JP3179912B2 - Ink jet device and method of using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet apparatus having a recording head in which a large number of ink discharge ports are arranged along the width direction of a recording sheet.

[0002]

2. Description of the Related Art A recording method using a non-impact type printer has attracted attention for office use and the like because noise generated during recording is so small as to be negligible. Among them, the ink jet recording method capable of high-speed recording and capable of recording without applying a special fixing process to so-called plain paper is an extremely effective method, and various methods have been proposed and commercialized. Has been

In such an ink jet recording method, recording is performed by causing small droplets of a recording liquid, so-called ink, to fly from an ejection port and adhere to recording paper.
There are several control methods for controlling the generation of droplets of the recording liquid and the flight direction of the droplets.
In this configuration, the ink is caused to fly from the fine ejection ports. Therefore, there is always a problem that the ejection openings are clogged as a fate of the device for ejecting ink from such minute ejection openings.

In view of the above, various measures have conventionally been taken to prevent clogging or to recover the flying property of ink in a device that has been stopped for a certain period of time. One example is described in JP-A-62-77941. This is because, in a serial printer that moves a carriage on which a small recording head is mounted in the width direction of recording paper and drives the recording head in the moving process to record on the recording paper, a pump suction type is provided at a home position of the carriage. It is provided with a suction device. Such a suction device has been invented and improved in a serial printer, and is in a state where it can be regarded as technically substantially established.

On the other hand, in recent years, in order to print at higher speed, an ink jet apparatus having a large array type recording head in which a large number of ink ejection ports are arranged over a length corresponding to the entire width direction of the recording paper has been completed. Requested. Needless to say, such a large array type recording head also has a problem of ink clogging or non-ejection, and various methods for improving the problem are being studied.

As one example, for example, Japanese Patent Publication No. Sho 63-3
As disclosed in Japanese Patent Publication No. 1390, while the cap is placed over the entire large array type recording head, the cleaning liquid is flowed into the cap or the ink is ejected from the ink discharging port, so that the ink discharging port is It is to wash.

[0007]

As described above, the method of cleaning the large array type recording head by covering it with a cap requires a large-scale apparatus because the cap is large.
In addition, the ink is wasted in order to fly the ink from all the ink ejection ports, thereby increasing the running cost.

[0008]

According to the first aspect of the present invention,
A plurality of recording heads in which ink discharge ports are arranged along the width direction of the recording paper, at a certain distance from the discharge port surface in the ink nozzle array direction are arranged the motor driving movement of depending on the arrangement direction In an ink jet apparatus having a reliability recovery mechanism in which a cap that is moved and covers a part of the ink ejection port array and a negative pressure generating unit is connected inside the cap, the cap is driven by cap driving means. Therefore, the suction port is brought into close contact with and separated from the discharge port surface, and performs a suction operation due to the generation of a negative pressure at the time of close contact.
A predetermined test recording pattern output by the recording head is read by a scanner, and is compared with data of the test recording pattern stored in advance, so that a detected ink discharge having a defect such as clogging or idle hit occurs. This was done in the exit area.

[0009]

[0010]

[0011]

[0012]

[Action] first aspect of the present invention, over the ink discharge port by moving in the direction of arrangement of the ink discharge ports by the motor drive the movable body cap problems such as clogging or idle driving is occurring, a negative pressure By driving the generating unit, it is possible to suck ink from the defective ink ejection port, and clogging is performed by comparing the test recording result read by the scanner with the test recording pattern by the collating means. It is possible to automatically know the ink discharge port where the ink is generated, and based on the result, the cap can be moved to a desired position together with the movable body by the driving means to suck out the ink, thereby greatly improving the operability. Can be done.

[0013]

[0014]

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes a recording head. The recording head 1 has a length corresponding to the maximum width of a sheet to be used, and is formed by joining a substrate 2 and a grooved plate 3, and the grooved plate 3 has an ink reservoir formed therein. Is connected to an ink supply tube 4 for supplying the ink. Further, at the front edge of the grooved plate 3, several hundred to several thousand ink ejection ports 5 having an opening dimension of several tens of μm are arranged in a line.

Next, the structure of the recording head 1 will be described. FIG. 5 is an enlarged front view of a part of the recording head 1, and FIG.
FIG. 7 is a vertical sectional side view taken along line AA in FIG. 5, and FIG. 7 is a horizontal sectional view taken along line BB in FIG. As shown in FIG. 6, a number of grooves 6 are formed in parallel on the lower surface of the grooved plate 3,
The ink discharge ports 5 are opened at the tips of these grooves 6. The grooved plate 3 is formed with an ink reservoir (not shown) to which a part of each groove 6 is connected. On the upper surface of the substrate 2, a heating resistance layer 7 located at the bottom of the groove 6 is provided.
In addition, electrodes 8, 9 for applying a voltage to these heat generating resistance layers 7 and a protective layer 10 are formed in a laminated state.
The protective layer 10 chemically and physically protects the heat-generating resistor layer 7 from the liquid (ink) to be used, and short-circuits the pair of electrodes 8 and 9 through the liquid, or
It is formed in order to prevent an electric leak between them. The heat generating portion 11 is located above the heat generating resistive layer 7 at the portion where the ends of the electrodes 8 and 9 are separated and opposed.

Thus, as shown in FIGS. 3 and 4, a suction device 12 is provided. The suction device 12 has a carriage 14 as a movable body slidably guided by a guide rod 13 erected along the ink discharge port 5 of the recording head 1, and the carriage 14 is orthogonal to the guide rod 13. Slider 1 slidably fitted in direction
5, a cap 16 formed of an elastic member and fixed to the tip of a slider 15, an ink absorbing roller 17 rotatably held on both sides of the cap 16 and contacting the front edge of the recording head 1, 18, a tube joint 19 connected to the rear end of the slider 15, and a contact / separation mechanism 20 for bringing the slider 15 into and out of contact with the ink discharge port 5. The contact / separation mechanism 20 includes a carriage 14
And a connecting rod 23 connecting the plunger 22 and the tube joint 19 of the solenoid 21. The inside of the slider 15 and the cap 16 is formed in a hollow shape, and is connected to a negative pressure generating unit (not shown) via the tube joint 19 and the tube 24. The ink absorbing rollers 17 and 18 are made of an elastic material that easily absorbs liquid like a sponge. The width of the cap 16 is set to a narrow width corresponding to a part of the ink discharge ports 5.

Further, as shown in FIGS. 1 and 2, a drive mechanism 25 for reciprocatingly driving the suction device 12 along the recording head 1 is provided. This drive mechanism 25
A screw rod 26 to which the carriage 14 is screwed, and a forward / reverse rotatable motor 27 to which one end of the screw rod 26 is connected.
And As shown in FIG. 2, a mark 28 is formed on the upper surface of the carriage 14 as identification means located on a vertical line passing through the center of the cap 16.

In such a configuration, after the recording paper is supplied to the leading edge of the recording head 1, any of the
The recording is performed by causing the ink to fly from above and causing the ink droplets to adhere to the recording paper. The principle of flying the ink in this embodiment is that a voltage is applied to the heating resistance layer 7 via the electrodes 8 and 9, bubbles are generated in the ink by the heat generated in the heat generating section 11, and the internal pressure due to the expansion of the bubbles is increased. Is a thermal ink jet system in which ink is caused to fly by the rise of the temperature.

Here, a method of using the above-described ink jet apparatus will be described. By observing the result of flying the ink from all the ink discharge ports 5 on the recording paper, it is possible to inspect the ink discharge ports 5 in which a problem such as clogging or idle hit occurs. If a problem occurs, the motor 27 is driven to move the carriage 14 so that the mark 28 is positioned with respect to the corresponding ink discharge port 5, and the cap 16 is moved by the suction action of the solenoid 21. To drive the negative pressure generator. As a result, the defective ink ejection port 5
It is possible to suck ink from the printer. in this way,
Since the cap 16 can be moved together with the carriage 14 while viewing the mark 28 from the outside, it is possible to easily position the cap 16 with respect to the ink discharge port 5 in a portion where a problem has occurred. In addition, as the carriage 14 moves, ink and foreign matters adhering to the leading edge of the recording head 1 are wiped by the ink absorbing rollers 17 and 18.

As described above, by sucking ink only from some of the ink ejection ports 5 where a problem has occurred,
In order to reduce the size of the cap 16 and reduce the suction force of the negative pressure generating portion, and to recover from problems such as clogging of the ink discharge ports 5, ink from all the ink discharge ports 5 is conventionally used. Ink consumption can be significantly reduced as compared with the method of sucking ink. Thereby, initial cost and running cost can be reduced.

Although the recording head 1 of the thermal ink jet system has been described in the above embodiment, the present invention is not limited to this. For example, a piezoelectric element is used as a driving force for ink ejection, such as a Gould system described in US Pat. No. 3,683,212 (hereinafter referred to as USP), a stem system described in US Pat. The present invention is also applied to a drop-on-demand type recording head to be used. Also, USP 3,596,275
No. 3,298,030, a charge control type recording head known as a sweet type can be suitably used when a large number of nozzles are arranged to form a large array type. Further, the present invention can be applied to a recording head of an electrostatic suction type known as a teletype system described in US Pat. No. 3,060,429, and a recording head known as a Hearts type described in US Pat. No. 3,416,153.

Further, in the present embodiment, a so-called edge shooter type in which ink is jetted in a direction substantially parallel to the heating resistor layer 7 has been described as an example.
As described in Japanese Patent Application Laid-Open No. 95156, the present invention can be applied to a so-called side shooter type recording head that causes ink to fly in a direction substantially perpendicular to the heat generating resistance layer.

Further, as shown in FIG.
The present invention is also applicable to a large array type recording head 1 in which grooved plates 3 each having a limited number of ink discharge ports 5 are alternately arranged on both sides in a staggered manner. Of course, the present invention can be applied to a color printer using a plurality of print heads including the print head 1 of the present embodiment for each of yellow, magenta, cyan, and black. .

Next, another embodiment of the present invention will be described with reference to FIG. The same parts as those in the above embodiment are denoted by the same reference numerals, and the description is omitted. The printer body 29 includes the recording head 1, the suction device 12, a transport unit 31 that supplies roll paper 30 to the recording head 1, and a transport unit that supplies cut paper 32 in a paper cassette to the recording head 1. 33 are provided. A cutter 34 for cutting the roll paper 30 is provided in the transport path of the roll paper 30. Further, a platen roller 35 and a pressing roller 36 that hold the supplied roll paper 30 or cut paper 32 in a tensioned state and face the recording head 1 are provided above and below the recording head 1.

Further, the printer body 29 has a storage means (not shown) in which a fixed test recording pattern output by the recording head 1 is stored, and an image recorded based on the test recording pattern is optically stored. A collating unit (not shown) for comparing the read result of the scanner 37 with the test recording pattern to detect the ink ejection port 5 in which a defect such as clogging or blanking occurs. A driving mechanism 25 is provided as driving means for driving the carriage (movable body) 14 to an arbitrary position of the recording head 1 based on the result of the collation by the collating means.

In such a configuration, the test recording pattern stored in the storage means is output by the recording head 1 before recording. Subsequently, the result of the test recording read by the scanner 37 and output from the CCD image sensor is collated with the test recording pattern stored in the storage unit by the collation unit. Exit 5 is automatically recognized. Based on the result, the driving means moves the cap 16 together with the carriage 14 to a desired position, and ink is sucked out according to the above-described operation. Therefore, operability can be significantly improved.

[0028]

According to the first aspect of the present invention, as described above,
A movable body with a cap that covers a part of the ink ejection ports
Slidable I along the direction of arrangement of the ink discharge ports by the motor drive, since the connected negative pressure generating portion in the interior of the cap, the cap is moved together with the movable member occurs problems such as clogging or ineffective by By driving the negative pressure generating unit over the ink ejection port that is being operated, the ink can be sucked out from the ink ejection port where the problem has occurred, and therefore, the quality of the recorded image can be improved. By sucking ink only from a part of the ink ejection ports where a problem has occurred, the cap can be downsized, the suction force of the negative pressure generating section can be reduced, and clogging of the ink ejection ports can be recovered. In this case, the consumption of ink can be significantly reduced, thereby reducing the initial cost and running cost. Thus, a storage unit in which a certain test recording pattern output is stored, a scanner that optically reads an image recorded based on the test recording pattern, and a result read by the scanner and the test recording pattern are compared. Collating means for detecting an ink ejection port having a problem such as clogging or idling, and driving means for driving a movable body to an arbitrary position of the recording head based on a collation result of the collating means. Therefore, by collating the test recording result read by the scanner with the test recording pattern by the collating means, it is possible to automatically know the ink discharge port where clogging or the like has occurred, and based on the result, the driving means By moving the cap to the desired position together with the movable body, the ink can be sucked out, greatly improving operability. An effect such as can be.

[0029]

[0030]

[0031]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a perspective view showing a suction device.

FIG. 3 is a vertical sectional side view showing a suction device.

FIG. 4 is a horizontal sectional view showing a suction device.

FIG. 5 is an enlarged front view of a part of the recording head.

FIG. 6 is a vertical sectional side view taken along line AA in FIG. 5;

FIG. 7 is a horizontal sectional view taken along the line BB in FIG. 6;

FIG. 8 is a front view showing another example of the recording head.

FIG. 9 is a side view schematically showing a printer and a scanner according to another embodiment of the present invention .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head 5 Ink ejection port 14 Movable body 16 Cap 25 Driving means 28 Identification means 37 Scanner

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B41J 2/01 B41J 2/18 B41J 2/185

Claims (1)

(57) [Claims] And 1. A recording head having multiple ink ejection openings arranged along the width direction of the recording sheet, from the discharge port surface to the motor drive movement is arranged in the array direction depending on the arrangement direction of the ink discharge port In an inkjet apparatus having a reliability recovery mechanism that is moved at a fixed distance and covers a part of the ink ejection port array and a negative pressure generating unit is connected inside the cap, the cap is a cap.
By the driving unit , the suction port is brought into close contact with and separated from the discharge port surface, and performs a suction operation by generating a negative pressure at the time of close contact,
In the suction operation, a fixed test recording pattern output by the recording head is read by a scanner, and is compared with data of the test recording pattern stored in advance. An ink jet apparatus, which is performed in a generated ink ejection port area.