JPH08290583A - Ink residue detector - Google Patents

Abstract

PURPOSE: To provide an ink residue detector which can detect the residue of ink without complicating the structure of an ink cartridge. CONSTITUTION: When a voltage is applied to a head 4, charge is fed to the electrode 2 of the non-contact part with ink 6 via a voltage detecting resistor 5 by electrostatic induction with the ink 6 as dielectric material. Thus, a voltage is generated at an output detecting point 7. When the height of the liquid level of the ink 6 is varied, the opposed area between the ink 6 of the dielectric material and the electrode 2 is changed and the voltage generated at the point 7 is altered. Thus, the output responsive to the residue of the ink 6 can be obtained from the point 7. Accordingly, since the electrode 2 can be disposed at the non-contact part with the ink 6, the residue of the ink 6 can be detected without complicating the structure of the cartridge 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink remaining amount detecting device in an ink jet printer.

[0002]

2. Description of the Related Art In an ink jet printer, ink in an ink cartridge is supplied to a recording head, and ink is discharged from a discharge port of the recording head to record a character or an image on a recording medium, but the ink is not supplied to the discharge port. If recording is attempted to continue in the state of running out of ink, there are problems that the life of the head is shortened and print quality is deteriorated.

Therefore, conventionally, as a device for detecting the remaining amount of ink, a pair of electrodes are provided in the ink cartridge so as to make contact with the ink by utilizing the conductivity of the ink, and the remaining amount of ink is supplied by energizing between the pair of electrodes. An ink remaining amount detecting device for detecting the ink has been used.

[0004]

However, the above-mentioned conventional ink remaining amount detecting device has a problem that the structure of the ink cartridge becomes complicated because it is necessary to provide an electrode inside the ink cartridge so as to contact with the ink. Was.

The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an ink remaining amount detecting device which can detect the remaining amount of ink without complicating the structure of the ink cartridge. .

[0006]

In order to achieve the above-mentioned object, the present invention uses an ink as a dielectric and an electrostatic charge when a voltage is applied to a head for discharging a current by causing an electric current to flow through the conductive ink to heat the ink itself. A detector is provided on the side surface of the ink cartridge, which detects the voltage generated on the side surface of the ink cartridge by the induction, the electrode not contacting the ink.

[0007]

With the above arrangement, the present invention can detect the amount of ink remaining in the ink cartridge based on the detection result of the detection means.

[0008]

【Example】

(Embodiment 1) Hereinafter, the present invention will be specifically described with reference to the drawings. FIG. 1 is a configuration diagram of an ink remaining amount detecting device according to a first embodiment of the present invention. Reference numeral 1 is an ink cartridge for accommodating a conductive ink 6, and reference numeral 2 is an electrode provided in a non-contact manner with the ink 6, which is arranged long in the decreasing direction of the ink 6 and is grounded through a voltage detection resistor 5. Also,
The ink 6 in the ink cartridge 1 is supplied to the head 4 through the ink supply path 3 and is ejected. Reference numeral 7 is an output detection point.

The operation of the ink remaining amount detecting device configured as described above will be described below. In an energization type ink jet printer in which a current is applied to the ink 6 to directly generate heat and eject the ink 6, a voltage of several V to several tens of V is applied to the head 4 when ejecting the ink 6.
When the potential of the head 4 rises at this time, electric charges having a polarity opposite to the potential of the head 4 flow into the electrode 2 through the voltage detection resistor 5 due to electrostatic induction. As a result, a voltage is generated at the output detection point 7. The ink 6 in the ink cartridge 1 then acts as a dielectric between the head 4 and the electrode 2. When the liquid surface height of the ink 6 in the ink cartridge 1 changes, the ink 6
The area where the electrodes 2 face each other changes, and the voltage generated at the output detection point 7 also changes. Therefore, an output according to the remaining amount of the ink 6 can be obtained from the output detection point 7.

(Second Embodiment) A second embodiment of the present invention will be described below. FIG. 2 is a configuration diagram of an ink remaining amount detecting device according to the second embodiment of the present invention. Reference numerals 8 and 11 denote electrodes, and a plurality of electrodes are arranged with a height difference in the decreasing direction of the ink 6. Reference numeral 9 is a voltage detection resistor, which is connected to each of the electrodes 8 and 11. 10 and 12 are output detection points. The other structure is the same as that of the first embodiment.

The operation of the ink remaining amount detecting device constructed as described above will be described below. When a voltage is applied to the head 4 similarly to the first embodiment, when the potential of the head 4 rises on the electrode 8 below the liquid surface of the ink 6, a charge of the opposite polarity to the head 4 is correspondingly generated. Voltage detection resistor 9
A voltage is generated at the output detection point 12 flowing in through. On the other hand, even if a voltage is applied to the head 4 at the electrode 11 above the liquid surface of the ink 6, there is no ink 6 that serves as a dielectric between the head 4 and the electrode 11, so that no charge flows into the electrode 11. No voltage is generated at the output detection point 10. From the above, the electrode 8 having an output and the electrode 11 having no output are separated depending on the liquid surface of the ink 6, and the remaining amount of the ink 6 can be output by a binary signal.

As described above, in the ink remaining amount detecting device of the present invention, since the electrodes 2, 8 and 11 are arranged in the portions which are not in contact with the ink 6, the structure of the ink cartridge 1 does not become complicated, and the ink 6 is stored. The remaining amount can be detected.

[0013]

As described above, the ink remaining amount detecting apparatus of the present invention uses the ink as a dielectric and electrostatically when the voltage is applied to the head which discharges the ink by applying a current to the conductive ink to heat the ink itself. By providing the detection means for detecting the voltage generated on the side surface of the ink cartridge, which is provided in contact with the ink, by the induction, it is possible to detect the remaining amount of ink in the ink cartridge by the detection result of the detection means. In addition, since the electrodes are arranged at the portions that are not in contact with the ink, it is possible to detect the remaining amount of ink without complicating the structure of the ink cartridge.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an ink remaining amount detection device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of an ink remaining amount detecting device according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Ink Cartridge 2 Electrode 3 Ink Supply Channel 4 Head 5 Voltage Detection Resistor 6 Ink 7 Output Detection Point 8 Electrode 9 Voltage Detection Resistor 10 Output Detection Point 11 Electrode 12 Output Detection Point

Claims (2)

[Claims] 1. A head for discharging an ink by causing an electric current to flow through the conductive ink to heat the ink itself, an ink cartridge containing the ink to be supplied to the head, and a side surface of the ink cartridge provided in a non-contact manner with the ink. And a detection unit that detects a voltage generated in the electrode by electrostatic induction using ink as a dielectric when the voltage is applied to the head. 2. The ink remaining amount detecting device according to claim 1, wherein a plurality of the electrodes are arranged with a height difference in the ink decreasing direction.