JPH07304183A - Ink jet recording device - Google Patents

Abstract

PURPOSE:To provide an ink jet recording device wherein cleaning can be done in accordance with degree of stain of a face, defective images can be prevented, and stable excellent recording can be done for a long time. CONSTITUTION:A detecting means 3 is provided for detecting stains on a face 2 near a discharge opening of a record head 1. A cleaning means is provided for cleaning the face 2 near the discharge opening in accordance with the stains detected by the stain detecting means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording on a recording material by ejecting ink from a recording head.

[0002]

2. Description of the Related Art A recording device such as a printer, a copying machine, a facsimile or the like, or a recording device used as an output device such as a computer, a word processor, a workstation or the like, is printed on a sheet or a plastic thin plate (OHP sheet) based on image information. An image (including characters and symbols) is recorded on a recording material (recording medium). This recording device can be classified into an ink jet type, a wire dot type, a heat sensitive type, a thermal transfer type, a laser beam type, etc. depending on the recording system of the recording means used.

A serial type recording apparatus employs a recording method in which main scanning is performed in a direction intersecting a conveyance direction (sub-scanning direction) of a recording material. After setting the recording material at the specified recording position, move along the recording material (main scanning)
An image including characters and symbols is recorded by a recording unit (recording head) mounted on the carriage, and a predetermined amount of paper feed (sub-scanning) is performed after the recording for one line is completed. After that, by repeating the operation of recording (main scanning) the image of the next row, the image is recorded in the desired range of the recording material.

On the other hand, in a line type recording apparatus which records a recording material only in a sub-scanning direction in which the recording material is fed in the conveying direction, the recording material is set at a predetermined recording position, and recording for one line is continuously performed at once. Predetermined amount of paper feed while performing (pitch feed)
Then, the image is recorded on the entire recording material.

Among them, the ink jet type (ink jet recording apparatus) is one in which ink is ejected from a recording head onto a recording material to perform recording, the recording head can be easily made compact, and a highly precise image can be formed at high speed. It is possible to record on plain paper without requiring special treatment, low running cost, less noise due to non-impact method, and color images can be printed using multi-color ink. It has advantages such as being easy to record.

Particularly, an ink jet type recording head for ejecting ink by utilizing thermal energy is
After undergoing semiconductor manufacturing processes such as vapor deposition and sputtering,
By forming a film-formed electrothermal converter, an electrode, a liquid passage wall, a top plate, etc. on a substrate, it is possible to easily manufacture a product having a high-density liquid passage arrangement (nozzle arrangement). Can be made more compact. Further, by taking advantage of the IC technology and the micro processing technology, it is easy to make the printing apparatus long and planar (two-dimensional), and it is also easy to make the printing apparatus multi-dimensional and high-density mounting.

In the above-mentioned ink jet recording apparatus, since ink (recording liquid) is directly ejected from the recording head to perform recording, it is necessary to always keep the ink in an ejectable state.
Therefore, special consideration not found in other recording devices is required. For example, if paper dust, dust, thickened ink, or ink droplets adheres to the face surface (the surface where the ejection ports are provided) of the recording head, the foreign matter is affected by these foreign matters,
As a result, defective image quality such as non-ejection and deviation of the recorded image may occur.

Therefore, in order to solve the above problems, in order to clean the face surface of the recording head, a flexible blade is provided facing the recording head and the face surface of the recording head is wiped off. Alternatively, a method is adopted in which a porous body having water absorbability is provided and excess ink on the face surface is absorbed.

In addition, cleaning with a flexible blade during printing predicts in advance how long or the number of dots the ejection failure and the misalignment caused by the adhesion of foreign matter such as unnecessary ink, dust or thickened ink will occur in advance. However, the wiping timing is often controlled by a timer and a dot counter that counts the number of dots.

[0010]

However, since the cleaning with the flexible blade is performed at a constant cycle as in the conventional example, there are the following drawbacks.

(1) Despite the fact that not much unnecessary ink, dust, thickened ink, or the like is attached to the face surface of the recording head, cleaning is performed by the flexible blade, and the printing time is reduced accordingly. It will be long. Further, extra cleaning by the flexible blade is performed, which accelerates wear of the flexible blade and the face surface. (2) Especially when a high-density image is printed when a flexible blade is used for cleaning during printing, a large amount of unnecessary ink adheres before cleaning, which results in non-ejection and misalignment. Occurs. Further, when a low-density image is printed, only certain nozzles (ejection ports) are used, and unnecessary ink may adhere to the nozzles, resulting in non-ejection and twisting.

In order to solve the above-mentioned problems, it is an object of the present invention to enable cleaning depending on the degree of dirt on the face surface of the recording head, prevent image defects, and maintain good stability over a long period of time. An object of the present invention is to provide an ink jet recording apparatus that performs various recording.

[0013]

In order to achieve the above-mentioned object, the present invention provides an ink jet recording apparatus having a recording head for recording by ejecting ink from an ejection port,
An ink jet recording apparatus comprising: a stain detection unit that detects stains near the discharge port of the recording head; and a cleaning unit that cleans a surface near the discharge port by the stain detection by the stain detection unit.

According to another aspect of the present invention, the dirt detecting means is provided on the carriage which fixes the recording head and reciprocates in the main scanning direction, and has a photosensor in which a light emitting portion and a light receiving portion are integrated, and this photosensor. It is composed of a reflection plate provided so as to face the photo sensor.

According to still another aspect of the present invention, the dirt detecting means is provided so as to face the platen which regulates the recording surface of the recording material while keeping a minute gap with the discharge port, and the light emitting portion and the light emitting portion. And a light receiving section for directly receiving the emitted light.

According to still another aspect of the present invention, the dirt detecting means is provided on the platen so as to face the light emitting portion and the light receiving portion for receiving the light emitted from the light emitting portion by reflecting the light emitted from the light emitting portion near the ejection port. And a photo sensor.

[0017]

By adopting the ink jet recording apparatus of the present invention, a dirt detecting means for detecting dirt near the ejection opening of the recording head is provided, and the surface near the ejection opening is cleaned by the dirt detection by the dirt detecting means. By providing the means, it is possible to clean the face surface of the recording head depending on how dirty it is, prevent image defects, and perform stable and good recording for a long period of time.

[0018]

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

FIG. 4 is a schematic block diagram of an ink jet recording apparatus embodying the present invention. In the figure, recording head 1
The head cartridge (hereinafter referred to as a head cartridge) is a recording head chip (not shown) having an ejection energy generating element (for example, an electrothermal converter) provided at an ink ejection port (not shown).
And an ink tank (not shown), which is an ink supply source, are integrally configured. This head cartridge 1
Is fixed on the carriage 8 by a pressing member (fixing lever) 4 and extends along the shaft 5 in the longitudinal direction (main scanning direction).
It is reciprocally movable.

The ink ejected from the ejection port of the head cartridge 1 reaches a platen 6 which is arranged at a minute distance from the ejection port and reaches a recording material (recording paper) (not shown) whose recording surface is regulated. Then, an image is formed on the recording paper.

An electrothermal converter (not shown) provided on the recording head chip receives an ejection signal from an appropriate data source via a cable 7 and a terminal connected to the cable 7 in accordance with image data. Supplied.

The blade 9 of this embodiment, which is a cleaning means,
The head cartridge 1 is arranged so as to project toward the head cartridge 1 and face each other, and if necessary, the head cartridge 1 is moved in the main scanning direction to clean (wiping) the face surface 2 (FIG. 1) provided with ejection openings (not shown). It is a thing. By this wiping, foreign substances such as ink leakage and paper stains attached to the face surface 2 are removed. The blade 9 has flexibility and is preferably made of a material having excellent wear resistance, chemical resistance, and ink wettability, and is preferably a polyurethane rubber plate or the like.

FIG. 1 is a schematic block diagram of an embodiment of the present invention. In the figure, the head cartridge 1 has a fixed lever 4
It is fixed on the carriage 8 by. Further, a face surface 2 is arranged between the dirt detection sensor, which is a photo sensor in this embodiment, a photo interrupter 3 and the reflection plate 10 on the carriage 8. The photo interrupter 3 has a light emitting unit and a light receiving unit integrated with each other, and when the head cartridge 1 returns to the line end, which is the print start position, every time one line prints, the face surface 2 of the head cartridge 1 is printed. The dirt a (FIG. 2 (B)) is detected.

As shown in FIG. 2, the light L0 emitted from the light emitting portion of the photo interrupter 1 provided on the carriage 8 is
Similarly, the light is reflected by the reflection plate 10 provided in the head cartridge 1 and received by the light receiving portion of the photo interrupter 3 as light L1 (FIG. 2A).

When the foreign matter a is attached to the face surface 2, the light emission L0 from the light emitting portion is absorbed or blocked by the foreign matter a and thus does not reach the reflection plate 10 (FIG. 2).
(B)). Therefore, the light is not received by the light receiving portion of the photo interrupter 3. This light emission L0 is about 0.3mm from the face 2
If it is cut off for more than a certain degree, it is judged that there is a foreign substance a,
The wiping operation is set to remove the foreign matter a adhering to the face surface 2, and image defects such as ink leakage, non-ejection, and twisting are prevented.

FIG. 3 shows a block diagram of the control operation circuit of FIG. In the figure, the control unit 11 outputs a control signal to the drive motor 12, starts driving and records an image, detects the dirt a on the face surface 2 with the photo interrupter 3, and the drive motor 12 causes the head cartridge 1 to move the blade 9 to the blade 9. Then, the control operation is performed so as to perform wiping.

FIG. 5 shows a schematic block diagram of another embodiment of the present invention. In the figure, parts having the same functions as in FIG.
The same reference numerals are attached. In the inkjet recording apparatus, the head cartridge 1 is moved to a position where dirt (foreign matter) a on the face surface 2 can be detected. The photo interrupter light emitting unit 13 of the present invention, which is a photo sensor, and the photo interrupter light receiving unit 14 (FIG. 6) are provided on the platen 6.
And are arranged to face each other. When the head cartridge 1 returns to the line end, which is the print start position, for each line printing, the photo interrupters 13 and 14 can detect stains on the face surface 2. Incidentally, P is a recording paper on the platen 6.

As shown in FIG. 6A, when the foreign matter a is not attached to the face surface 2, the light emission L0 of the photo interrupter light emitting section 13 is received by the interrupter light receiving section 14. However, as shown in FIG. 6 (B), when the foreign matter a adheres to the face surface 2, the light emission of the interrupter light emitting section 13 occurs.
The L0 is absorbed or blocked by the foreign substance a and is not received by the interrupter light receiving unit 14.

Therefore, when the light emission L0 of the interrupter light emitting portion 13 is blocked by the foreign matter a of 0.3 mm or more from the face surface 2, the blade 9 performs the wapping to remove the foreign matter a on the face surface 2. is there. This detection is performed before the start of printing, and therefore image defects are prevented.

FIG. 7 is a schematic block diagram of still another embodiment of the present invention. In the figure, parts having the same functions as those in FIGS. 1 and 5 are designated by the same reference numerals. In the inkjet recording apparatus, the head cartridge 1 is moved to a position where the foreign substance a on the face surface 2 can be detected. On the platen 6, a photo sensor light emitting portion 15 and a photo sensor light receiving portion 16 (FIG. 8) are arranged so as to face each other. When the head cartridge 1 is moved to the position shown in FIG. 7 before the start of printing, the photosensor light emitting unit 15 and the photosensor light receiving unit 16 can detect dirt (foreign matter) a on the face surface 2.

FIG. 8 is an enlarged side view of the head cartridge at the position where dirt can be detected on the face surface of FIG. In the figure, the light emission L0 from the photosensor light emitting section 15 is reflected by the face surface 2 of the head cartridge 1 and received by the photosensor light receiving section 16 as light reception L1. It should be noted that the face surface 2 is formed white in this embodiment so as to improve the reflection of light.

As shown in FIG. 8 (A), when the face surface 2 has no stain a, the photosensor light emitting portion 15 and the light receiving portion 1
6 is disposed at a position where maximum output is exhibited.
Further, as shown in FIG. 8B, when a foreign substance a is present on the face surface 2, the photosensor light receiving unit 16 does not receive the light.
Therefore, the presence / absence of the foreign substance a is detected based on the presence / absence of the output signal of the photosensor light receiving unit 16.

When the adherence of the foreign matter a on the face surface 2 is detected, wiping is performed to remove the foreign matter a and image defects are prevented. In order to improve the reflection, the face surface 2 is white in the present embodiment, but is not limited to this. For example, gold or silver may be used.

The present invention is not limited to the above embodiments, but can be implemented in other modes by making appropriate design changes.

[0035]

As is apparent from the above description, the ink jet recording apparatus of the present invention is provided with the dirt detecting means for detecting the dirt near the discharge port of the recording head, and the dirt detecting means detects dirt to discharge the ink. By providing a cleaning means for cleaning the surface near the outlet, the problems of the prior art can be easily solved, cleaning can be performed according to the degree of dirt on the face surface, image defects can be prevented, and long-term Stable and good recording is performed over the entire range.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

2A and 2B are explanatory diagrams of a stain detection operation state of FIG. 1, in which FIG. 2A shows a state in which no stain is detected, and FIG. 2B shows a stain detection state.

3 is a block diagram of the control operation circuit of FIG. 1. FIG.

FIG. 4 is a schematic configuration diagram of an inkjet recording apparatus in which the present invention is implemented.

FIG. 5 is a schematic configuration diagram of another embodiment of the present invention.

FIG. 6 is a diagram for explaining a stain detection state of FIG. 5, and FIG.
Indicates a state in which dirt is not detected, and FIG.

FIG. 7 is a schematic configuration diagram of still another embodiment of the present invention.

FIG. 8 shows an explanatory view of a dirt detection state of FIG. 7, and FIG.
Indicates a state in which dirt is not detected, and FIG.

[Explanation of symbols]

 1 Head Cartridge 2 Face Surface 3 Photointerrupter 5 Shaft 6 Platen 8 Carriage 9 Blade 10 Reflector 13 Photointerrupter Light Emitting Section 14 Photointerrupter Light Receiving Section 15 Photo Sensor Light Emitting Section 16 Photo Sensor Light Receiving Section a Foreign Material P Recording Paper

Claims (4)

[Claims] 1. An ink jet recording apparatus having a recording head for recording by ejecting ink from an ejection port,
An ink jet recording apparatus comprising: a stain detection unit that detects stains near the discharge port of the recording head; and a cleaning unit that cleans a surface near the discharge port by the stain detection by the stain detection unit. 2. The photodetector according to claim 1, wherein the dirt detection unit is provided on a carriage that fixes a recording head and reciprocates in the main scanning direction, and has a photosensor having a light emitting unit and a light receiving unit that are integrated with each other. An ink jet recording apparatus comprising a reflection plate provided so as to face a sensor. 3. The stain detecting means according to claim 1, wherein the stain detecting means is provided so as to face a platen which regulates a recording surface of a recording material while maintaining a minute gap with the discharge port, and the light emitting portion and the light emission of the light emitting portion. An ink jet recording apparatus, which is a photosensor comprising a light receiving section for directly receiving light. 4. The dirt detecting means according to claim 1, wherein the dirt detecting means is provided on the platen so as to face each other, and a light emitting part and a light receiving part for receiving the light emitted from the light emitting part by reflecting the light emitted from the surface near the ejection port. An inkjet recording apparatus, which is a photosensor including the following.