JPH02198868A - Ink-jet recorder - Google Patents

Abstract

PURPOSE:To detect the residue of ink accurately even when ink having different ink compositions is used by providing an ink-jet recording head and/or an ink tank with a means correcting a current value or a resistance value to a fixed value. CONSTITUTION:Resistance is corrected by adding a correction resistor to a detecting section on the head side in the change of the resistance value of ink due to the compositions of ink, the difference of the mixing ratios of solvents, thus equalizing resistance output characteristics to a printer body. A recording head chip 1 and an ink tank 9 are installed detachably and there is no absorber on the recording head chip side in a cartridge, 7A is supported from an upper section and 7B from a lower section and tabular ink-residue detecting electrodes 7A, 7B are arranged into an ink supply chamber, and ink resistance between 7A-7B altering by the height (h) of a level is detected, thus detecting residue. Correction resistance RB is varied in accordance with the change of the resistance values of each ink, thus keeping an apparent resistance value constant at all times, then accurately detecting residue amount even to the alteration of the kind of the ink to be used.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an inkjet recording device, and more particularly to an inkjet recording device that includes ink remaining amount detection that improves false detection due to changes in ink components.

[Prior Art] Conventionally, in an inkjet recording apparatus, the following method has been used to detect the amount of ink remaining.

■Method of detecting ON10FF-like resistance changes depending on the presence or absence of ink between two electrodes. ■A method for detecting analog resistance changes in the volume resistance of ink between two electrodes. ■Detection method using analog resistance changes between two electrodes in the absorber.

[Problems to be Solved by the Invention] However, the conventional method has the following drawbacks.

In the case of ■ and ■, vibrations caused by carriage movement and
11H causes the ink level to be in a waving state, leading to erroneous detection.In the case of ①, the erroneous detection due to vibrations and impulses has been improved; (changes in composition due to differences in color or paper) cause changes in the volume resistance of the ink, leading to false detection.

[Means for Solving the Problems] According to the present invention, an inkjet recording head and/or an ink tank provided with at least two electrodes in an ink flow path, and a current value or resistance value between the two electrodes are detected. In the inkjet recording apparatus, the inkjet recording head and/or the ink tank may include a correction means for correcting the current value or resistance value to a predetermined value. This makes it possible to accurately detect the remaining amount of ink even if inks with different ink compositions are used in the same head.

The remaining amount may be detected in the head section or in the tank section, and an absorber may be placed in the head and the ink tank. The correction circuit may include a circuit that exhibits a resistance change equivalent to that of ink for correction. Furthermore, the temperature of the printing device or the ink may be monitored, and correction may be made in response to changes in the resistance of the ink due to temperature, thereby accurately detecting the remaining amount.

[Example] The present invention will be described below by way of examples with reference to the drawings.

Example 11 Out of 1 In this embodiment, the change in resistance value of the ink due to the difference in ink color 5, that is, the dye, is corrected by distance by changing the position of the electrode for the frame structure on the head side. They have the same output characteristics.

FIG. 1 shows a disposable type inkjet recording cartridge.

In FIG. 1, 1 is a recording chip, and 2 is an ink ejecting unit that has the function of ejecting ink, including an ejection port for ejecting ink and a thermal energy used to generate droplets. It has an energy generating element. 3 is a liquid chamber for temporarily storing ink in order to send ink to the ink discharge section; 4 is a channel for sending ink to the liquid chamber; 5 is a filter for removing air bubbles, dust, etc. Reference numeral 6 denotes an ink absorber made of a porous material or a fibrous material, in which pin-shaped remaining ink amount detection electrodes 7a, 7b, 7c, and 7d are provided for detecting the amount of ink absorbed.

7e and 7f exist. Details of the method of switching these sensing electrodes will be described later. The above constitutes the recording chip 1. Next, 9 is an ink tank,
It contains an absorber 6' and an amount of ink of 0. The ink tank 9 and recording chip 1 are configured to be detachable via an insertion bottle 8 or the like. Here, 14 is an 0 ring to prevent ink leakage. The ink tank 9 is designed so that ink does not leak out when it exists alone, and the ink flows out when the RAD chip is inserted into recording.

The ink tank 9 has an ink absorber 6' placed inside it so that the water head pressure of the ink tank 9 itself can be adjusted so as not to apply water head pressure to the RAD chip 1 during recording, thereby enabling downward printing. There is.

Next, a specific method for detecting the remaining amount of ink will be described.

When the ink in the ink tank 9 is consumed by printing, recovery operations, etc., and the amount of ink in the ink tank 9 decreases, the amount of ink introduced to the ink absorber 6 also decreases, and the amount of ink absorbed in the ink absorber 6 decreases. When the amount of ink decreases, small air bubbles are mixed in, and the electrical resistance between the remaining amount detection electrodes 7a and 7b gradually increases.Therefore, as the current between them decreases, it is possible to detect that the remaining amount of ink has reached the limit value. . By monitoring the current value at this time, the ink remaining [
It can be seen that there is a relationship between tIL and ink resistance R as shown in FIG. A, B, and C in Figure 2.

Each curve in D shows the difference in ink color (difference in dye), and A is Black ink (dye concentration 3.0%);
B is Red ink (dye concentration 2.5%), C is Btus
Ink (dye concentration 2.5%), D is Green ink (
Dye concentration 2.0%), E is flesh colored ink (dye concentration 2.5%)
%). What can be seen from Figure 2 is that because the volume resistance of each ink differs depending on the color of the ink, if you try to detect the remaining amount only between 7a and 7b, the remaining amount will be detected with the same resistance value RR. If this is activated and the remaining amount lamp (not shown) is turned on, there will be a difference in the remaining amount of ink for each ink of A, B, C, and D, which is not preferable.

If the remaining amount detection is to be performed for any of A, B, C, and D inks at a certain level of remaining amount, each A, B, C, and D ink.

The difference in the resistance values of inks B, C, and D is detected by changing the combination of electrodes using a switching device such as a switch. For example, when using ink D with a low resistance value, the distance between the electrodes is lengthened and the apparent resistance R= It would be better to increase P- (P: resistivity, iL: length, S2 area), correct the curve as a whole, and make the remaining amount detection light up when the resistance value is RR. ,
When using ink A with a high resistance value, conversely, shorten the distance between the electrodes to reduce the apparent resistance and correct the overall curve so that the remaining amount detection is activated when the resistance value is R7. Furthermore, for inks E having different resistance values, the electrode positions may be similarly combined so that the remaining amounts are the same when the resistance values are R and t.

At this time, it is desirable that the combinations be arranged vertically (or diagonally arranged) with respect to the direction of gravity. FIG. 3 shows a graph of resistance values measured in the vertical and horizontal directions with respect to the direction of gravity.

It goes without saying that the distance between the sensing electrodes shifts in the α direction as the distance becomes longer, and in the β direction as the distance becomes shorter.

It is desirable that the surface of the detection electrode be made of a material with high contact resistance, such as SUS, gold plating, or platinum. By the way, the distance between the electrodes varies depending on the structure of the absorber 6 of the chip, but it is between 5 and 3.
The resistance value of the ink is preferably about 0 am, and the resistance value of the ink at this time is several tens to hundreds of Ω. In a printing device that prints using this cartridge, C
Replace the ink with B ink and change the electrode position to 7a-7
After switching from B to 7a-7d and turning on the remaining amount lamp again, I checked the remaining amount of ink in both ink tanks.
There was almost no difference. However, after converting to a different ink, the ink is suctioned and replaced through a certain recovery sequence.
It is desirable to complete the chromaticity adjustment before printing. Furthermore, by performing the same operation when replacing the ink tank during printing, it is now possible to accurately detect the remaining amount.

In addition, the remaining ink level detection circuit of the present invention may generate bubbles due to ink electrolysis if it is constantly energized, so it is preferable to configure it as shown in the circuit diagram shown in Figure 4. By reversing the polarity for each measurement, the generation of bubbles due to electrolysis can be completely eliminated. The time required for one measurement is approximately several m5ec.

FIG. 5 is a diagram showing a second embodiment of the present invention. In this embodiment, resistance is corrected by attaching a correction resistor to the head-side detection unit to compensate for changes in ink resistance due to differences in ink composition, that is, differences in solvent mixing ratio, and the resistance output characteristics to the printer body are made the same. This is what I did.

Figure 5 shows a disposable type inkjet.
This is a self-recorded cartridge. This cartridge also has a recording chip 1 and an ink tank 9 that are detachable. Since this cartridge does not contain an absorber in the ink tank, the water head pressure in the tank must be maintained by the meniscus of the nozzle in the ejection section, so it is of the horizontal printing type. Example 1 for removing S
This can be done in a similar way. The feature of this cartridge is that there is no absorber on the recording head chip side, and there is a plate-shaped remaining ink amount detection electrode 7A in the ink supply chamber.

7B is arranged so that 7A is supported from the top and 7B is supported from the bottom, and the height h of the liquid level shown in FIG. 6 changes. The remaining amount is detected by detecting the ink resistance between A and 7B.

For example, if the ink tank composition is optimized for each ink such as plain paper ink, coated paper ink, TP ink, etc.
Since each ink is different, the resistance value of the ink changes. By making the correction resistor R8 variable in response to this change in resistance value, it was possible to keep the apparent resistance value constant at all times and to accurately detect the remaining amount even when ink was changed.

Although a simple correction circuit is added to the head side here, the correction may be performed by a circuit equivalent to the ink. Although a variable type correction resistor was used, correction may be made by switching resistors connected in series or in parallel.Switching may be done manually or automatically.

Embodiment 3 FIG. 7 is a diagram showing a third embodiment of the present invention. In this embodiment, a correction resistor R8 is attached to the remaining amount detecting device on the tank side to cope with changes in the ink resistance value due to changes in the dye concentration of the ink. The inkjet recording apparatus shown in FIG. 7 is a permanent type head, and a recording head 1 and an ink tank 9 are connected to a supply tube 12.
It is maintained by

This is designed to reduce the number of electrical components in the head, increase the reliability of the head itself, and prevent bubbles from entering the head by detecting the remaining amount on the tank side. This makes it possible to prevent printing defects (non-ejection, etc.) due to bubbles entering the head ejection section due to erroneous detection of remaining amount.

[Effects of the Invention] As explained above, in the ink remaining amount detection device that detects the remaining ink amount based on the ink resistance value, it is possible to correct the ink resistance value at the recording head or tank portion, so that the ink composition can be adjusted. Even if the ink changes, the resistance output characteristics to the main body side can be kept constant, making it possible to accurately detect the remaining amount of ink even if a large number of inks are used without replacing the head.

It has also become possible to prevent printing defects due to false detection.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a cartridge with ink remaining amount detection and correction according to the present invention; Figs. 2 and 3 are diagrams showing the relationship between ink remaining amount and ink resistance; Fig. 4 is a remaining amount detection circuit; The figure is a schematic diagram of a cartridge showing a second embodiment of the present invention, Figure 6 is a perspective partial cutaway view of a cartridge showing a second embodiment of the present invention, and Figure 7 is a schematic diagram of a cartridge showing a third embodiment of the present invention. FIG. 2 is a schematic diagram of a head tank showing an example. 1... Recording Radchip 2 - Ink discharge section 3 - Liquid chamber 4 - Channel 5 - Filter 6.6° - Absorber 7 - Ink remaining amount detection electrode 8 - Insertion bottle 9 - - Ink tank 10 - Ink 11 - Lead frame 12 - Supply tube 13 - Ink remaining amount detection circuit 14 - 0 ring Figure 1 Figure Figure

Claims (1)

[Claims] 1. An inkjet recording head and/or an ink tank provided with at least two electrodes in an ink flow path, and detecting the amount of ink remaining by detecting the current value or resistance value between the two electrodes. An inkjet recording apparatus comprising: a remaining ink amount detecting means for performing the following; and an inkjet recording apparatus, wherein the inkjet recording head and/or the ink tank has a correction means for correcting the current value or the resistance value to a predetermined value. Device. 2. The inkjet recording apparatus according to claim 1, wherein the composition of the ink varies depending on the color tone of the ink.