JPH0360670B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an inkjet printer equipped with means for detecting the amount of ink remaining in an ink container that supplies ink to a recording head that ejects ink.

Conventionally, ink jet printers record information such as letters and pictures as dots by colliding liquid ink with the paper in the form of droplets according to the information to be recorded.

Therefore, ink must be stored as a liquid, like gasoline in automobiles, and furthermore, if the ink scatters when ejected, it will stain the surrounding area, so care should be taken to prevent ink from leaking due to vibrations or shocks. Must be stored in an ink container. Furthermore, since the ink must be stored so that its physical properties, such as surface tension, viscosity, and pH, are constant, it is necessary to prevent evaporation and deterioration of the ink components as much as possible. In addition, in the case of an ink jet printer, the ink is ejected by applying a voltage only when recording is necessary, instead of ejecting the ink by pressurizing it and selectively charging and deflecting the droplets to record. teeth,
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.

As an ink storage container that satisfies these conditions, a structure as shown in FIGS. 1 and 2 is known. That is, 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 the arranged lead-out pipe 5 and rubber stopper 6. Specifically, the ink 2 is taken out by connecting the insertion needle 7 to the outlet pipe 5 led to the rubber stopper 6. For example, as shown in FIG. 2, this ink storage bag 1 has a nylon outer protective plastic thin film 8 with a thickness of 5 to 10 μm, and an aluminum thin film 9 with a thickness of about 10 μm to prevent ink evaporation and deterioration due to ultraviolet rays. and a flexible ink bag 10 made of a thin polyethylene film with a thickness of 50 to 70 μm.

In the case of an ink storage container constructed in this manner, ink is replenished by replacing the entire case or cassette, and the old cassette is discarded. The ink storage bag 1 is a flat bag, and the ink level changes by a maximum of about 10 mm from when it is full to when it is empty, and is configured to minimize changes in pressure.

When connecting an ink storage container configured in this way to an inkjet printer for recording,
It is known that when the remaining amount of ink becomes low, printing suddenly becomes impossible without the print density gradually becoming lighter. Such a printing failure phenomenon also occurs when a shock or the like is applied to the device, and it is impossible to determine whether the printing failure is due to the impact or the printing failure is 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 the ink, replace the ink storage bag, or determine whether printing is impossible due to impact.

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. 3A, a float 12 having a built-in magnet in a side passage 13 is suspended in a liquid container 11, and a reed switch 14 is disposed opposite the side passage 13.

When the liquid 15 in the liquid container 11 becomes low, the float 12 in the side passage 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. Also, Figure 1b
The mechanism shown in Figure 1 detects the remaining amount of liquid using a light emitting means 16 and a light receiving means 17 instead of the reed switch 14. When the amount of liquid such as opaque ink decreases to below a predetermined level, light is detected. This is a method in which the means 17 receives light from the light emitting means 16 to detect the remaining amount of liquid.

In addition, in the mechanism shown in FIG. 3c, two conductors 18 are inserted into the liquid 15, and these are used as electrodes to detect resistance changes due to a decrease in the liquid 15. When the remaining amount becomes low, the resistance value suddenly changes. It takes advantage of the fact that the water rises.

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. Furthermore, even with the mechanism shown in Figure 3c, even if the ink is low and completely gone, there is a risk that the resistance will drop due to ink adhering to the inside of the ink storage bag, so it is difficult to accurately detect the remaining amount of ink. I can't.

Therefore, the present invention aims to solve these conventional drawbacks, and provides an inkjet equipped with an ink remaining amount detection means that can inexpensively and reliably detect the amount of ink remaining in an ink storage container. The purpose is to provide printers.

The inventor of the present invention conducted extensive research to achieve the above object, and as a result, the remaining amount of ink was determined by using a flexible ink bag and utilizing the displacement caused by the collapse of the ink bag as the ink was consumed. We have found that the remaining amount of ink can be reliably detected by detecting the amount of ink remaining.

The present invention has been proposed based on the above-mentioned findings, and includes a loading section for an ink container that is removably attached to an inkjet printer and stores ink to be supplied to a recording head, and an ink container in the ink container. In the inkjet printer, the inkjet printer has a detection means for detecting the consumption of the ink, wherein the ink container houses a flexible ink bag that stores ink and is displaced according to the consumption of the ink. A central region of the upper surface of the ink bag includes at least a plate member that is displaced together with the ink bag, and a displacement member that contacts the plate member and is displaced in accordance with the displacement of the plate member. The present invention is characterized in that the remaining amount of ink is detected by detecting the displacement state with the detection means.

That is, the present invention includes a plate-like member on the upper surface of the ink bag, which has flexibility as a whole, and a displacement member that is brought into contact with the plate-like member displaces along the direction of gravity as ink is consumed. The structure is such that the displacement reflects the state, and this is detected by the detection means.

In this way, since the ink bag is entirely flexible, the ink consumption efficiency is good. In addition, since the displacement of the flexible ink bag along with gravity is reflected by the plate-shaped member provided in the center area of the top surface of the ink bag, the natural displacement state is effectively utilized without causing the ink bag to collapse to one side. The ink bag can be collapsed almost uniformly, and the accuracy of detecting the remaining amount of ink can be improved.

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

FIG. 4 shows an embodiment of the present invention, in which the same parts as in FIG. 1 are designated by the same reference numerals and their explanation will be omitted. In this embodiment, an ink storage bag 1 made of a flexible material is placed inside an ink cassette 4, which is an ink container loaded into an ink container loading section of an inkjet printer.
A flat plate 22 made of a flat, hard-to-deform plate-like member is disposed on the top of the ink storage bag 1 so as to be in contact with at least the central region of the upper surface of the ink storage bag 1. This flat plate 22
An opening 4a is provided at the top of the ink cassette 4 at the center of the ink cassette 4.
is provided, and the arm piece 20 is arranged so as to contact the part of the flat plate 22 facing this opening 4a. This arm piece 20 is configured to be able to rotate around a shaft 21, and is a displacement member that is displaced in accordance with the displacement of the flat plate 22, and a permanent magnet piece 19 is disposed in a part of the arm piece 20. The flat plate 22 moves up and down as the amount of remaining ink changes, and the arm piece 20 rotates about the shaft 21 accordingly. In this case, a reed switch 23 is placed in the movement trajectory of the permanent magnet piece 19. This reed switch 23 is connected in series with a power source 24 along with a resistor 26 and a light emitting diode 25.

In such a configuration, the shape of the ink storage bag 1 changes according to the amount of ink consumed, and accordingly, the entire flat plate 22 disposed above the bag 1 freely descends. Therefore, as the ink in the ink storage bag 1 decreases, the flat plate 22 also goes down, and at the same time the arm piece 20 moves to the lower position as shown by the dotted line in FIG. As a result, arm piece 2
The permanent magnet piece 19 fixed at 0 also moves to the position indicated by 19', and the adjacent reed switch 2
Turn on 3. Therefore, a driving voltage is applied to the light emitting diode 25 connected in series with the light emitting diode 25, and the light emitting diode 25 emits light, allowing the user to detect that the remaining amount of ink is getting low.

In the above embodiment, instead of using the reed switch 23 as the switching means, if a light emitting diode and a phototransistor are combined to detect the movement of the arm piece, the arm piece can be made lighter.

Furthermore, as shown in FIG. 5, it is also possible to display the amount of ink by observing the deflection of the pointer in the rotational directions E to F around the axis 21 of the arm piece 20 without using a light emitting diode or the like. Become.

Furthermore, if the ink cassette 4 is not loaded in the loading section, the remaining amount of ink will be displayed as "no remaining ink", so this display can also be used to detect the presence or absence of the ink cassette 4.

As explained above, according to the present invention, the flat plate is arranged in contact with the ink storage bag, and the movement of the flat plate accompanying the change in the remaining ink level is detected to detect the remaining amount of ink. The additional simple means does not increase the cost of the ink cassette, and since a flat plate is used, the flexible ink bag does not partially collapse, making it possible to accurately detect the remaining amount of ink. Further, since the remaining ink amount detection mechanism itself such as the detection circuit is arranged on the main body side and can be used repeatedly, it is possible to provide an inkjet printer equipped with an inexpensive and reliable ink remaining amount detection means.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing the structure of a general ink cassette, Fig. 2 is a partially enlarged sectional view showing the detailed structure of an ink storage bag, and Figs. 3 a to c are a conventional liquid remaining amount detection mechanism. FIG. 4 is a configuration diagram showing the configuration of the ink remaining amount detection device according to the present invention, and FIG. 5 shows another embodiment of the present invention in which the ink remaining amount is detected by swinging of an arm piece. FIG. 1... Ink storage bag, 2... Ink, 5... Output pipe, 6... Rubber stopper, 7... Insertion needle, 19...
...Permanent magnet piece, 20... Arm piece, 22... Flat plate, 23... Reed switch, 25... Light emitting diode.

Claims (1)

[Scope of Claims] 1. A loading section for an ink container which is removably attachable to an inkjet printer and stores ink to be supplied to a recording head, and a detection means for detecting consumption of ink in the ink container. In the inkjet printer, a flexible ink bag that stores ink and is displaced according to consumption of the ink is stored inside the ink container, and at least a central area of the upper surface of the flexible ink bag contains A plate-shaped member that is displaced together with the ink bag, and a displacement member that contacts the plate-shaped member and is displaced as the plate-shaped member is displaced, and the displacement state of the displacement member is detected by the detection means. An inkjet printer characterized by detecting the amount of ink remaining. 2. The inkjet printer according to claim 1, wherein the detection means is a detection circuit including an element for detecting displacement of the displacement member. 3. The inkjet printer according to claim 1, wherein the detection means is performed by visually observing the amount of displacement of the displacement member itself. 4. The inkjet printer according to claim 1, wherein the detection means also serves to detect the presence or absence of an ink container.