RU2268150C2 - Device for monitoring of ink consumption in cartridge - Google Patents

Abstract

FIELD: printing engineering, in particular, printing (printers) with a thermojet printing head.

SUBSTANCE: the device is applicable in cartridges with a reservoir for ink with flexible walls, in which a stable negative pressure is maintained. For maintaining of a stable negative pressure in the reservoir use is made is made of a single component fulfilling simultaneously the functions of the reservoir walls and the controller of negative pressure in the reservoir. An arched spring structure is used for the purpose that forms the side walls of the reservoir. A bulge-ridge is positioned on the apex of the arch, which passes through the groove of the outer casing and has notches corresponding to different levels of reservoir filling with ink.

EFFECT: simplified means of monitoring of ink consumption in the cartridge, and enhanced adaptability to their manufacture.

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Description

The invention relates to the field of printing technology, and more particularly to printing devices (printers) with a thermal inkjet print head, into which liquid ink is supplied from a container (cartridge).

In known inkjet printers that use a working fluid (inkjet printers), the printing process is carried out by supplying droplets of ink coming from the nozzle of the print head. The ink supply is stored in the tank, which performs two main functions: (1) to protect the ink from drying out and (2) to ensure a constant ink flow to the print head. A number of well-known technical solutions in this area (see US patent No. 5767882 [1] US patent No. 5757406 [2] significantly increased the performance of the cartridges.

At the same time, such an urgent problem for the consumer as control over the ink consumption in the cartridge turned out to be practically out of sight of developers of peripheral devices for computers.

Apparently, it is impossible to consider a technical solution to determine the ink consumption by the time elapsed since the start of using the cartridge, although at the moment most cartridge manufacturers offer the consumer to use this particular method.

A known attempt to solve the problem of controlling ink consumption by counting the ink droplets spent during operation. In the patent application of the Japanese corporation Seiko Epson (RU 99124807) [3] this calculation is carried out using software methods, which significantly complicates the design and allows the use of such a cartridge only in printers with a special interface.

A description of the mechanical ink flow indication system can be found in US Patent No. 5,757,406, owned by Hewlett-Packard, [4]. In the text of the description there is a mention of two indicator strips glued to the side walls of the ink tank. When the walls are compressed by atmospheric pressure due to the exit of ink, the strips are mutually moved, providing visual control of ink consumption. The design that implements this control method is quite simple, however, it requires several additional operations in the manufacture of the cartridge. This system is selected as a prototype of the claimed invention.

The prototype describes an ink supply system using the negative pressure effect, including an inelastic flexible ink tank, in which springs and struts are placed that resist collapse of the tank under the influence of atmospheric pressure during ink outflow (arising under the influence of mainly capillary forces). As the tank is emptied, its shell folds “into an accordion,” with only two wide side walls in contact with spring-loaded struts having rigidity. The specified design determines the choice of method for controlling ink consumption in the tank: the level of ink consumption is determined by the degree of convergence of the two rigid walls.

Structurally, this is accomplished by fixing on two wide sides of the tank two tapes, in which the upper loose ends are thrown over the upper part of the tank "overlap". Through a special window in the rigid case of the cartridge track the mutual movement of the tapes in the process of convergence of the walls of the tank, which allows you to judge the degree of emptying of the tank.

The described device is quite effective when used in the design of the cartridge with a tank-accordion. However, in more modern designs, in which the device for creating negative pressure is directly elastic walls, it is possible to simplify the design of the device for controlling ink consumption in the cartridge.

The claimed invention is aimed at creating a simple and technologically easy-to-implement device for controlling ink consumption in such modern designs.

The cartridge described in [3], assumes the presence of a reservoir with elastic side walls, providing the creation of negative pressure in the reservoir. Moreover, the design of the tank has the property to change its dimensions when the side walls come closer. The proposed design is based on the control of changes in the height of the arch structure of the tank relative to the fixed edge of the rigid housing of the cartridge.

Figure 1 presents the structural elements of the device, where

1 - rigid base of the cartridge,

2 - cartridge output channel of the cartridge;

3 - filter;

4 and 5 - flexible end walls of the ink tank;

6 is an arched spring structure forming the side walls of the ink tank (hereinafter, the tank itself is also designated, since the presence of the end walls and the base is not essential in this context);

7 - the outer housing of the cartridge.

Figure 2 shows a cross section of the tank (a shape close to arched) in the initial phase and in the stage close to the final collapse, where ΔH denotes a change in the height of the tank.

Figure 3 shows the node of the movable mounting of the tank to the outer casing, where

6 - side wall of the arch design of the ink tank;

7 - outer case;

8 - protrusion-crest of the arch design of the ink tank;

9 - groove of the outer case of the cartridge.

Figure 4 presents the elements of a device for determining ink consumption, where

10 - protrusion of the outer housing of the cartridge;

11 - hole in the protrusion of the outer housing of the cartridge;

12 - hole in the protrusion ridge of the arch design of the ink tank;

13 - a bracket;

14 - a radiating element of an optoelectronic pair;

15 is a photodetector element of an optoelectronic pair.

As follows from figures 1 and 3, the arched design of the tank (6) at its apex has a protrusion-crest (8), and the outer housing of the cartridge (7) has a groove (9), in which the crest can move in the direction from the bottom to the top compression of the arch and increasing its height (ΔH in figure 2).

The presence of a protrusion ridge (8) and a groove (9) is caused by the desire of the developers of the design [3] to provide an additional margin of rigidity in the upper part of the tank, taking into account the accelerations experienced by the cartridge during rapid movements along the printer carriage. The protrusion / groove design leaves only one degree of freedom for the upper part of the tank - translational upward movement. On the other hand, the upward movement of the ridge-ridge is correlated with a change in the volume of the tank.

The method of controlling the ink consumption in the tank (6) is that the protrusion-comb (8) is graduated, and in the process of ink consumption, the height of the rise of the protrusion-comb (8) is noted, thereby determining the reduction in the volume of the tank (6) and, therefore, ink consumption.

An advantage of this method is the possibility of its implementation without introducing any special devices into the standard cartridge design.

The method can be based both on visual observation, when the movement of the protrusion-ridge (8) is visually noted in the groove (9), and on the use of an optoelectronic pair, when a radiating element (14) is placed on opposite sides of the ridge-ridge (8), and a photodetector element (15). The change in the current strength in the element (15) with a different degree of its illumination (is shaded as the protrusion-crest 8 extends) allows you to display data on ink consumption on an automatic indicator device or on a computer. In the second case, the method loses its main advantage - the lack of new parts or devices, but provides automation control.

For a more accurate quantitative assessment of the filling of the reservoir (6), it is proposed to apply risks or multi-colored sectors to the ridge-crest (8).

In an improved embodiment, along with the risks or instead of notches in the ridge-crest, a through hole is made, preferably of a triangular shape, with the apex of the triangle pointing up or down (see element 12 in FIG. 4). At the same time, it remains possible to visually control ink consumption by the degree of increase in the area of the visible triangle, and there is an additional opportunity to automate control through the use of an optoelectronic pair.

In a practical embodiment, the optoelectronic pair was placed on a removable bracket 13 (Fig. 4). The radiating element (14) was placed on one side of the bracket (13), and the photodetector element (15) was located on the other side of the bracket (13). A hole in the shape of a right-angled triangle (12), cut in the plane of the protrusion-ridge (8), was located between the elements of the optoelectronic pair. A significant part of the triangular hole (12) was located below the level of the groove (9) in the outer case of the cartridge (7). In the process of ink consumption, the protrusion-crest (8) rose, revealing an increasingly large area of the triangular hole (12) through which the radiation of the radiating element (14) passed. The change in the illumination of the photodetector element (15) and, accordingly, the change in the output signal was recorded programmatically (the optoelectronic pair is not shown in the drawings).

The advantage of placing the optoelectronic pair (14) and (15) on the removable bracket (13) is that in the absence of an interface with the output signal software, the bracket (13) is not worn and the control is carried out visually. In addition, the bracket (13) does not apply to consumables, so if you have one bracket (13), you can use replaceable cartridges that are not equipped with a bracket (13) in order to save money.

The option of placing the optoelectronic pair not on the cartridge, but on the printer carriage (not shown in the drawings) also proved to be workable. The advantage, as in the previous version, is that in the presence of a stationary optoelectronic pair, cheaper cartridges can be used that do not include a bracket (13).

Claims (4)

1. An ink flow control device in a cartridge including an outer casing, a rigid base attached to the outer casing, an ink reservoir mounted on a rigid base and provided with a device for maintaining negative pressure in the reservoir, characterized in that the device for maintaining negative pressure is made in the form arched spring structure, forming the side walls of the tank with flexible end walls, and at the top of the arch there is a ledge-crest passing through the groove of the outer mouth and having risks corresponding to different levels of filling the tank with ink. 2. The device according to claim 1, characterized in that the protrusion-comb is provided with an opening. 3. The device according to claim 2, characterized in that the movement of the protrusion-comb is controlled by passing through the hole of the protrusion-comb radiation generated and detected by an optoelectronic pair, the elements of which are placed on opposite sides of the bracket covering the protrusion-comb. 4. The device according to claim 2, characterized in that the movement of the protrusion-comb is controlled by passing through the hole radiation generated and detected by an optoelectronic pair located on the printer carriage.

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