JPH0117465B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the remaining amount of ink in an ink storage container, and more specifically, the present invention relates to a device for detecting the remaining amount of ink in an ink storage container, and more specifically, a device for detecting the remaining amount of ink by changing the resistance value between electrodes provided in the ink storage container. The present invention relates to the structure of the electrodes of the device used.

Various devices have been devised so far to detect the amount of ink remaining by changing the resistance value between electrodes provided in the ink storage container.
No., JP-A-54-10735, etc. These devices operate the display device or stop the recording device when the resistance value between the electrodes reaches a preset value, but the electrical resistance value of the ink is temperature dependent. To counteract this, complicated circuits such as temperature compensation circuits are used. In addition, the electrical resistance changes depending on the concentration of the ink, so three electrodes are provided to eliminate this effect, but this has the disadvantage of complicating the circuit configuration and increasing cost. .

Furthermore, as shown in Figures 1 and 2, in the case of aqueous ink whose main components are water, wetting agent, and dye, the resistance value is several tens of K when there is ink between the electrodes 4a and 4b.
It shows a value of Ω to several hundred KΩ. As the ink is consumed and the amount of ink decreases, and the ink disappears between the electrodes 4a and 4b, there should be an insulating state between the electrodes 4a and 4b. However, due to the viscosity and surface tension of the ink itself, when conventional electrodes are used, even if the ink level drops to the ink outlet, the corner of the ink storage container or the wall between the electrode 4a and the ink storage container Ink accumulates in the corners of the electrodes 4a, 4.
Although there is an increase in the resistance value between electrodes 4a and 4b, it becomes conductive, and in order to detect the remaining amount, it is necessary to compare the preset resistance value with the resistance value between electrodes 4a and 4b. It required a complex circuit.

The present invention has been made to eliminate these drawbacks, and its purpose is to provide a remaining ink amount detection device that has a simple structure, is inexpensive, and has high detection accuracy.

The gist of the present invention is to provide an ink remaining amount detection device for detecting the remaining amount of ink in an ink storage container, comprising: an ink storage container in which a protrusion is formed at the bottom of a container filled with ink; a cradle for mounting and supporting the ink storage container and having a fitting part that fits with the protrusion; a pedestal fixed to the pedestal and protruding toward the ink reservoir; and an ink retrieving hollow needle whose tip breaks through the rubber sealing material and protrudes into the ink storage container when the ink storage container is mounted and supported in the fitting part, and a hollow needle for taking out the ink that is fixed to the holder and whose tip protrudes into the ink storage container. a pair of electrode members that protrude toward the storage container and break through the rubber sealing material and protrude into the ink storage container when the ink storage container is attached to the fitting portion; The remaining ink amount detecting device is characterized in that the electrode member is coated with an insulator except for the tip portion protruding into the ink storage container, and the presence or absence of the ink in the ink storage container is detected by the tip portion. .

An embodiment of the present invention will be described below with reference to FIGS. 3 to 7.

The present invention has been made to eliminate these drawbacks, and an object of the present invention is to provide an inexpensive ink remaining amount detection device with a simple structure.

FIG. 3 is an enlarged view showing one embodiment of the electrode of the present invention.

As shown in the figure, the electrodes 4a and 4b are covered with an insulator 6 except for the tips of the electrodes 4a and 4b, which protrude into the ink storage container. It is desirable that the insulator 6 covers the electrode in a tapered shape so that no corners are formed as much as possible.
When the amount of ink decreases and the ink level becomes lower than the electrodes 4a and 4b, the electrodes 4a and 4b are covered with an insulator except for their tips, so the electrodes 4a and 4b are insulated, which makes the circuit simple. The presence or absence of ink can be detected. In addition, since the boundary between the insulator and the tip of the electrode is tapered so that no corner is formed, ink does not accumulate at the corner, and the ink liquid level at the tip of the electrodes 4a, 4b is lower than that of the electrodes 4a, 4b.
As soon as it falls below b, it becomes an insulator.

In order to reliably eliminate the influence of the surface tension of the ink, the rise in the liquid level due to the surface tension of the ink is approximately 1 to 2 mm, so it is desirable that the portion of the electrode protrude into the storage container be 3 mm or more. It's better.

Figure 4 shows an example of a circuit for detecting the remaining amount of ink, where 21 and 22 are inverters, and R is 1MΩ.
It is connected to a positive potential with a certain resistance, and B,
C is connected to the electrodes 4a and 4b.

Figures 5a and 5b show voltage waveforms at terminals A and D. When a pulse waveform like a is applied to terminal A, when ink exists between electrodes 4a and 4b, terminal D is applied to voltage waveform b. A waveform like this is obtained, and when the ink runs out, the waveform at terminal D remains at the LOW level.

FIG. 6 is a sectional view of a cartridge type ink storage container showing another embodiment of the present invention, and FIG. 7 is an enlarged view of the electrode portion of FIG. 6.

11 is an ink storage container, 12 is ink, 13 is a hollow needle for taking out ink, 14a and 14b are electrodes, 1
5 is an air vent hole, 16 is a rubber seal, and 17 is a pedestal 18 which is an insulating material.

Hollow needle 13 for taking out ink, electrodes 14a, 14b
are fixed to the cradle 17, and when the cartridge type ink storage container 11 is set on the cradle 17, the hollow needle 13 for taking out the ink, the electrode 14a,
14b pierces the rubber seal 16. Electrode 14
A and 14b are covered with an insulator 18 except for the tips, as shown in FIG.

As the ink decreases, the ink liquid level reaches the electrodes 14a, 1.
4b, the electrodes 14a and 14b become insulated and the remaining amount can be detected in the same way as in the previous embodiment.

In this embodiment, since the electrodes are provided on the pedestal 17, the structure of the ink reservoir is simplified and the cost is reduced.

As described above, according to the present invention, the part of the electrode that protrudes into the ink storage container is coated with an insulating material except for the tip, so that when the ink liquid level falls below the electrode, the electrode becomes insulated, which can be easily It is now possible to detect the remaining amount of ink using the circuit. Furthermore, since the structure is simple with only two electrodes, the cost is low, and its effects are very large.

Furthermore, a hollow needle for taking out ink and a pair of electrode members for detecting the presence or absence of ink in the ink storage container are fixed to the cradle that supports the attachment of the ink storage container, so that the ink in the ink storage container runs out. If necessary, the ink storage container can be easily removed from the cradle and replaced with a new one. Furthermore, since the hollow needle for taking out the ink and the pair of electrodes are fixed to the pedestal, there is no need to set them again in the rubber sealing material of the ink storage container each time they are replaced. Furthermore, since the ink storage container is attached to and supported by a fitting part formed on the pedestal, the amount by which the ink retrieval hollow needle and the pair of electrode members, which are fixed to the pedestal, protrude into the ink storage container is reduced. is always stable;
It becomes possible to stably detect the remaining amount of ink.

In addition, in the example, an example was explained in which the ink storage container was made of a hard material and provided with an air vent hole.
This is also possible even if it is made of a soft rubber-like material and has no air vent holes.

Further, the detection circuit described in the embodiment is just one example, and in short, it is sufficient if it can detect whether it is a conductive state or an insulated state, and various methods are possible, and the detection circuit is not limited to this embodiment.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing one embodiment of the remaining ink amount detection device, Fig. 2 is an enlarged view of a conventional electrode portion, and Fig. 3
The figure is an enlarged view showing one embodiment of the electrode of the present invention. 1 is an ink storage container, 2 is ink, 3 is an ink outlet, 4a and 4b are electrodes, and 6 is an insulator. FIG. 4 is a diagram showing an embodiment of the remaining ink amount detection circuit, and FIGS. 5a and 5b are diagrams showing voltage waveforms. FIG. 6 is a sectional view of a cartridge type ink storage container showing another embodiment of the present invention, and FIG. 7 is an enlarged view of the electrode portion of FIG. 6. 11 is an ink storage container, 12 is ink, 13 is a hollow needle for taking out ink, 14a and 14b are electrodes, 1
6 is a rubber seal, 17 is a pedestal, and 18 is an insulator.

Claims (1)

[Scope of Claims] 1. An ink remaining amount detection device for detecting the remaining amount of ink in an ink storage container, comprising: an ink storage container in which a protrusion is formed at the bottom of the container filled with ink; and the protrusion. a rubber sealing material that shields a lower surface of the ink storage container; a pedestal having a fitting portion that fits with the protrusion portion and for mounting and supporting the ink storage container; and a pedestal fixed to the pedestal and protruding toward the ink storage container. and an ink retrieving hollow needle whose tip pierces the rubber sealing material and projects into the ink storage container when the ink storage device is mounted and supported in the fitting portion; a pair of electrode members that protrude toward the container and break through the rubber sealing material and protrude into the ink storage container when the ink storage container is attached to the fitting portion; An ink remaining amount detecting device characterized in that the member is coated with an insulating material except for a tip portion protruding into the ink storage container, and the presence or absence of the ink in the ink storage container is detected by the tip portion.