JPH04212864A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To provide an ink jet device which enables prevention of entrance of refuse to the interior and the delivery port of a recording means and periodic removal of refuse in an ink feed system. CONSTITUTION:In an ink jet recording device to deliver ink from a recording means 1 to a material to be recorded and perform recording, an exchangeable filter 39 and a fixed filter 38 arranged closer to the recording means 1 than the filter and having meshes finer than that of the filter 39 are mounted between an ink storage part 4 of an ink feed system and the recording means 1. This constitution prevents entrance of refuse to the interior and a delivery port 30 of the recording means 1 and enables periodic removal of refuse in the ink feed system.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inkjet recording apparatus that performs recording by ejecting ink from a recording means onto a recording material.

0002

[Prior Art] Recording devices such as printers, copiers, and facsimile machines, which are used in combination with computers, word processors, etc., or used independently, print images on recording materials such as paper and thin plastic plates based on image information. It is structured in such a way that it continues to form.

[0003] The recording apparatus can be classified into inkjet type, wire dot type, thermal type, laser beam type, etc. depending on the recording method. Among these, the inkjet type (inkjet recording device) performs recording by ejecting ink from a recording means onto a recording material.
It has the advantages of being able to record high-definition images at high speed, producing less noise because it uses a non-impact method, and being easy to record color images using multi-color ink. There is.

In particular, inkjet recording means (recording heads) that use heat as ink ejection energy,
Electrothermal converters, electrodes, etc. formed on a substrate through semiconductor manufacturing processes such as etching, vapor deposition, and sputtering,
By forming the liquid path walls, the top plate, etc., it is possible to easily manufacture a device having a high-density liquid path arrangement (discharge port arrangement).

[0005] The ink supply system to the recording means (recording head) in the above-mentioned inkjet recording apparatus uses, for example, a recovery pump to supply an ink storage section (ink tank, etc.).
The ink is configured to be able to circulate between the recording device and the recording device. That is, a common liquid chamber that communicates with ejection ports (usually plural) is formed in the recording means, and ink in the ink storage section is introduced into the common liquid chamber through a supply path such as a tube, and the ink is introduced into the common liquid chamber through a supply path such as a tube. A return path allows for reflux from the common liquid chamber to the ink reservoir.

[0006] In the ink supply system constructed as described above, during a recording operation, the pump does not operate, and the ink in the ink reservoir is naturally supplied through the supply path by capillary action. Furthermore, during a recovery operation performed to remove air bubbles remaining in the supply system such as the recording head or tube, the pump is driven to forcefully feed ink to the recording head, and then from the recording head to the ink storage section. A circulation operation is performed in which the ink is returned.

[0007]

However, in the ink supply system of a conventional ink jet recording apparatus, a filter for removing dust is provided at the ink inlet/outlet of the recording head, but this filter cannot be replaced. Therefore, as the number of ink circulations increases, the amount of dust trapped in the filter increases, and if this condition continues, the filter may become clogged and ink may not be supplied to the print head. Ta.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent dust from entering the inside of the recording means and the ejection port, and to remove dust from the ink supply system. An object of the present invention is to provide an inkjet recording device that can be periodically removed.

[0009]

[Means for Solving the Problems] The present invention provides an inkjet recording apparatus that performs recording by discharging ink from a recording means onto a recording material, in which a replaceable ink storage section of an ink supply system and a recording means are provided. By installing a filter and a fixed filter that is disposed closer to the recording means than the replaceable filter and has a finer mesh than the replaceable filter, dust cannot enter the inside of the recording means or the discharge port. An object of the present invention is to provide an inkjet recording apparatus that can prevent such problems and periodically remove dust in an ink supply system.

0010

Embodiment FIG. 4 is a schematic perspective view showing the overall structure of an inkjet recording apparatus according to an embodiment of the present invention. This is a platen roller for conveying a sheet-shaped recording material and forming a recording surface. The recording material in the form of a continuous sheet or a cut sheet is transported by a pinch roller (not shown) that is pressed against the platen roller 12.
A conveying force is applied to the recording medium, and the recording medium is conveyed between the recording means (recording head) 1 and the platen roller 12.

[0011] The recording means 1 includes two guide rails 13a.
The carriage 2 is mounted on a carriage 2 that is reciprocally driven in the S direction in the figure along the recording area 13b, and the recording material Images are recorded. During this recording, one line of recording is performed while the platen roller 12 is temporarily stopped and the carriage 2 is scanned and moved with respect to the stationary recording material. When one line of recording is completed, the platen roller 12 is rotated by a predetermined amount to advance the line of recording material, and then the next line is recorded.

The carriage 2 is connected to a shaft 17 of a motor 16.
It is connected to a belt 19 stretched between a pulley 18a and an idle pulley 18b which are fixed to the same, and is driven back and forth along the platen roller 12 by driving the motor 16.

The illustrated recording means 1 is one for color recording consisting of a plurality of recording heads, for example, yellow (Y).
), magenta (M), cyan (C) and black (B
) four recording heads 1Y, 1 corresponding to the four color inks.
It is composed of M, 1C, and 1B (not shown). Each recording head that records these ink colors Y, M, C, and B includes tubes 6Y, 6M, which form an ink flow path on the supply side.
6C, 6B, and the tubes 7Y, 7M, 7C, and 7B that form the ink flow path on the return side, the corresponding color ink reservoirs (ink tanks, etc.) 4Y, 4M, 4C, and 4B
It is connected to the.

Note that the recording heads 1Y and 1M for each ink color
, 1C, 1B and ink storage section (ink tank) 4Y
, 4M, 4C, 4B, or supply side tubes 6Y, 6M, 6C, 6B and return side tubes 7Y, 7M, 7C, 7B, etc., which form ink flow paths for each ink color, will be collectively referred to below. or any one of them, omit the color codes Y, M, C, and B, and simply refer to the recording head 1, ink reservoir 4, and supply tube (ink flow path) 6. , a return side tube (ink flow path) 7, etc. Further, in FIG. 4, for the sake of simplicity, only the tube 7Y through which yellow ink flows is shown in the ink flow path 7 on the return side.

Pumps 5Y, 5M, 5C, and 5B for pumping ink from each ink tank 4 to each recording head 1 are connected in the middle of each tube 6 on the supply side. This pump 5 is used as a recovery pump that circulates ink in order to eliminate ejection failure due to clogging of the ejection ports of the ink ejection portion of the recording head 1. In this way, an ink supply system is configured between the ink tank 4 and the recording head 1.

A home position HP is set at a position within the moving range of the carriage 2 and outside the recording area, and at this home position, there is a On the other hand, a capping means 10 is arranged which can be moved in the direction of arrow f so as to press and separate.

The recording means (recording head) 1 is a recording means that discharges ink using thermal energy, and includes:
It is equipped with an electrothermal converter for generating thermal energy. Further, the recording means 1 performs recording by ejecting ink from an ejection port using pressure changes caused by growth and contraction of bubbles due to film boiling caused by thermal energy applied by the electrothermal converter. It is.

FIG. 5 is a partial perspective view schematically showing the structure of the ink ejection section of the recording means (recording head) 1.
In the figure, a recording means (recording head) 1 includes an electrothermal transducer 22 and an electrode 2 formed on a substrate 21 through a semiconductor manufacturing process such as etching, vapor deposition, and sputtering.
3. It is composed of a liquid path wall 24, a top plate 25, etc.

Recording ink 26 is supplied to an ink supply tube 6 from an ink storage section (ink tank, etc.) (not shown).
The liquid is supplied into the common liquid chamber 27 of the recording means 1 through the liquid. Reference numeral 28 indicates a connector of the tube 6 for supplying ink. The ink supplied into the common liquid chamber 27 is supplied into each liquid path 29 by capillary action, and the ink is supplied into each liquid path 29 through a discharge port 30 at the tip of each liquid path.
It is stably maintained by forming a meniscus. In each liquid path 29, the electrothermal converters 22 for heating the ink in the liquid path are arranged in one-to-one correspondence. Note that the reference numeral 31 indicates a discharge port surface (face surface) on which the discharge ports 30 are formed.

Here, when each electrothermal converter 22 is selectively driven (energized) in accordance with the image signal, the ink facing the energized electrothermal converter 22 is heated, and bubbles are formed by film boiling of the ink. Ink is ejected from the corresponding ejection port 30 using pressure changes caused by growth and contraction. The discharge port surface 31 has a predetermined gap (for example, about 0.3 to 1.5 mm).
5 mm) and faces the recording surface of the recording material.

In the inkjet recording apparatus shown in FIG. 4, the recording means (recording head) 1 is mounted on the carriage 2 in a positional relationship such that a plurality of ejection ports 30 are lined up in a direction intersecting the scanning direction (movement direction) of the carriage 2. It is installed in. In this way, the corresponding electrothermal converter 22 is driven (energized) based on the image signal or the ejection signal, and the ink in the liquid path 29 is brought to film boiling, and the pressure generated at that time causes the ejection port 3
A recording means (recording head) 1 is configured to eject ink from zero.

FIG. 1 is a schematic diagram showing an example of the configuration of an ink supply system of an inkjet recording apparatus according to the present invention. Inlet 34 of liquid chamber 27
The outlet 35 of the common liquid chamber 27 is connected to the ink tank (ink storage section) through the return tube 7.
It is connected to the return port 36 of No. 4. Supply side tube 6
A pump 5 for pumping ink to the common liquid chamber 27 is provided in the middle of the tube 7 on the return side, and a back check is provided in the middle of the return tube 7 to prevent ink from flowing back into the common liquid chamber 27. A valve 37 is provided. In this way, ink tank 4
An ink supply system is configured to circulate ink in the direction of the arrow.

A plurality of ejection ports 30 are formed on the ejection port surface 31 of the recording head 1, and each ejection port 30 communicates with the common liquid chamber 27 through its respective liquid path 29. Ink is ejected by selectively driving (energizing) the electrothermal converters 22 disposed in each liquid path 29 based on an image signal.

A filter 38 is provided near the inlet 34 of the common liquid chamber 27 to prevent foreign matter such as dust from entering the ink. Further, a replaceable filter 39 is provided at a predetermined position of the tube 6 on the ink supply side (in the illustrated example, between the pump 5 and the inlet 34 of the common liquid chamber 27). The filter 38 provided at the inlet 34 of the common liquid chamber 27 is a fixed filter that cannot be replaced, but the filter 39 provided in the tube 6 on the supply side is attached to be replaceable. Further, the fixed filter 38 is formed of a filter whose mesh is finer than that of the replaceable filter 39.

In the ink supply system shown in FIG. 1, when recording is performed with the recording head 1, the ink in the ink tank 4 flows through the tube 6 and the common liquid chamber 27 due to capillary action.
It is naturally supplied to each outlet 30 through the outlet. In addition, when performing a recovery operation, by operating the recovery pump 5, the ink in the ink tank 4 is transferred from the ink tank 4 → supply side tube 6 → common liquid chamber 27 → return side tube 7 → ink. Circulate to tank 4. In such an ink flow, dust present in the ink flow path on the supply side is first removed by a replaceable filter 39.

FIG. 2 is a longitudinal cross-sectional view of the replaceable filter 39 shown in FIG. In addition, the tube 6 is connected to the connector 4
It is removably connected to both end connection parts of 1. According to the filter 39 of FIG. 2, by periodically replacing the filter 39, dust inside the ink supply system can be removed.

In this case, it is necessary to prevent even minute dust that passes through the filter 39 from entering the recording head 1, so the inlet 34 of the common liquid chamber 27 shown in FIG.
The mesh of the fixed filter 38 is finer than that of the filter element 42 of the replaceable filter 39.

FIG. 3 is a longitudinal sectional view showing another example of the structure of the filter 39 in FIG. In the filter of FIG. 3, the connector 41 is formed by joints 43 and 44 that are removably connected (in the illustrated example, screwed),
The structure is such that the filter element 42 is sandwiched between these joints 43 and 44. FIG. 3(A) shows the state in use, and FIG. 3(B) shows the state at the time of replacement. According to the filter 39 of FIG. 3, the joints 43, 4
4 can be removed and only the filter element 42 can be replaced, resulting in cost savings.

According to the embodiment described above, a replaceable filter 39 is provided between the ink storage section (ink tank) 4 of the ink supply system and the recording means (recording head) 1; It is placed closer to recording means 1,
In addition, since two filters are installed, including the fixed filter 38 whose mesh is finer than that of the replaceable filter 39, it is possible to reliably prevent dust from entering the liquid path 29 and the ejection port 30 of the recording means 1, and to prevent ink from entering. An inkjet recording device capable of periodically removing dust from the supply system was obtained.

In the above embodiment, a serial type inkjet recording apparatus in which a recording means (recording head) 1 is mounted on a carriage 2 that moves along a recording material,
Although the present invention has been described as an example of a case where the present invention is applied, the present invention is applicable to a line-type inkjet recording device that uses a line recording means having a length corresponding to the whole or part of the widthwise recording area of a recording material, etc. , regardless of the type of scanning method, can be applied in the same way and can achieve similar effects.

Furthermore, in the above embodiments, the case of a color inkjet recording apparatus equipped with a plurality of recording means (recording heads) 1 for recording in different colors was exemplified.
The present invention is equally applicable regardless of the number of recording means, such as an inkjet recording device that records with one recording means, or an inkjet recording device for gradation recording that uses multiple recording means with the same color but different density. It is possible to achieve similar effects.

The present invention can be applied to any inkjet recording device that uses a recording means (recording head) using an electromechanical transducer such as a piezo element. This provides excellent effects in the proposed bubble jet type inkjet recording apparatus. This is because, according to such a system, higher recording density and higher definition can be achieved.

For its typical configuration and principle, see, for example, US Pat. Nos. 4,723,129 and 4,740.
Preferably, this is done using the basic principles disclosed in the '796 specification. This method can be applied to both the so-called on-demand type and continuous type, but
In particular, in the case of the on-demand type, the electrothermal transducer placed corresponding to the sheet holding the liquid (ink) or the liquid path is required to respond to the recorded information and rapidly exceed nucleate boiling. By applying at least one drive signal that causes a temperature increase, the electrothermal transducer generates thermal energy that causes film boiling on the heat-active surface of the recording means (recording head), resulting in a pair of It is effective because it can form bubbles in the liquid (ink).

The growth and contraction of the bubble causes liquid (ink) to be ejected through the ejection opening to form at least one drop. It is more preferable to use this drive signal in a pulse form, since the growth and contraction of bubbles can be carried out immediately and appropriately, so that ejection of liquid (ink) with particularly excellent responsiveness can be achieved. This pulse-shaped drive signal is described in US Pat.
Those described in Japanese Patent No. 463359 and Japanese Patent No. 4345262 are suitable. Incidentally, US Pat.
If the conditions described in No. 24 are adopted, even more excellent recording can be achieved.

In addition to the configuration of the recording head, which is a combination of ejection ports, liquid paths, and electrothermal converters (straight liquid flow path or right-angled liquid flow path) as disclosed in the above-mentioned specifications, U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4 disclose a configuration in which a heat acting part is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Patent Application Laid-open No. 123670 of 1982 discloses a configuration in which a common slit is used as a discharge part for a plurality of electrothermal converters, and a hole that absorbs pressure waves of thermal energy is disclosed. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 138461 of 1981, which discloses a configuration in which a discharge portion corresponds to a discharge portion. That is, regardless of the form of the recording head, according to the present invention, recording can be performed reliably and efficiently.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by a recording apparatus. Such a recording head may have a configuration in which the length is satisfied by a combination of a plurality of recording heads, or a configuration as a single recording head formed integrally.

In addition, even in the case of a serial type as in the above example, the recording head is fixed to the main body of the apparatus, or by being attached to the main body of the apparatus, electrical connection with the main body of the apparatus and ink flow from the main body of the apparatus are possible. The present invention is also effective when using a replaceable chip-type recording head that can be supplied with ink or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus, to the present invention because the effects of the present invention can be further stabilized. Specifically, these are:
Capping means, cleaning means, pressure or suction means, preheating means using an electrothermal transducer or another heating element, or a combination thereof, and ejection other than recording for the recording head. It is also effective to perform a preliminary ejection mode to perform stable printing.

Regarding the type or number of recording heads to be mounted, for example, in addition to a single head installed to handle a single color ink, a head that can handle multiple inks with different recording colors or densities may be used. A plurality of them may be provided. That is, for example, the recording mode of the recording device is not only a recording mode for mainstream colors such as black, but also a recording mode for only mainstream colors such as black.
The recording head may be configured integrally or in combination, but the present invention is also extremely effective for devices equipped with at least one of multiple colors of different colors or full color by mixing colors.

In addition, in the embodiments of the present invention described above, the ink is described as a liquid, but ink that solidifies at room temperature or below, softens or liquefies at room temperature, or ink jet In this method, the temperature of the ink itself is generally adjusted within the range of 30°C to 70°C to keep the viscosity of the ink within the stable ejection range. Any liquid may be used.

In addition, the temperature increase caused by thermal energy can be actively prevented by using it as energy for changing the state of the ink from a solid state to a liquid state, or the ink can be left to solidify in order to prevent evaporation. In any case, the ink is liquefied by applying thermal energy in accordance with the recording signal, and the liquid ink is ejected, or the ink already begins to solidify by the time it reaches the recording medium. The present invention is also applicable when using ink that is liquefied only by thermal energy, such as.

[0042] The ink used in such a case is disclosed in Japanese Patent Application Laid-Open No. 1983-
56847 or Japanese Unexamined Patent Publication No. 60-71260, a form in which the porous sheet is held as a liquid or solid in the recesses or through holes and faces the electrothermal converter. You can also use it as

In the present invention, the most effective method for each of the above-mentioned inks is to implement the above-mentioned film boiling method.

In addition, the inkjet recording apparatus according to the present invention can be used as an image output terminal for information processing equipment such as a computer, a copying apparatus combined with a reader, etc., and a facsimile apparatus having a transmission/reception function. It may also take the form of

[0045]

As is clear from the above description, according to the present invention, in an inkjet recording apparatus that performs recording by ejecting ink from a recording means onto a recording material, the ink storage section of the ink supply system and the recording means can be connected to each other. In between, a replaceable filter and a fixed filter, which is placed closer to the recording means than the replaceable filter and has a finer mesh than the replaceable filter, are installed. An inkjet recording device is provided that can prevent dust from entering an outlet and can periodically remove dust within an ink supply system.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an ink supply system of an inkjet recording apparatus according to the present invention.

FIG. 2 is a longitudinal cross-sectional view of the replaceable filter in FIG. 1;

FIG. 3 is a longitudinal sectional view showing another structural example of the replaceable filter in FIG. 1;

FIG. 4 is a perspective view of an embodiment of an inkjet recording apparatus according to the present invention.

5 is a partially cutaway perspective view of the ink ejection section of the recording means in FIG. 4; FIG.

[Explanation of symbols]

1 Recording means (recording head) 2 Carriage 4 Ink storage section (ink tank) 5 Pump 6 Ink supply side channel (tube) 7
Ink return flow path (tube) 22 Electrothermal converter 27 Common liquid chamber 29 Liquid path 30 Discharge port 38 Fixed filter 39 Replaceable filter 41 Connector 42 Filter element

Claims (3)

[Claims] Claim 1: In an inkjet recording apparatus that performs recording by ejecting ink from a recording means onto a recording material, an ink storage part of an ink supply system and an ink storage part of an ink supply system are provided.
An inkjet recording apparatus characterized by being equipped with a replaceable filter and a fixed filter that is disposed closer to a recording means than the replaceable filter and has a finer mesh than the replaceable filter. 2. The recording means is an inkjet recording means that ejects ink using thermal energy, and is equipped with an electrothermal converter for generating thermal energy. The inkjet recording apparatus according to claim 1. 3. The recording means utilizes a state change caused by the growth of bubbles due to film boiling caused by the thermal energy applied by the electrothermal converter,
3. The inkjet recording apparatus according to claim 2, wherein ink is ejected from an ejection port.