JPS59194855A - Detector for residual ink - Google Patents

Abstract

PURPOSE:To detect residual ink in a flat ink container with a high accuracy by a method in which a sheet is set between the inner surface of cassette and an ink bag, and the positions of the sheet varying with the reduction of ink amount are detected. CONSTITUTION:When an ink bag 1 filled with ink 2, a sheet 19 is pressed upwards in the ink bat 1. Since a detector plate 19b is also positioned above a hole 22, light emitted from a luminous means 23 is received by a light receiver 24, the residue of ink is detected by signal from the light receiver 24, and the detected results are notified by an alarm 28. On the other hand, as ink is used, the sheet 19 is pushed downwards by a spring 19a provided to both ends, the detector plate 19b is projected from the hole 22 to interupt the light path, signal from the light receiver 24 is stopped, the absence of residual ink is detected, and the detected results are notified by the alarm 28. Even when a magnetic detector is used for the optical detector, the same effects can be obtained.

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 OF THE INVENTION Conventionally, inkjet printers record information such as letters and pictures as dots by colliding liquid ink with the information to be recorded on paper in the form of droplets.

Therefore, the ink must be stored in liquid form, like gasoline in a car.Furthermore, when the ink is ejected, the ink scatters and contaminates the surrounding area, so the ink container must be carefully stored to prevent the ink from leaking due to vibrations or shocks. It is necessary to store it in Furthermore, since the ink must be stored so that its physical properties, such as surface tension, viscosity, PI-1, etc., are constant values, it is necessary to prevent evaporation and deterioration of the ink components 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 shown in FIG. 2 is known. 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 drawn out by connecting the insertion needle 7 to the outlet pipe 5 led to the rubber stopper 6. This ink storage bag 1 has a thickness of 5 mm, for example, as shown in FIG.
~10 μm nylon ultraviolet protection plastic thin film 8
, an aluminum thin film 9 with a thickness of about 10 μm to prevent ink evaporation and deterioration due to ultraviolet rays, etc.;
It consists of an inner main bag 10 made of a polyethylene thin film with a thickness of 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 image changes by a maximum of about 10 mm from the time it is full to the time it is empty, and is constructed so as to minimize the change in pressure.

When an ink storage container configured in this manner is connected to an inkjet printer for recording, it is known that when the remaining amount of 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 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 residual liquid 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 ink. Further, in the mechanism shown in FIG. 3(b), a light emitting means 16 and a light receiving means 17 are used instead of the reed switch 14.
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 liquid. This is the way to do 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.
17) - This method detects resistance changes due to decrease and takes advantage of the fact that the resistance value suddenly increases when the remaining amount becomes low.

However, such conventional liquid residual detection methods cannot be used to detect residual ink contained in a flat type of 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 Fig. 3 (C), even if the ink is low and completely gone, there is a risk that the resistance will decrease due to the ink adhering to the inside of the ink storage bag, so it is difficult to accurately detect the remaining amount of ink. Can not do it.

Purpose Therefore, the present invention solves such conventional drawbacks, and an object thereof is to provide an ink residual detection device that can accurately detect residual ink in an ink storage container using inexpensive means. do.

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

FIG. 4 is an exploded perspective view showing the basic structure of the residual ink detection device according to the present invention, showing the ink storage bag 1 stored in the ink cassette 4 shown in FIG. 1 and its top surface. A sheet member 19 placed on the seat 1a is shown.

As described above, the ink storage bag 1 has a discharge pipe 5 and a rubber stopper 6 at its end so that the ink can be discharged to the outside.

On the other hand, the sheet member 19 is made of a thin plate made of a material having appropriate elasticity, such as a polyester sheet, and its opposing ends are each bent into a U-shape in cross section to form a spring portion 19a, and its elastic The degree can be arbitrarily determined by selecting the width A of the spring part 19a and the thickness of the sheet part 19, but when stored together with the ink storage bag inside the ink cassette, the upper surface 1a of the ink storage bag is always A notch is provided at the other end to avoid contact with the outlet pipe 5 when the ink decreases, except for the spring part 19a that keeps it horizontal and responds to the decrease in ink and does not prevent normal ink discharge. 19C, and a detection plate (actuation plate) 19b bent downward at right angles to the sheet member is provided at the opposite end thereof.

The sheet member 19 configured as described above is an ink storage bag 1.
is placed on top of the ink cassette and stored in the ink cassette.

FIGS. 5(a) and 5(b) show the notebook member 19 stored in the ink cassette together with the ink storage bag in this manner.
FIG. 5(a) is a sectional view seen from the direction of the detection plate 19b showing the state in which the ink storage bag 1 is filled with ink 2. FIG. Sheet member 19 as shown in the figure
In response to the upper surface 1a of the ink storage bag 1 being pushed upward due to the filled ink, the spring portions 19a at both ends of the sheet member 19 are also pushed upward. Upper space 2 inside the ink cassette depending on movement
It is stored in a compressed state of 0 and 21. In this case, the detection plate 19b provided on the sheet member 19 is housed within the ink cassette and does not protrude to the outside.

Next, when the ink 2 in the ink storage bag 1 is completely consumed, as shown in FIG.
9 is pressed in response to the decrease in ink as described above, and as a result, the detection plate 19b protrudes to the outside of the ink cassette.

The basic structure of the present invention has been described above, and specific embodiments will be explained in detail below with reference to the drawings.

In the drawings shown below, the same parts as in FIGS. 1, 4, and 5 are denoted by the same reference numerals, and the explanation thereof will be omitted.

First Embodiment FIG. 6 shows a first embodiment of the present invention. As already explained, the ink cassette 4 includes an ink storage bag 1 and a sheet member placed thereon. A hole 22 is provided in the bottom of the ink cassette 4 at a portion corresponding to the detection plate 19a of the notebook member 19.

On the other hand, a light emitting means 23 (for example, an LED, etc.) and a light receiving means 24 (for example, a phototransistor, etc.) are arranged close to the hole 22 so as to face each other with a predetermined distance therebetween, and each conductive wire 26, 27 is connected to the remaining ink detection section. It is electrically connected to 25. The notification section 28 is activated by a signal from the remaining ink detection section, and is composed of an optical display device, an audible alarm device, or the like.

Next, the operation of the residual ink detection device configured as described above will be explained. As shown in FIG. 6, when the ink storage bag 1 is filled with ink 2, the sheet member 19 is pressed upward against the ink storage bag 1, and therefore the detection plate 19b also has a hole. Since it is located above the light emitting means 22, the light emitted from the light emitting means 23 is transmitted to the light receiving means 24.
The remaining ink detection device receives light from the light receiving means 24.
Remaining ink is detected based on the signal. Also, the notification section 28 notifies the user of the detection result.

On the other hand, Figure 7 shows a state where the ink has been used and there is no remaining ink. That is, in response to the decrease in ink, the notebook member 19 is pressed downward by the spring parts +98 provided at both ends thereof, and the detection plate 19b also moves downward and protrudes from the hole 22. becomes. The optical path between the light emitting means 23 and the light receiving means 24 is blocked by the detection plate 19b protruding from the hole 22, and the signal from the light receiving means 24 is also stopped.

The residual ink detection section 25 detects that no ink remains by stopping the signal from the light receiving means 24, and the notification section 28 notifies the user of the detection result.

As is clear from the above description, in the present invention, a sheet member having a simple structure is placed on an ink storage bag and incorporated in an ink cassette, and a detection means for detecting a response of the sheet member to a decrease in ink level. The system attempts to detect the presence of ink by providing a sensor, which eliminates the need for moving parts and expensive parts that lack precision, as seen in conventional ink remaining detection devices, and also reduces the risk of failure. By employing highly accurate non-contact detection means, it is possible to provide a residual ink detection device that has many effects such as high reliability and durability, low cost, and stable operation.

In this embodiment, if the light receiving means 24 is adopted as a light receiving means whose output changes depending on the amount of received light, the amount of remaining ink can be determined not only by the presence or absence of the remaining ink but also by the degree of protrusion of the detection plate 19b. It is also possible to detect.

Second Embodiment FIG. 8 shows a second embodiment of the present invention, in which the ink cassette 4 is shown in FIG.
A structure is adopted in which residual ink is detected through a similar hole 29 provided in the side wall instead of the hole 22 provided at the bottom of the printer.

A light emitting means 23 and a light receiving means 24 are installed in the vicinity of the hole 29, and the remaining ink detecting section 25,
Furthermore, it is electrically connected to the notification section 28. The positions of the light emitting means 23 and the light receiving means 24 are such that when the detection plate 191 of the sheet member 19 closes the hole 29, the light emitted from the light emitting means 23 is reflected by the detection plate, as will be described later. It is relatively determined so that the light is received by the light receiving means 24. FIG. 8 shows a state in which the ink storage bag 1 is filled with ink 2, and the notebook portion 19 is pressed upward, so that the detection plate 19b is also located upward accordingly. In this state, the light emitted from the light emitting means 23 passes through the hole 29 and does not reach the light receiving means 24. Therefore, the light receiving means 24 does not emit any signal, and the remaining ink detection section 25 The notification unit 28 detects the remaining ink and notifies the user of the detection result.

On the other hand, FIG. 9 shows a state in which the ink 2 in the ink storage bag 1 has been completely consumed and there is no remaining ink, and in this state, the sheet member 19 is pressed downward by the spring portion 19a of the sheet member 19. and detecting plate 191 accordingly.
] also falls downward, covering the hole 29 and blocking the optical path of light emitted from the light emitting means 23. The light emitted from the light emitting means 23 is reflected by the detection plate 19b and received by the light receiving means 24, and sends a signal to the remaining ink detecting section 25. The remaining ink detecting section 25 detects that there is no ink remaining and sends a signal to the notifying section. 28 notifies the user of the detection result. In this case, as is clear from the figure, the length of the detection plate 19b may be long enough to cover the hole 29 and reflect the light from the light emitting means 23 when no ink remains; It must be appropriately short so as not to cover the hole 29 in a state where ink remains.

It goes without saying that the residual ink detection device of the second embodiment configured and operated as described above has the same effects as the first embodiment.

Third Embodiment FIG. 10 is a diagram showing a third embodiment of the present invention, in which magnetic detection is used instead of the optical detection means used in the first and second embodiments. Means is configured to sense actuation of the sheet member.

In this embodiment, a magnetic material 30 is attached to the detection plate 19 [ ) of the sheet removal 19 by a known method such as adhesion or coating, and the bottom of the ink cassette 4 is provided with a magnetic material 30 . A hole 31 is drilled through which the detection plate 19b having a body 30 enters and exits.

Furthermore, a magnetically sensitive means 32 (for example, a reed switch, etc.) is disposed close to the hole 31, and is electrically connected to the notification section 28 via the residual ink detection section '25 by conducting wires 26 and 27. FIG. 10 shows a state p, 1 in which the ink storage bag 1 is filled with the ink 2, the notebook part 19 is pressed upward, and therefore the detection plate 19b having the magnetic material 30 is shown.
Accordingly, it is also located upwards. In this state, the magnetic body 3o adhering to the detection plate 19
Since the id of the two is different from each other, the magnetic sensing means 32 does not sense the magnetic force and therefore does not generate a signal. Ink remaining detection section 2
5, since the magnetic sensing means 32 does not generate a signal, the remaining ink is detected, and the notification section notifies the user of the detection result.

On the other hand, FIG. 11 shows a state in which the ink 2 in the ink storage bag has been completely consumed and no ink remains. In this state, the sheet member 19 is pressed downward by the spring portion 19a of the sheet member 19. , accordingly the detection plate +9
As a result, the magnetic sensing means 32 detects the detection plate +
A signal is generated in response to the magnetic force of the magnetic body 30 attached to the magnetic body 9b. The residual ink detection section 25 detects that no ink remains based on the signal, and the notification section 28 notifies and warns the user of the detection result.

Even in this embodiment, which is constructed and operates as described above, it is possible to expect exactly the same effects as in the first and second embodiments.

Effects As is clear from the detailed explanation above, in the present invention, in order to detect residual ink, a sheet member having appropriate elasticity is placed on the top surface of the ink storage bag, and the sheet member is placed on the top surface of the ink storage bag. By providing a plate that moves in conjunction with movement and by adopting a non-contact detection means to detect the reaction of the sheet member as ink decreases, the drawbacks of conventional ink remaining detection devices can be eliminated. Furthermore, since the structure is simple, it is possible to provide a highly accurate residual ink detection device that is less expensive than conventional methods, has fewer failures, is highly reliable and durable.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an ink cassette incorporating 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 of Fig. 1, and Figs. 3 (a) to (c). 4 is an exploded perspective view showing the structure of the device of the present invention, and FIG. 5 (a: l 5
(L)) is a sectional view for explaining the operation of the sheet member used in the apparatus of the present invention, in which FIG. 5(a) is when ink remains, and FIG. 5(b) is when there is no ink remaining. 6 to 11 show embodiments of the apparatus of the present invention, FIG. 6 is an explanatory diagram showing the structure of the first embodiment when ink remains, and FIG. 7 is a diagram showing the structure of the first embodiment. FIG. 8 is an explanatory diagram of the second embodiment when there is no ink remaining. FIG. 9 is an explanatory diagram of the second embodiment when there is no ink remaining. 10 are explanatory diagrams showing the third embodiment when ink remains, and FIG. 11 is an explanatory diagram of the third embodiment when there is no ink remaining. 1 - Ink storage bag 2... Ink 4... Ink cassette 19 - Note member 19a... Spring part
19b...detection plate 22.29.31...hole 2
3... Light emitting means 24... Light receiving means 25 Ink remaining detection section 28... Notification section 30. Magnetic body 32. Magnetically sensitive means.

Claims (1)

[Claims] 1) In an ink residual detection device that detects residual ink in an ink bag stored in an ink cassette, a sheet material is arranged between the inner surface of the cassette and the ink bag, and as the amount of ink decreases, An ink residual detection device characterized in that residual ink is detected by detecting a changing position of a sheet through a non-contact detection means. 2) The residual ink detection device according to claim 1, wherein the non-contact detection means comprises a light-emitting and light-receiving element. 3) The residual ink detection device according to claim 1, wherein the non-contact detection means comprises a magnetically sensitive element.