JP2931079B2 - Ink detector for recording device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an ink detection device in a printing apparatus, and more particularly, to an apparatus for detecting remaining ink in an ink tank in a printing apparatus.

Prior art Ink supply methods in inkjet recording devices
There are a pressurized supply system and a hydrostatic pressure system. In the hydrostatic pressure method, the inside of an ink tank is maintained at an atmospheric pressure, and the recording ink is fed to the recording head via an ink supply pipe by the hydrostatic pressure due to the atmospheric pressure and the capillary force of the recording head unit. However, the problem with this hydrostatic pressure method is how to detect that the ink in the ink tank has been consumed and the remaining amount has become small. This problem is the same in a pressurized supply system using a pump means or the like.

Conventionally, for example, the following various methods have been known as such ink remaining amount detecting means, but all of them have practical problems.

(1) A method of counting a drive signal for ink ejection.

In this method, the memory for storing the amount of ink consumption detected for repeated use needs to be non-volatile, and the device becomes complicated and expensive.

In addition, since the size of each ink droplet slightly varies depending on various conditions, when the number of ink droplets is counted, the accumulated error of the consumed ink amount increases, and the remaining ink amount becomes inaccurate.

(2) A method of detecting a shortage of the ink amount from a change in the electric resistance value of the ink existing between two opposed electrodes fixed to the bottom of the ink storage container (Japanese Patent Laid-Open No. 52-130330).

In this method, a large variation occurs in the detection amount due to the fluctuation of the ink surface in the ink tank, and the stable remaining amount cannot be detected, and thus the reliability is lacking.

(3) A method of detecting the remaining amount from the ink level in the ink storage container.

In this method, a photocoupler comprising a light-emitting portion and a light-receiving portion is used as a liquid level detection sensor (Japanese Patent Laid-Open No. 54434/1979), or a floating member on the ink level and a magnetic detector are used. Method using a magnetic sensor (Showa 54
Although these methods are known, these methods cannot be used for a closed ink storage container described below that does not have a liquid surface that moves in contact with air.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a reliable and simple structure ink detecting means as an ink remaining amount detecting means in an ink jet recording apparatus. is there.

In order to achieve the above object, the present invention provides an ink detection device for a recording device for detecting ink remaining in an ink tank of a recording device, wherein a porous body having continuous pores is arranged in the ink tank. A body portion, a hollow portion not provided with the porous body portion, and a plurality of electrodes for detecting an ink remaining amount in the hollow portion having an ink ejection port adjacent to the porous body portion. It is characterized by having been done. Hereinafter, a description will be given based on examples of the present invention.

FIG. 1 is a plan view for explaining one embodiment of an ink detecting device according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is another embodiment of the present invention. In the figure, 1 is an ink tank, 2 is a porous body having continuous pores, 3 is an electrode, 4 is an ink outlet tube, 5 is an ink supply port, 6 is an air communication hole, Reference numeral 7 denotes a cavity.

In the embodiment shown in FIGS. 1 and 2, a porous body 2 is provided along a peripheral wall in an ink tank 1;
The center of the ink tank 1 is a cavity 7. At the bottom of the cavity 7, two electrodes 3, 3 are arranged at a predetermined interval, and at the bottom of the porous body 2, an outlet pipe 4 for feeding ink is provided. At the time of ink discharge (at the time of printing)
Print head (not shown) via an ink outlet pipe 4
Is supplied, the ink in the cavity 7 is consumed first, and after the ink in the cavity 7 is exhausted, the ink impregnated in the porous body 2 is consumed. In the case of conductive ink, if ink remains in the cavity 7, the ink makes the two electrodes 3, 3 electrically conductive, and when the ink runs out, the electrodes 3, 3 become non-conductive. State. As described above, in the present invention, the signal of the non-conduction between the two electrodes 3, 3 indicates an out-of-ink warning.

At the time of printing, the ink is discharged from the cavity 7, and the two electrodes 3, 3 become non-conductive, and even if the display of the ink shortage is displayed, the ink remains in the porous body 2, Printing is possible. Therefore, if the ink is replenished into the ink tank 1 during this period, printing will not be disabled due to lack of ink.

In addition, similarly, when using a non-conductive ink, 2
A change in the dielectric constant between the electrodes 3, 3 warns that ink has run out. The ink tank may be mounted on the print head carriage or may be installed outside the print head carriage.

FIG. 2 shows an example in which the ink filling amount is increased when the tank volume is the same as that of the ink tank 1 in the above-described embodiment. The porous body portion in the ink tank 1 is different from the first embodiment. So that the ratio of
A porous body 2 is provided in an ink tank 1, and an ink outlet pipe 4 is provided at the bottom of the porous body 2.

Advantages As is clear from the above description, according to the present invention, it is possible to easily and accurately detect the remaining amount of ink in the ink tank.

[Brief description of the drawings]

FIG. 1 is a plan view for explaining one embodiment of an ink detecting device according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is another embodiment of the present invention. It is a figure for explaining an example. 1 ... ink tank, 2 ... porous body, 3 ... electrodes, 4
... Ink outlet pipe, 5 ... Ink supply port, 6 ... Atmosphere communication hole, 7 ... Cavity.

Claims (1)

(57) [Claims] An ink detecting apparatus for a recording apparatus for detecting ink remaining in an ink tank of a recording apparatus, wherein a porous body having continuous pores is arranged in the ink tank; A cavity in which the body is not disposed, and an ink discharge port in the vicinity of the porous body, and a plurality of electrodes for detecting remaining ink are arranged in the cavity. Ink detector for recording device.