JPS59190856A - Detector for residual ink - Google Patents

Abstract

PURPOSE:To detect residual ink with a high accuracy by a durable and simple structure in which the hollow needle of a residual ink detector in an ink jet printer is made up of a double electric conductive layer interleaved with an electric insulator layer. CONSTITUTION:A metal hollow needle 19 is inserted through an insulator 21 into a metal hollow needle 20, and its outer end is connected with a supply tube 23 for a printer. The other end portion of three layers is slantly cut off and shaped into a needle form which is projected into the pipe 5 of an ink housing bag 1. The hollow needles 19 and 20 are buried in an insulating holder 24, conductors 26 and 27 connected to the hollow needles 19 and 20 through holes 24a and 24b are taken out and entered into the residual ink detector 25, and the detected results are notified by a notifier 28. Residual ink can thus be detected with a high accuracy at low cost by a durable and simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a residual ink detection device, and particularly to a residual ink detection device for detecting residual ink in an ink storage container used in an inkjet printer.

BACKGROUND ART Traditionally, inkjet printers record information such as letters and pictures as dots by colliding liquid ink with a sheet of paper according to the information to be recorded.

Therefore, the ink must be stored as a liquid, like gasoline in a car.Furthermore, when the ink is ejected, the ink scatters and contaminates the surrounding area. Must be stored in a container. In addition, since the ink must be stored so that its physical properties, such as surface tension, viscosity, and PI, are kept at constant values, it is necessary to prevent evaporation and deterioration of the constituent components of the ink as much as possible. In addition, in the case of inkjet printers that eject ink by pressurizing the ink and selectively charging and deflecting the droplets to record, the ink is ejected by applying voltage only when recording is necessary. It is necessary to keep the ink level constant and at the same pressure as the atmosphere.

On the other hand, when the amount of ink remaining in the ink container becomes low, it becomes necessary to replenish the ink or replace the ink container.

This is the first ink storage container that satisfies these conditions.
A structure as illustrated in FIG. 2 is used. That is, as shown in FIG. 1, ink 2 is stored in a storage bag 1 having a three-layer structure, and the entire ink storage bag 1 is stored in an ink cassette 4 provided with a ventilation hole 3.
The structure is such that the ink 2 is led out to the outside through a lead-out pipe 5 and a rubber stopper 6 arranged inside. Specifically, the ink 2 is taken out by connecting the hollow oblique 7 to the extraction vibe 5 that is led to the rubber stopper 6. This ink storage bag 1 has aluminum thin films 9 and 5 with a thickness of approximately 10 μm to prevent deterioration due to, for example, as shown in FIG.
It consists of an inner main bag 10 made of a thin polyethylene film with a thickness of 0 to 70 μm. (3) In the case of an ink storage container constructed in this way, ink is replenished by replacing the entire case or cassette. The old cassette will be thrown away. The ink storage bag 1 is a flat bag, and the ink level changes by about 10 degrees at most from when it is full to when it is empty, and is configured to minimize changes in pressure.

When an ink storage container configured in this way is connected to an inkjet printer for recording, it is known that when the remaining ink becomes low, the print density does not gradually become lighter and printing suddenly becomes impossible. . This unprintable phenomenon also occurs when the device is subjected to shocks, etc.
It is impossible to determine whether printing is not possible due to impact or printing is not possible due to a low amount of ink remaining. Therefore, it is necessary to accurately inform the user of the remaining amount of ink in order to replenish ink, replace the ink storage bag, or determine whether printing is impossible due to impact.

(4) Conventionally, a mechanism as shown in FIG. 3 has been generally used to detect the amount of liquid remaining in a liquid storage container. That is, in the mechanism shown in FIG. 3(a), a float 12 with a built-in magnet is suspended in a side channel 13 of a liquid container 11, and
A reed switch 14 is arranged opposite to.

When the liquid 15 in the liquid container 11 becomes low, the float 12 in the side channel 13 is lowered according to the level of the liquid 15, and the reed switch 14 is operated to detect the remaining amount of ink. Further, in the mechanism shown in FIG. 3(1)), the light emitting means 16e and the light receiving means 1 are used instead of the reed switch 14.
7 is used to detect the remaining amount of liquid, and when the amount of liquid such as opaque ink decreases to below a predetermined level, the light receiving means 17 receives light from the light emitting means 16 to detect the remaining amount of liquid. This is the method of trying to detect it.

In the mechanism shown in FIG. 3(c), two conductors 18 are inserted into the liquid 15, and these are used as electrodes to connect the liquid 15.
It detects the change in resistance due to a decrease in the amount of fuel remaining, and takes advantage of the fact that the resistance value suddenly increases when the remaining amount is low.

However, such a conventional liquid remaining amount detection method cannot be used to detect the remaining amount of ink contained in a flat type ink storage container as shown in FIG. This is because this type of ink storage container is designed to minimize changes in the liquid level in order to keep the ink pressure constant. In addition, even with the mechanism shown in Figure 3(c), even if the ink is low and completely gone, there is a risk that the resistance will decrease due to the ink stuck inside the ink storage bag, making it difficult to accurately determine the amount of ink remaining. Unable to detect.

OBJECTIVES: Therefore, the present invention solves these conventional drawbacks, and provides an ink remaining amount detection device that can inexpensively and reliably detect the amount of ink remaining in an ink storage container. The purpose is to

EXAMPLES Hereinafter, the present invention will be explained in detail based on examples shown in the drawings.

FIG. 4 and FIG. 5 illustrate one embodiment of the present invention.
To make the explanation easier to understand, a hollow needle provided on the main body side of a printer (not shown) is shown piercing an ink cassette.

In FIG. 4, the same parts as in FIG. 1 are denoted by the same reference numerals, and their explanation will be omitted.

The ink storage bag 1 built into the ink cassette 4 is provided with a lead-out pipe 5 at its end for leading the ink 2 to the printer main body side, and this pipe 5 is used to prevent ink from flowing out. It is held by a rubber stopper 6 fitted into the opening 1 of the ink cassette 4.

On the other hand, a metal hollow needle 19 is inserted into a metal hollow needle 20 having a larger inner diameter with an insulating member 21 interposed therebetween and fixed integrally therewith. Hollow needle 19 is hollow needle 20
The outer end of the hollow needle 19 has a pipe 5 leading out from the ink storage bag 1.
An ink supply tube 23 for guiding the ink 2 drawn out through the hollow needle 1920 to the printer is connected (7). In addition, the metal hollow needles 19 and 20 are mounted on an insulating holding base 2.
4, and holes 248, 241) are bored in the j-joint 24 of the scale. The metal parts of each hollow needle 19, 20 are electrically connected to the residual ink detecting section 25 by conductive wires 26, 27 through these holes. Reference numeral 28 denotes a notification section that indicates the detection result detected by the detection section, and is composed of an optical display, an audible alarm, or the like.

Next, the operation of the present invention configured as follows will be explained.

Figure 4 shows an ink cassette with a built-in ink storage bag as described above, which pierces the rubber stopper 6 with the hollow needle 19, 20 supported by the holding stand 24 on the printer body side, and ink is supplied to the printer body. This indicates the status of supply to the
Indicates that there is a sufficient amount of ink remaining.

In this state, the inner surface of the metal hollow needle 19 and the outer surface of the hollow needle 20 are detected by the conductive ink 2 filling the hollow needle 19 and the outlet pipe 5 through the conductive wires 26 and 27. An electrically conductive circuit is formed between (8) and the ink residual detecting section 25, so that the ink residual detecting section 25 detects the residual ink and sends a signal to that effect to the notifying section 28 to notify the user of the ink remaining. Make the remaining known.

On the other hand, FIG. 5 shows a state when the ink 2 contained in the ink storage bag 1 is used up and there is little left. In this state, the ink 2 filled in the hollow needle 19 and the outlet pipe 5 shown in FIG. The conduction state of is cut off, and the ink remaining detection section detects this non-conduction state and sends a signal to that effect to the notification section 2θ to notify the user that ink is almost exhausted.

Effects As is clear from the above explanation, the present invention uses a three-layer structure in which an insulating member is sandwiched between a hollow needle for guiding ink from an ink cassette to the printer body, and the outer and inner surfaces of the hollow needle are made of metal. By adopting this method, two states of electrical conduction and non-continuity are created between the ink residual detection section and the residual ink depending on whether or not there is residual ink, and the residual ink is thereby detected. It is possible to provide an ink residual detection device with a simple structure, low cost, high durability, and high accuracy without using moving parts lacking in precision or expensive light emitting and light receiving elements, which are seen in residual ink detectors.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an ink cassette containing an ink storage bag in which the device of the present invention is used, Fig. 2 is a sectional view showing the structure of the ink storage bag shown in Fig. 1, and Figs. 3(a) to (C) are A schematic explanatory diagram showing a conventional residual ink detection device, FIG. 4 is a sectional view showing the structure of the residual ink detection device according to the present invention when ink remains, and FIG. 5 is a diagram showing the structure of the residual ink detection device according to the present invention when ink runs out. It is a sectional view showing a state. 1... Ink storage bag 2... Ink 5... Output pipe 19.20... Hollow needle red 21... Insulating member 24... Support stand 25...
Remaining ink detection section 28...notification section.

Claims (2)

[Claims] (1) In an ink residual detection device that detects residual ink in an ink cartridge supplied to an inkjet recording device via a hollow needle, the hollow needle is composed of two electrically conductive layers sandwiching an electrically insulating layer. An ink remaining detection device is characterized in that ink remaining is detected by detecting a state of conduction between two of the conductive layers. (2) The residual ink detection device according to claim 1, wherein the detection is performed by notifying the detection result optically or acoustically.