Since the positional relationship between the electrode and the ink container (surface of the container) can be fixed easily and reliably, the remaining ink amount can be measured more easily and reliably.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

(Embodiment 1) A printing apparatus for stencil printing (hereinafter referred to as a stencil printing apparatus) is, as shown in FIG.
A printing mechanism (printing means; not shown) having a plate cylinder and a printing paper transport mechanism for performing stencil printing on a printing medium (not shown) such as a printing paper or a transparent sheet for OHP.
And an ink container 2 containing the printing ink 1 therein, wherein the ink container 2 and the ink 1 inside the ink container 2 are used as a dielectric when the ink container 2 is mounted. Electric capacitor (Cv in the figure)
Are formed along the side surface of the ink container 2 so as to form Cv, that is, an electric capacitance, and are arranged to face each other via the ink container 2 containing the ink. Two electrodes 3a and 3b, an electric capacity detecting section (electric capacity detecting means) 4 for detecting an electric signal corresponding to the capacitance value Cv relating to the electric capacitor Cv, and ink based on the detected electric signal. Container 2
The main part is composed of an ink remaining amount measuring unit (ink remaining amount measuring means) 5 for obtaining a measurement result of the ink remaining amount V in the inside and a display unit 6 for displaying the measurement result on a screen such as a liquid crystal display panel. Have been. Since a general printing mechanism may be used in the above configuration, a detailed description and illustration thereof will be omitted.

The ink container 2 itself, that is, the bottle 2 ′ itself is made of a material such as polyethylene or polyester, which is not likely to be materially (chemically) affected by the ink 1 or its solvent. The outer shape is a cylindrical shape with both ends closed, and a discharge port for ink 1 is formed on one end face, and the ink 1 contained inside is discharged from the discharge port. Is set to The outer shell of the ink container 2 itself, that is, the shape and structure of the bottle 2 'and the ink 1
As for the material and the like, generally used materials may be used. Rather, it is an advantage of the present invention that even if the ink container 2 containing such general ink 1 is used as it is, the remaining amount of ink can be accurately measured by a simple method. From the viewpoint that one of the advantageous effects (advantages) can be obtained, it is more desirable that the conventional general settings can be used for the setting of the bottle 2 ′ and the ink 1. Therefore, also in the case of the present embodiment, the ink container 2 (bottle 2 ′ and ink 1 stored therein) having such a general shape, structure, and material is used.

As the material of the bottle 2 'of the ink container 2, it is possible to suitably use the relatively inexpensive materials generally used in the past, as described above, but almost all of them are used. When the entire surface is made of a conductive material such as metal, the inside of the bottle 2 'itself is electrostatically shielded, so that it is practical to apply the method of the present invention. Will be difficult.

The two electrodes 3a and 3b are formed in a plate shape curved so as to conform to the cylindrical outer shape of the ink container 2. When the ink container 2 is mounted at a predetermined position. Are arranged to face each other so as to form an electric capacitor via the ink container 2. That is, these two electrodes 3a, 3b and the ink container 2 (bottle 2 'and ink 1 inside thereof) interposed therebetween.
Thus, an electric capacitor Cv is formed.

The electric capacity detecting section 4 detects an electric signal corresponding to the capacitance Cv of the electric capacitor. As a more detailed electric circuit main configuration of the electric capacity detection unit 4, as shown in FIG. 2, a self-excited oscillation circuit using a transistor (Tr) 402, the oscillation output voltage waveform of which is shown in FIG. An electric capacitor Cv (that is, the ink container 2 containing the ink 1) via the electrodes 3a and 3b.
, The voltage waveform (i.e., oscillation frequency) of the entire circuit including the electric capacitor Cv changes in accordance with the capacitance value Cv of the electric capacitor Cv. As a result, a voltage waveform in which the oscillation frequency changes is detected as an electric signal, and the detected signal is sent to the remaining ink amount measuring unit 5. It goes without saying that the oscillation frequency of the voltage waveform detected at this time is determined according to the capacitance Cv of the electric capacitor Cv.

The ink remaining amount measuring unit 5 obtains the capacitance value Cv of the electric capacitor Cv based on the oscillation frequency of the voltage waveform detected by the capacitance detecting unit 4, and then obtains the capacitance value. An ink remaining amount value V corresponding to Cv is obtained. Regarding such information indicating the correspondence or functional relationship between the capacitance value Cv and the remaining ink value V, the outer shape and dimensions of the ink container 2 or the material of the ink 1 itself are generally standardized. Also, since data such as the dielectric constant per unit volume of the ink 1 determined based on such setting conditions can be fixedly grasped in advance, the capacitance value Cv can be determined by performing various experiments in advance. The correspondence with the remaining ink value V is grasped in advance. Then, based on the information on the correspondence, the remaining ink value V at that time may be calculated from the capacitance value Cv. Alternatively, information such as a table indicating the correspondence between the capacitance value Cv and the remaining ink value V is determined in advance based on experimental results and the like, and the detected capacitance value Cv is determined based on the table. May be obtained.

Here, it will be simply analyzed that it is theoretically possible to obtain the remaining ink value V from the capacitance value Cv detected as described above. The electric capacitor Cv composed of the ink container 2 containing the ink 1 and the electrodes 3a and 3b as shown in FIG.
Can be regarded as schematically shown in FIG. That is, an electric capacity Ca using air as a dielectric (ie, an electric capacity having a dielectric constant ε of air) Ca and an electric capacity using an ink 1 as a dielectric (ie, an electric capacity having a dielectric constant ε ′ of the ink 1) C
i can be regarded as being electrically equivalent to a circuit connected in parallel. Therefore, the overall capacitance value of the electric capacitor Cv is Cv = Ca + Ci.

Now, assuming that the widths w of the electrodes 3a and 3b are constant, as shown in FIG. 3, the height of the liquid surface of the remaining ink 1 (or the distance from the end face provided with the discharge port to the inner lid). ) Is defined as r, the electric capacity C of the air as a dielectric, which is the electric capacity of the space portion increased by using the ink 1.
As for a, the area Sa is Sa = (L−r) · w. Therefore, the value of the electric capacity Ca at this time is:
Assuming that the average distance between the opposing electrodes 3a and 3b is d, C
It can be written as a = ε · Sa / d = ε · (L−r) · w / d. On the other hand, the electric capacity Ci where the ink 1 is a dielectric is the electric capacity of the portion where the ink 1 remains.
, The area Si is Si = r · w, and the distance between the opposing electrodes 3a and 3b is d as in the case of Ca. Therefore, the value of the electric capacity Ci at this time is C
It can be written that i = ε ′ · Si / d = ε ′ · r · w / d.

Then, the electric capacitor C as a whole is
Since the capacitance value Cv of v is Cv = Ca + Ci as described above, therefore, Cv = {ε · (L−r) · w / d} +
｛Ε ′ · r · w / d｝ = (w / d) · ｛(ε′−ε) ·
r + ε · L｝. By the way, this is w / d, ε-ε
, Ε ′ · L are all constants, and they are arranged and appropriate constants (A, B; A = (w / d) · (ε′−ε),
B = (w / d) · (ε · L)), Cv =
A · r + B, which indicates that the capacitance value Cv of the electric capacitor Cv is represented by a linear expression of the displacement amount r of the liquid surface position of the ink 1 (that is, a variable relating to the remaining ink amount V). In addition, at this time, since the dielectric constant ε ′ of the emulsion ink 1 generally used for stencil printing is larger than the dielectric constant ε of air, when it is considered that ε << ε ′, A,
If B is approximately represented by A ′ and B ′, respectively, A ′ = (w
/ D) · ε ′, B ′ = 0, so that the above Cv is approximately Cv = A ′ · r, and that Cv and r are in a proportional relationship with the proportionality constant being A ′. become. Therefore, from such an analysis result, it is understood that there is a linear correspondence between the capacitance value Cv of the electric capacitor Cv and the remaining ink amount V.

Actually, the ink container 2 (bottle 2 ′) of the specification (external shape, size and material) generally used is used.
Between the capacitance value Cv actually detected in the above-described apparatus configuration using the ink 1) and the remaining ink value V calculated from the liquid level height r actually measured at that time. Confirmed the relationship. More specifically, an ink container 2 containing RISOGRAPH INK (trade name) manufactured by Riso Kagaku Kogyo Co., Ltd.
And the outer dimensions of the electrodes 3a and 3b are 2
The electrodes 3a and 3b having a planar shape of 20 × 70 mm, which are substantially rectangular and three-dimensionally curved along the cylindrical side surface of the ink container 2, have an oscillation frequency centered on 5 MHz. Under such a condition that the area becomes a stencil area, the function of the stencil printing apparatus according to the present embodiment is driven to measure the capacitance value Cv of the entire ink container 2 including the ink 1 and to measure the ink value of the ink 1 at that time. An experiment was conducted in which an actually measured value of the remaining ink value V was measured.

As a result, as shown in FIG. 4, extremely good linearity is established in the correspondence between the measured capacitance value Cv and the actually measured remaining ink value V which is the actual value. I was able to confirm that. Therefore, according to such experimental results, the proportionality constant determined by the overall compatibility of the material of the ink 1 or the bottle 2 ′ of the ink container 2, the electrodes 3 a, 3 b, and the capacitance detecting unit 4 (the above-described constant). In the analysis example, A or A ′) is multiplied by the detected capacitance value Cv.
Obtains (calculates) the ink remaining amount value V corresponding thereto from
It turns out that it is possible. Therefore, in the ink remaining amount measuring unit 5 according to the present embodiment, the above-described proportional constant is determined in advance based on an experimental result and the like, and a proportional operation using the constant is performed to calculate the proportional constant from the capacitance value Cv. The corresponding ink remaining amount value V is calculated.

However, the capacitance value actually detected from the entire ink container 2 (ink 1 and bottle 2 ') includes the capacitance of the bottle 2' itself. Since such a bottle 2 'has an electrical property inherent to its own material, the capacitance value detected from the bottle 2' is constant regardless of the amount of ink remaining in the bottle. . Therefore, when the capacitance of the bottle 2 ′ itself is a value that cannot be ignored, the capacitance value detected from such a bottle 2 ′ itself is grasped in advance by experiments or the like. The correction may be performed such that the value is subtracted from the capacitance value Cv detected from the entire ink container 2.

The remaining ink value V thus obtained
Is displayed on a screen using a liquid crystal display panel or the like of the display unit 6,
For example, it is displayed as "the remaining amount of ink is 100 cc". Alternatively, the ratio of the value V of the amount of remaining ink to the maximum capacity of the ink container 2 is further converted to% display,
For example, it may be displayed as “the remaining amount of ink is 25%”.
Alternatively, the ink capacity may be graphically displayed, for example, by converting the value V of the remaining amount of ink into data for displaying a bar graph, and displaying the remaining amount V of the ink in a bar graph using the data. As for such a display method, using a general display device, as shown in the example above, a combination of numerical values and characters, a graphic display, etc. are displayed so that the user can grasp the remaining amount of ink quantitatively. Needless to say, any method may be used as long as the method is used.

In the present embodiment, the relationship between the capacitance value Cv and the remaining amount of ink V determined by the shape of the electrodes 3a and 3b, the installation state thereof, the shape of the ink container 2, and the like is proportional. Although an example has been described, it is needless to say that the technique of the present invention is not limited to the case where the correspondence between the capacitance value Cv and the remaining amount of ink V is in such a proportional relation. In addition, when the capacitance value Cv changes, for example, as a quadratic function with respect to the remaining ink amount V due to various characteristics such as the shape of the ink container 2 and the shapes of the electrodes 3a and 3b. In such a case, such a quadratic correspondence is grasped in advance through experiments or the like, and data carrying information on the correspondence is stored in, for example, an RO.
M (semiconductor storage element), and a function operation based on the data is performed on the detected capacitance value Cv, and the remaining ink amount corresponding to a quadratic function is obtained. Should be obtained.

(Embodiment 2) In this second embodiment,
As shown in FIG. 5, the capacitance detecting unit 4 includes an AC generator 401 in a main part thereof, and the AC generator 401 generates an AC current Is having a constant frequency ω. When the alternating current Is is forcedly oscillated from outside to an electric capacitor Cv formed by the electrodes 3a and 3b and the ink container 2 (bottle 2 'and ink 1), the electric capacitor Cv Capacitance C
An AC voltage Vs that changes corresponding to v is detected. In other words, the AC voltage Vs changes in accordance with the impedance of the electric capacitor Cv at that time. Therefore, based on the measured value Vs of the AC voltage Vs, the measured value Is of the known AC current Is, and the value ω of the predetermined frequency ω, the value V of the remaining ink amount at that time can be obtained. The calculation for obtaining the remaining ink amount from the AC voltage is performed by the remaining ink amount measurement unit 5.

Here, the theoretical outline of the calculation performed by the ink remaining amount measuring unit 5 will be described. The capacitance Cv of the electric capacitor Cv can be expressed as Cv = Is / Vs · ω. That is, when an alternating current Is is forcibly applied to the electric capacitor Cv from the outside, an impedance Z due to the electric capacitor Cv is generated.
The value Z of the impedance Z can be expressed as Z = 1 / ω · Cv. On the other hand, the detected AC voltage Vs
Is given by Vs = Is · using the value Z of the impedance Z.
Z can be represented. To summarize these, Cv = I
s / Vs · ω. Where ω and I
Since s is a constant value, its numerical value is previously confirmed as a constant, and since Vs is detected from the actual electric capacitor Cv, its value is grasped numerically. Therefore, the capacitance value Cv of the electric capacitor Cv can be obtained based on these values, and the value V of the remaining ink amount corresponding to the capacitance value Cv is calculated in the same manner as in the first embodiment. Can be obtained by performing a function operation.

In this manner, the alternating current Is is applied to the electric capacitor Cv, and the electric capacitor Cv
v, an impedance Z is generated, and a value V of the remaining ink amount can be obtained based on the capacitance value Cv of the electric capacitor Cv measured corresponding to the impedance Z at that time. Moreover, the method of measuring the remaining ink value V in this manner can be realized by an extremely simple circuit system as shown in FIG.

(Embodiment 3) In the third embodiment,
As shown in FIG. 6, one electrode 3b is a so-called common electrode, and the other electrode 3a is a plurality of small electrodes 301, 302, 3 among a pair of electrodes arranged to face each other.
It is divided into 03, 304, and 305, and is set so that an electric signal is detected for each of the small electrodes. And each of these small electrodes 301, 302,.
Based on the electric signal detected from 5, the remaining ink amount measuring unit 5 measures (determines) at which small electrode position the ink 1 remains.

That is, more specifically, the divided electrode 3a has a total of five small electrodes 301, 302,
303, 304, and 305, and the electric capacity detecting sections 4 respectively correspond to the section electric capacity detecting sections 41, 42, 43, 44, and 4 corresponding to the respective small electrodes.
5 are supplied with an alternating current in the same manner as in the second embodiment, and the individual small electrodes 301 and 3 are provided.
, 305 are individually detected from the AC voltage. Then, the remaining ink amount measuring unit 5 compares each of the detected AC voltages Vs with a predetermined threshold value Vth, and when Vs is larger than Vth, the small electrode is positioned. It is determined that ink 1 is present in the section where the small electrode is located, and if Vs is smaller than Vth, it is determined that ink 1 is not present in the section where the small electrode is located. Is determined. Such determination can be made for each individual small electrode, and the remaining ink amount at that time can be obtained stepwise (as a discrete quantity) based on the entire determination result.

In the case of this embodiment, the remaining ink amount is evaluated in five steps using the small electrodes 301, 302,... 305 divided into five parts. For example, in FIG. When an AC voltage satisfying Vth <Vs is detected from the three small electrodes 301, 302, and 303, and an AC voltage satisfying Vth> Vs is detected from the remaining two small electrodes 304 and 305, ink The remaining amount V is 60% at present when the full state before use is 100%.
(= 3/5). Based on the measurement result obtained in this way, the position of the ink 1 remaining in the five stages on the screen of the display unit 6 is displayed by, for example, a bar graph or the like. The remaining ink amount V can be indicated to the user in a discrete but quantitative manner. In addition, there is an advantage that the circuit configuration or method for executing this can be made simpler than that of the first embodiment.

(Embodiment 4) In the fourth embodiment,
As one electrode 3b of one set of electrodes 3a and 3b,
As shown in FIG. 7A, an example is shown in which the structure of the structure is further simplified by diverting the receiving metal fitting 10 itself made of a conductive material to which the discharge port of the ink container 2 is attached. Alternatively, while the receiving fitting 10 itself may be diverted as one electrode 3b, the position where the other electrode 3a is arranged may be further changed. That is, FIG.
As shown in (B), the electrode 3a may be arranged on the bottom of the bottle (tail end face), which is the end face opposite to the end face where the discharge port of the ink container 2 is located. With such an arrangement, since the receiving metal fitting 10 used as the electrode 3b and the electrode 3a are substantially arranged to face each other, there is also an advantage that a more linear measurement result can be obtained.

As shown in an example of FIG. 7C, one electrode 3b of the pair of electrodes facing each other is made of a conductive material adjacent to the ink container 2 among the components of the printing apparatus. The structure may be further simplified by diverting the constituent member 11.

Also, at least one or both of a pair of electrodes facing each other are attached to the surface of the ink container 2 so that the electrodes 3a and 3b are not on the stencil printing apparatus main body side, but are shown in FIG. As shown, the electrodes 12a and 12b may be arranged on the ink container 2 side. In this case, the electrodes 12a, 1 arranged on the side of the ink container 2
The electrical connection between the 2B and the electric capacity detecting section 4 and the like arranged on the stencil printing apparatus side is made by connecting the contacts 13a and 13b or the probe or the like provided on the stencil printing apparatus side to the electrodes 14a and 14b on the surface of the ink container 2. May be set so as to be in contact with, and the connection may be established by the contact.
More specifically, the surface of the ink container 2 is generally provided with a label or the like for specifying information such as the brand and type of the ink 1 contained in the ink container 2 in many cases. Such a label is formed using a conductive material such as an aluminum thin plate, an aluminum sheet, or a sheet obtained by laminating or vapor-depositing a metal thin film on a resinous film, and forming the label in the first to third embodiments. The electrodes 12a and 3b used to form the electric capacitor Cv as in the above-described embodiment can be used as the electrodes 3a and 3b.
By affixing a and 12b to the surface of the bottle 2 'which is the container body of the ink container 2, it is possible to further simplify the structure of the apparatus including them. In addition, the electrodes 12a, 12b
Is provided, the positional relationship between the electrodes 12a and 12b and the surface of the ink container 2 can be reliably fixed in advance, so that the measurement of the ink remaining amount V can be performed more easily and reliably. The advantage described above can also be obtained.

The physical quantity relating to the electric capacitor Cv having the ink container 2 containing the ink 1 as a dielectric material is not limited to using the capacitance value Cv or the impedance Z of the electric capacitor Cv. It is also possible to use the value of dielectric loss generated due to Cv. That is, the dielectric loss occurring in the AC circuit system including the AC power supply due to the presence of the electric capacitor Cv in the circuit system is measured, and the value V of the remaining ink amount is obtained based on the measured value. It may be.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a main part for measuring the remaining amount of ink in a stencil printing apparatus according to a first embodiment.

FIG. 2 is a diagram showing a schematic configuration of a capacitance detecting unit;

FIG. 3 is a diagram showing an equivalent circuit of an electric capacitor including an ink container 2 containing ink 1 and electrodes.

FIG. 4 is a diagram showing a correspondence relationship (functional relationship) between a capacitance value Cv and an ink remaining amount value V;

FIG. 5 is a diagram illustrating a configuration of a main part for measuring the remaining amount of ink in a stencil printing apparatus according to a second embodiment.

FIG. 6 is a diagram illustrating a configuration of a main part for measuring the remaining amount of ink in a stencil printing apparatus according to a third embodiment.

FIG. 7 is a diagram showing a variation in arrangement of electrodes.

FIG. 8 is a diagram showing an example of a case where electrodes are arranged on the side of an ink container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink 2 Ink container 3a, 3b electrode 4 Electric capacity detection part 5 Ink remaining amount measurement part 6 Display part

Claims (7)

[Claims] 1. A printing apparatus comprising: a printing unit for printing on a printing medium; and an ink container containing ink used for the printing, wherein the printing unit is opposed to the printing medium via the ink container. And at least two electrodes that form an electrical capacitor using at least the ink in the ink container as a dielectric, and at least one of capacitance, dielectric constant, or impedance related to the electrical capacitor. An electric capacity detecting unit for detecting an electric signal corresponding to the value; and an ink remaining amount measuring unit for measuring an ink remaining amount remaining in the ink container in accordance with the detected electric signal. A printing device, characterized in that: 2. The ink remaining amount measuring means prepares in advance information indicating a correspondence between the detected electric signal and the value of the ink remaining amount, and based on the information, 2. The printing apparatus according to claim 1, wherein the value of the remaining amount of ink is obtained in association with the signal. 3. The printing apparatus according to claim 2, wherein the ink container has an ejection port for ejecting ink, and the printing apparatus includes a receiving member made of a conductive material to which the ejection port is attached. The printing apparatus according to claim 1, wherein the printing apparatus is used as one of the printing apparatuses. 4. The printing apparatus according to claim 1, wherein a component made of a conductive material adjacent to the ink container is used as one of the electrodes. The printing device according to claim 1. 5. A structure in which at least one of the opposed electrodes is divided into two or more small electrodes, and the electric signal is detected separately for each of the divided small electrodes. The method according to claim 1, wherein the remaining amount of the ink in the ink container is measured stepwise at least for each of the small electrodes based on the electric signal for each of the small electrodes. Printing equipment. 6. A printing means for printing on a printing medium, and an ink container containing ink used for the printing, and a pair of the ink containers facing each other via the ink container. At least the ink in the ink container is used as a dielectric to form an electrical capacitor.
A plurality of electrodes, an electric capacitance detecting means for detecting an electric signal corresponding to at least one of capacitance, a dielectric constant, and an impedance of the electric capacitor; and an electric capacitance detecting means corresponding to the detected electric signal. And a remaining ink amount measuring means for measuring the remaining amount of ink remaining in the ink container, wherein at least one of the electrodes is provided on a surface of the ink container. An ink container, characterized in that: 7. The printing apparatus according to claim 1, wherein stencil printing is performed on the printing medium.