JPH06143548A - Ink jet recorder - Google Patents

Abstract

PURPOSE:To prevent an unnecessary recovering operation and effectively perform a recording operation by providing means for recovering a recording element as specified when discriminating means discriminates an ink discharge defective state. CONSTITUTION:Inks emitted from nozzles 6 of ink discharging units 4 of an ink jet head become dots on a record sheet. Resolutions of the dots (nozzles) are 360dpi, and the number of the nozzles on the units 4 are 64 (64 dots). Line sensors 8 are provided in parallel with the units 4 rear of a carriage advancing direction. Numeral 10 denotes a light-emitting unit to be read via an LED, etc., 12 is a photosensor, and 14 is bits of the photosensors. Resolution of the photosensor is 360dpi of the same as that of the unit 4, the photosensors are 64 bits, and the bits are disposed at positions corresponding to nozzles (dots) of the head.

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 which ejects ink to record an image.

[0002]

2. Description of the Related Art Conventionally, an ink jet type recording apparatus has been known. In these devices, the ink is inserted into the nozzles arranged corresponding to the head resolution, the heating elements provided in each nozzle are energized, and the ink is heated, so that the ink is ejected from the predetermined nozzles. A recording head is used which forms characters and images by ejecting the ink and fixing it onto recording paper.

One of the principles of ink ejection from nozzles in the ink jet system is as follows.

That is, when a nozzle filled with ink is rapidly heated, small bubbles in the nozzle are expanded and accumulated, and finally, the rapid expansion force pushes the ink out of the nozzle outlet to record an ink bullet. It is made to adhere to paper and recorded as one dot.

[0005]

However, in the case of the ink jet system having such a principle and structure, for example, when the ink is not used for a long time, the ink is vaporized and solidified in the nozzle, In addition, the paper dust of the recording paper gets into the vicinity of the nozzle ejection port and becomes clogged, and after that, ink cannot be ejected, or air bubbles abnormally occur in the nozzle for some reason and the nozzle is filled with air bubbles. However, a so-called ink non-ejection state may frequently occur, such as ink not ejecting even if the nozzle heats the heating element, and the head side cannot detect this non-ejection state. However, there are cases where ink is not ejecting at all even if you intend to.

For this reason, in such a recording apparatus using an ink jet head, in order to remove or prevent the non-ejection state, the recording is once interrupted even at the start of recording or during recording. It is necessary to periodically perform a so-called recovery operation, in which all the ink in all the nozzles is sucked by the pump device and the ink in the ink reservoir is newly circulated to the nozzles.

For this reason, even if there is no non-ejection nozzle, the recovery operation is performed to waste ink, and conversely, even if non-ejection occurs, the recovery operation is not performed until the next cycle. In some cases, printing was continued without ejection until the recovery operation.

Further, since the non-ejected dots cannot be detected, it is necessary to carry out the recovery operation over all the nozzles of the head.

The present invention has been made in view of the above points,
It is an object of the invention to provide an inkjet recording apparatus capable of preventing an unnecessary recovery operation and performing a reliable recording operation.

[0010]

In order to achieve this object, the present invention moves a print head in which a plurality of print elements for ejecting ink are arranged relative to a print material to perform print scanning. In an ink jet recording apparatus for performing, a reading unit arranged behind the plurality of recording elements with respect to the recording scanning direction, and an ink ejection state by reading an image recorded by the plurality of recording elements by the reading element. And a recovery unit that performs a predetermined recovery process on the recording element by determining that the ink ejection failure state has occurred in the determination unit.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a front view of a casing of a recording head embodying the present invention. On the recording apparatus, a carriage on which the recording head is mounted advances toward the left to perform the recording apparatus. .

In this figure, 2 is the housing of this head,
Reference numeral 4 denotes an ink ejection portion of an ink jet head, and 6 denotes each nozzle (ejection port) of the head, and the ink ejected from each nozzle becomes each dot on the recording paper. In this embodiment, the resolution of each dot (nozzle) is 360 dpi, and the number of nozzles on the ink ejection unit 4 is 64 (64 dots).
In this embodiment, a heating element is provided corresponding to each nozzle, and the thermal energy generated from the heating element causes bubbles to be generated to change the state of the ink, thereby ejecting an ink droplet from the ejection port. To do.

Reference numeral 8 is a line sensor provided in parallel with the ink ejecting portion 4 and at the rear of the carriage advancing direction. Of these, 10 is an irradiation light emitting body for reading by an LED, 12 is a light receiving sensor portion, and 14 is a light emitting sensor portion. These are bits of the light receiving sensor. In the present embodiment, the resolution of the sensor unit 12 is 360 dpi, which is the same as that of the ink ejecting unit, and the light receiving sensor unit 12 has 6 bits.
4 bits, each bit is a nozzle (dot) of the head
Shall be in the position corresponding to.

Next, FIG. 2 shows an embodiment of a recording apparatus which carries out the recording operation by mounting the recording head with the line sensor shown in FIG.

The line sensor 20 shown in FIG. 1 is a recording head, of which 20a is a line sensor and 206 is an ink ejecting portion. 22 is a recording head with a line sensor 20
Carriage stand for mounting and moving during recording
Reference numeral 4 denotes a carriage drive for moving the carriage base 22 in accordance with recording characters and images, a control unit, 26 denotes a recovery operation control unit for controlling the recovery operation of the ink ejection unit 20b, and 2
Reference numeral 8 denotes an ink ejecting unit 20 according to a print character and an image during recording.
b, a head drive and control unit that drives and controls each nozzle (dot), 30 is a sensor output processing unit that processes the light reception output of the line sensor 20a, and 32 is a drive and irradiation light emitter (LED) of the line sensor 20a. , A sensor drive control unit for driving the light receiving sensor unit, 34 a paper feed drive control unit for feeding recording paper at the time of recording, 36 a CPU for controlling each of the above units, and 38 preset. Memory in which the control procedure of each part is programmed, 4
Reference numeral 0 is a character to be recorded or a character for generating an image according to the data sent from the host computer or the like, an image control unit, and 42 is an external interface unit for connecting to the host computer or the like.

The recording operation of the apparatus of this embodiment will be described below with reference to the flowchart of FIG. When the character code of the print character arrives at this device according to the print command from the host computer, the external interface unit 4
It is recognized by the CPU 36 via 2. This makes the CPU
Reference numeral 36 drives the carriage drive control unit 24 and the paper feed drive control unit 34 to move the recording paper and move the carriage base 22 to the recording / printing start position (STEP 1). After that, the CPU 36 causes the image control unit 40 to generate print dot information of the print character according to the character code of the print character, whereby the head drive control unit 28 drives the heating elements corresponding to the predetermined nozzles. While forming print dots on the recording paper, the carriage drive control unit 24
By moving the carriage base 22 by means of, the printed characters are formed (STEP 2).

During the above recording and printing operation, in the apparatus of this embodiment, the CPU 26 drives the line sensor section 20a by the sensor drive control section 32, and the sensor output processing section 30 causes the ink ejection section 20b to generate the print dots. Is monitored (STEP 3).

That is, the CPU 36 generates a print dot by driving the head drive control unit 28, and then determines the white or black of the sensor output bit corresponding to the dot previously generated by the output of the sensor output processing unit 30. Do (STE
P4).

If the sensor output bit corresponding to the print dot is black, it is assumed that the ink has been ejected normally and the print dot is formed, and the recording operation is continued (STEP 5). On the other hand, if the sensor output bit corresponding to the print dot is white (color of the recording paper), it is determined that the ink is not ejected, the number of times is counted, and the printing operation is immediately stopped (STEP 7).

Here, the CPU 36 causes the recovery operation control unit 26 to suck the ink in the nozzle of the ink ejection unit 20b,
The recovery operation is performed by circulating the ink (STEP 8).

After this, the CPU 36 restarts the printing operation again from the position where the printing operation was stopped, and at the same time, monitors the printing dots.

Here, if the print dot is black, it is assumed that the nozzle of the ink ejecting portion 20b has recovered to the normal state, and the printing operation is continued thereafter. However, if the ink is not ejected again, the above recovery operation is repeated.

If the normal state is restored after this, the printing operation is continued thereafter, but if the number of times of non-ejection of ink reaches a predetermined number (three times in this embodiment), at this time point. After that, the printing operation is terminated, and the CPU 36 displays "head error / ink shortage" on the display unit 44 (ST.
EP9).

By thus providing the line sensor for detecting the ink ejection or non-ejection of each nozzle in parallel with the ink ejection portion, the recovery operation is performed only when the non-ejection occurs, and the unnecessary recovery operation is prevented. When the ejection failure is repeated, it is possible to determine the ink exhaustion.

In the above embodiment, the recording head is described as an example in which the ink is ejected by causing a state change in the ink by using thermal energy, but the present invention is not limited to this, and the recording head is not limited to this. It can also be applied to a device that ejects ink by causing a state change in the ink using an electromechanical converter.

Further, as a form of the recording apparatus according to the present invention, in addition to the one provided integrally or separately as the image output terminal of the information processing equipment such as the word processor and the computer as described above, copying combined with a reader or the like is also possible. apparatus,
Further, it may take the form of a facsimile machine having a transmission / reception function.

[0027]

As described above, according to the present invention, the reading element is provided behind the plurality of recording elements in the recording scanning direction, and the image recorded by the plurality of recording elements is read by the reading element to form the ink. Since the ejection state is determined, it is possible to detect an ink ejection failure during the recording operation, and it is possible to perform a recovery process during recording as needed.

[Brief description of drawings]

FIG. 1 is a diagram showing a recording head used in a recording apparatus that is an embodiment of the present invention.

FIG. 2 is a block diagram of a recording apparatus of this embodiment.

FIG. 3 is a flowchart illustrating an operation of the recording apparatus according to the present exemplary embodiment.

[Explanation of symbols]

 2 head housing 4 ink discharge section 6 nozzle 8 line sensor 10 light emitter 12 light receiving sensor section 20 recording head 36 CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B41J 2/175 29/46 C 9113-2C 8306-2C B41J 3/04 102 Z

Claims (5)

[Claims] 1. An ink jet recording apparatus for performing a recording scan by moving a recording head, in which a plurality of recording elements for ejecting ink are arranged, relative to a recording material, wherein: A reading unit disposed behind the plurality of recording elements, a determination unit that determines an ink ejection state by reading an image recorded by the plurality of recording elements by the reading element, and the determination unit An inkjet recording apparatus, comprising: a recovery unit that performs a predetermined recovery process on the recording element by determining a defective ejection state. 2. The ink jet recording apparatus according to claim 1, wherein the recording head has the plurality of recording elements and the reading unit integrally formed. 3. The ink jet recording apparatus according to claim 2, wherein the reading unit has a light emitting element that irradiates the image and a light receiving element that receives light from the image. 4. The ink jet recording apparatus according to claim 3, wherein the light receiving element has the same resolution as the recording element. 5. The recording element generates heat energy,
The ink jet recording apparatus according to claim 1, wherein an ink droplet is ejected from an ejection port by causing a state change in the ink by the thermal energy.