JPH09136431A - Ink-jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce costs of a recording apparatus more than when an ink emptiness and a nozzle clog are detected by separate sensors. SOLUTION: The apparatus has an ink empty detection sensor 16 for reading markings 50, 51 formed by blowing ink to a paper 6. The ink empty detection sensor 16 is shared between an ink empty detection means for detecting ink shortage from the marking 50 when the ink is empty and a clog detection means for detecting clog from the marking 51 when a nozzle clogs.

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 printing by ejecting ink onto a sheet.

[0002]

2. Description of the Related Art A communication device such as a facsimile device and an information processing device such as a personal computer usually include a recording device capable of printing data consisting of characters and figures as visual information so that the data can be printed on paper. Have. Various recording methods such as an impact method, a heat-sensitive method, and an ink-jet method are adopted for this recording apparatus. In recent years, an ink-jet method which is excellent in quietness and can print on paper of various materials is adopted. Ink-jet recording apparatuses are frequently used.

In the above-mentioned ink jet recording apparatus, an ink jet head having a large number of nozzles and a paper are arranged so as to face each other, and ink is ejected from the nozzles corresponding to output data and sprayed onto the paper while the ink jet head is main-scanned. According to this, characters and figures are printed on paper. Therefore, in the ink jet recording apparatus that prints by such an operation, quick drying is required for the ink so that the ink sprayed on the paper does not contaminate the area other than the sprayed portion, while high-definition print output is achieved. In addition, since the nozzle is required to have a small diameter, the nozzle is apt to be clogged due to the solidification of the ink.

Therefore, in the conventional ink jet recording apparatus, when the clogging is automatically detected, ink is sprayed from each nozzle onto the paper to form a marking,
By reading this marking with a sensor for detecting clogging, which is an optical sensor, clogging of the nozzle is detected.

[0005]

By the way, in the ink jet recording apparatus capable of automatically detecting clogging as in the above-mentioned conventional method, other processing operations are usually automated to improve operability and function. In addition to the clogging detection sensor, various sensors such as an ink empty detection sensor for detecting ink shortage and a paper shortage detection sensor for detecting paper shortage are configured. .

However, in the ink jet recording apparatus having the above-mentioned structure, the parts cost and the assembling cost are increased due to various sensors for improving the operability and the function. Therefore, it is highly desirable to reduce these sensors from the viewpoint of cost reduction, but if, for example, the clogging detection sensor is deleted, the clogging of the nozzle cannot be detected. This causes a problem that the function is deteriorated.

Therefore, the present invention is intended to provide an ink jet recording apparatus capable of reducing the number of sensors and reducing the cost without deteriorating the operability and the function.

[0008]

In order to solve the above-mentioned object, the invention of claim 1 has a sensor for reading a marking formed by spraying ink on a sheet, and the sensor is based on the marking. It is characterized in that it is commonly used as an ink shortage detecting means for detecting ink shortage and a clogging detecting means for detecting nozzle clogging based on the above marking. As a result, the detection of ink shortage and the detection of nozzle clogging are shared by one sensor, so it is possible to reduce the cost of the recording device compared to when each detection is performed by individual sensors. become.

According to a second aspect of the present invention, the clogging detection means of the first aspect forms ink by sequentially ejecting ink from each nozzle of the ink jet head to form markings, and the markings are sequentially read by the sensor.
The feature is that clogging of each nozzle is detected.
As a result, the clogging of each nozzle of the inkjet head can be individually detected using one sensor, so that it becomes possible to efficiently determine the head cleaning determination time after the clogging is detected. . further,
The invention of claim 3 is characterized in that the marking of claim 1 is formed on at least one of the left and right margins on the sheet. This makes it possible to detect clogging and ink shortage while printing output data other than marking.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a case where the present invention is applied to an ink jet recording apparatus of a facsimile machine.
This will be described below with reference to FIG.

The ink jet recording apparatus according to this embodiment is built in a facsimile machine as shown in FIG. The facsimile apparatus has an apparatus main body 1 having a lower cover 2 and an upper cover 3 serving as a housing, and a receiver 4 arranged on a side of the apparatus main body 1. The device body 1
As shown in FIG. 3, a document feeding device 21 that takes in the document 20 from above the upper cover 3 and then ejects it from the opening 3a, and an image reading device that reads an image of the document 20 conveyed by the document feeding device 21. 22 and a paper cassette 5 detachably provided from the front surface (left side surface in the drawing) of the lower cover 2.

The above-mentioned paper cassette 5 has a large number of papers 6
Are stacked and accommodated. These sheets 6 are urged upward at the front end side of the sheet cassette 5 located on the right side in the figure, and the uppermost sheet 6 is placed in the sheet cassette 5.
The sheet feeding roller 7 is provided in the vicinity of the sheet feeding port 5a.

The paper feed roller 7 is adapted to feed the paper 6 in the paper cassette 5 to the paper feeding device 8 from the paper feed port 5a. The paper feeding device 8 that feeds the paper 6 includes a paper leading edge detection sensor 11 that detects the leading edge of the paper 6, a curved paper guide 9 that regulates the feeding direction of the paper 6, and a paper feeding that feeds the paper 6. The paper 6 is conveyed by the paper feed roller 10 to the discharge roller 55 through the printing unit 12 by the paper feed roller 10. And the printing unit 1
From the position 2 to the unloading side of the paper 6, the paper guide 14 that regulates the traveling direction of the printed paper 6 and the paper 6 that is transported along the platen 13 and discharged to the outside by the discharge roller 55 is supported. The paper discharge table 15 is arranged in this order. The paper discharge table 15 also serves as a lid for the paper cassette 5.

The printing unit 12 has a platen 13 also serving as a chute mounted between the paper feed roller 10 and the discharge roller 55, and an ink jet recording apparatus main body 30 for spraying ink on the paper 6 for printing. doing. As shown in FIG. 1, the inkjet recording apparatus main body 30 includes an inkjet head 31 that ejects ink, a carriage 32 that is joined to the inkjet head 31, and a guide member that movably supports the carriage 32 in the main scanning direction X. 34a and 34b and the carriage 32 to the guide member 3
4a and 34b, and a traveling mechanism 33 that reciprocates (main scanning) in the main scanning direction X.

The above ink jet head 31 is shown in FIG.
As shown in FIG. 5, the piezoelectric element has a plurality of nozzles 31b ... Which eject ink by driving the piezoelectric element. Note that the inkjet head 31 may eject ink by a bubble method. The nozzles 31b ... Are arranged at regular intervals in the sub-scanning direction Y orthogonal to the main scanning direction X, and the nozzle numbers P (0) to P (N) can be individually specified. Is set.
The ink jet head 31 has the nozzle surface 31a formed with these nozzles 31b ... Faced so as to be parallel to the paper 6, and the ink ejected from each nozzle 31b. It is designed to spray vertically. As a result, as shown in FIG. 3, in the printing unit 12, the main scanning of the inkjet head 31 by the inkjet recording apparatus main body 30 and the sub-scanning of the paper 6 by the paper feed roller 10 are repeated, so that the paper 6 is scanned. Printing is performed by spraying ink on the entire surface or a part thereof.

On the side where the paper 6 is carried out from the printing section 12, a paper guide 14 that regulates the traveling direction of the printed paper 6 and a paper that is discharged along the paper guide 14 while being discharged outside the machine are provided. The paper discharge table 15 that supports the sheet 6 is arranged in this order. In addition, between the paper guide 14 and the discharge tray 15, the marking formed on the paper 6 is read to detect the ink shortage and the nozzle 31.
There is provided an ink emptyness detecting sensor 16 which is commonly used for detecting the clogging of b ... Instead of the ink emptyness detecting sensor 16, a clogging detecting sensor may be used.

The above-mentioned sensor for detecting emptyness 1
6 is connected to the sensor signal input unit 41, as shown in FIG. The sensor signal input unit 41 is connected to various sensors such as the above-described paper edge detection sensor 11 shown in FIG. Then, the sensor signal input unit 41 converts the signals from these sensors into a signal form suitable for information processing and outputs the signals to the control unit 40. A key input section 42 arranged on the front side of the upper cover 3 of FIG. 3 is connected to the control section 40. From the key input section 42, various kinds of numeric key data, function data, mode designation data, etc. Data will be input.

Further, the control unit 40 includes a head drive unit 4
3 and the display unit 44 are connected, and the head drive unit 4
3 is, when the output data is input from the control unit 40,
The drive voltage is applied to the nozzles 31b ... Of the nozzle number corresponding to the output data. The display unit 4
Reference numeral 4 denotes a liquid crystal display, which displays the control result and control contents on the screen based on the display data from the control unit 40.

The control unit 40 has an arithmetic unit and a storage unit (not shown). The storage unit includes an output data storage area for storing output data for one line when the inkjet head 31 is main-scanned, and a clogged nozzle 31.
Various data areas such as a nozzle data storage area for storing the nozzle number of b are formed. In addition, in the storage unit,
A clogging detection routine (clogging detection means) that detects clogging based on the marking 51 for clogging detection so that the apparatus body 1, the inkjet recording apparatus body 30, and the like perform various processing operations, and ink. A control program such as an ink shortage detection routine (ink shortage detection means) for detecting ink shortage based on the ink shortage detection marking 50 is stored.

In the above configuration, when a mode for detecting ink shortage is designated by a key operation on the key input unit 42, the ink shortage detection routine of FIG. 5 corresponding to this mode is executed.

That is, first, the output data for ink shortage detection is written in the output data storage area formed in the storage section of the control section 40. Thereafter, as shown in FIG. 3, the paper 6 is fed from the paper cassette 5 to the paper feeding device 8 and is conveyed by the paper feeding device 8 toward the printing unit 12. When the paper 6 reaches the predetermined position of the printing unit 12, the conveyance of the paper 6 is stopped, and then the inkjet head 31 is main-scanned by the traveling mechanism 33 as shown in FIG. The output data is output to the head drive unit 43. As a result, the nozzles 3 of the inkjet head 31 that are main-scanned
The drive voltage is applied to 1b ...
Ink is sprayed from the inkjet head 31 to the right margin portion of the sheet 6 that passes through the reading area, and a planar marking 50 for ink shortage detection is formed (S1).

Next, as shown in FIG. 3, the sheet 6 is sub-scanned by the platen 13 or the like, so that the sheet 6 is conveyed along the paper guide 14 onto the sheet discharge tray 15 (S2). ). At this time, the movement amount of the paper 6 is detected by a movement amount detecting means (not shown), and whether or not the marking 50 on the paper 6 has reached the reading position of the inkempty detection sensor 16 based on the movement amount. It will be determined (S3). When it is determined that the marking 50 has reached the reading position of the ink emptyness detecting sensor 16, as shown in FIG. 1, the marking 50 detected by the ink emptyness detecting sensor 16 is detected.
The density signal indicating the density of is acquired by the control unit 40 via the sensor signal input unit 41 (S4).

After that, the presence or absence of the marking 50 is determined by determining whether or not the density read by the ink emptyness detecting sensor 16 is equal to or higher than a predetermined density (S5). If it is determined that the marking 50 is not present, the data content indicating that the ink is out is output to the display unit 44 or the alarm is issued, and then the ink out detection routine is ended. (S6). On the other hand, if it is determined that the marking 50 is present, the data content indicating that ink is present is output to the display unit 44, and then the ink shortage detection routine is ended (S7).

Next, when a mode for detecting clogging is designated by a key operation in the key input section 42, the clogging detection routine of FIG. 6 corresponding to this mode is executed, and FIG. As shown, ink 51 is sequentially sprayed from the nozzles 31b of the inkjet head 31 to the right margin portion of the sheet 6 to form markings 51. The markings 51 ... Are sequentially read by the inkempty detection sensor 16. ,
The clogging of the nozzles 31b ... Is detected.

That is, first, after the nozzle number variable n is initialized (n = 0) (S11), as shown in FIG. 1, the nozzle of the nozzle number P (n) set by this nozzle number variable n is set. Output data for clogging detection is written in the output data storage area so that ink is ejected from 31b to form the marking 51. Thereafter, as shown in FIG. 3, the paper 6 is fed from the paper cassette 5 to the paper feeding device 8 and is conveyed by the paper feeding device 8 toward the printing unit 12. And paper 6
When the sheet reaches the predetermined position of the printing unit 12, after the conveyance of the sheet 6 is stopped, as shown in FIG. 1, while the inkjet head 31 is main-scanned by the traveling mechanism 33, the output data in the output data storage area is output to the head. It will be output to the drive unit 43. As a result, the drive voltage is applied to the nozzles 31b of the inkjet head 31 to be main-scanned at a predetermined timing, so that the sheet 6 that passes through the reading area of the ink empty detection sensor 16 is detected.
Ink is sprayed from the inkjet head 31 to the right margin portion of the line marking 5 for detecting clogging.
1 is formed (S12).

After that, "1" is added to the nozzle number variable n (S13), and then it is judged whether or not the nozzle number variable n matches the number N of nozzles of the ink jet head 31 (S14). If not, after the paper 6 is sub-scanned for one line (S15), the above-described S12 to S14 are re-executed. As a result, the nozzle number variable n
The markings 51 of the nozzles 31b ... Are formed on the paper 6 at intervals of one line by repeatedly executing S12 to S15 until the number of nozzles matches the number N of nozzles.

Next, in S14, the nozzle number variable n
When it is determined that the number of nozzles N matches the number of nozzles N, the nozzle number variable n is set to “0” (S16), and then the paper 6
Is sub-scanned (S17). At this time, the paper 6
Is detected by a moving amount detecting means (not shown), and the marking line on which the marking 51 of the nozzle number P (n) is formed based on the moving amount has reached the reading position of the ink emptyness detecting sensor 16. It will be determined whether or not (S18). When it is determined that the marking line has reached the reading position of the ink emptyness detecting sensor 16, the concentration signal detected by the ink emptyness detecting sensor 16 is detected by the sensor signal input unit 41.
By being sequentially captured by the control unit 40 via
The density of the marking line in the sub-scanning direction Y is continuously read (S19).

Thereafter, it is judged whether or not there is an area having a density equal to or higher than a predetermined density in the density read, and thus the marking 5 in the marking line of the nozzle number P (n)
The presence / absence of 1 is determined (S20). And
If it is determined that there is no marking 51, the nozzle 31b with the nozzle number P (n) is considered to be clogged, and the clogging process is performed. For example, the nozzle number P (n) is stored in the nozzle data storage area. At the same time, the fact that the display unit 44 is clogged is displayed together with the nozzle number P (n) (S21). Then, after "1" is added to the nozzle number variable n (S22), it is determined whether or not the nozzle number variable n matches the number N of nozzles of the inkjet head 31 (S23). On the other hand, in S20, when it is determined that the marking 51 does not exist,
The above S22 and S23 are directly executed.

When it is determined in S23 that the nozzle number variable n does not match the nozzle number N, the above-described S18 to S23 are re-executed, and the nozzle number variable n becomes the nozzle number N. It will be repeated until they match. As a result, all nozzle numbers P (0) to P (P)
After the presence or absence of the marking 51 of (N) is sequentially determined for each marking line, the clogging detection routine is ended.

The clogging detection routine of this embodiment is as follows.
After all the markings 51 ... Corresponding to the nozzle numbers P (0) to P (N) are formed, the presence or absence of clogging is determined. However, the present invention is not limited to this, and for example, an ink empty detection In consideration of the case where the use sensor 16 is provided immediately after the printing unit 12, the clogging may be detected while sequentially forming the markings 51.

Further, in the present embodiment, the key input unit 4
Although the ink out detection mode and the clogging detection mode are selected by the key operation in 2,
Each mode may be selected when a predetermined amount is printed. Further, in the present embodiment, the positions of the markings 50 and 51 are formed on the right margin portion of the paper 6, but the present invention is not limited to this, and it is sufficient that they are formed on at least one of the left and right margin portions. . further,
In this embodiment, the case where the invention is applied to a facsimile machine is described, but the invention is not limited to this, and can be applied to a printer device such as a personal computer.

[0032]

As described above, the invention according to claim 1 has a sensor for reading a marking formed by spraying ink on a sheet, and the sensor detects ink depletion based on the marking. The configuration is shared by the detection unit and the clogging detection unit that detects clogging of the nozzle based on the marking. As a result, the detection of ink shortage and the detection of nozzle clogging are shared by the sensor, so that it is possible to reduce the cost of the recording device as compared with the case where each detection is performed by an individual sensor. Play.

According to the invention of claim 2, as described above, the clogging detecting means of claim 1 sprays ink in order from each nozzle of the ink jet head to form a marking, and the marking is sequentially read by the sensor. By doing so, the clogging of each nozzle is detected. Accordingly, in addition to the effect of claim 1, clogging of each nozzle of the inkjet head can be individually detected by using one sensor.
It is possible to efficiently determine the timing for determining the head cleaning after detecting the clogging.

As described above, the invention of claim 3 is characterized in that the marking of claim 1 is formed on at least one of the left and right margins on the sheet. As a result, it is possible to detect clogging and ink shortage while printing output data other than marking.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a printing unit.

FIG. 2 is a perspective view of the facsimile machine.

FIG. 3 is a schematic configuration diagram of a vertical cross section of the facsimile apparatus as viewed from the side.

FIG. 4 is a perspective view of an inkjet head.

FIG. 5 is a flowchart of an ink shortage detection routine.

FIG. 6 is a flowchart of a clogging detection routine.

[Explanation of symbols]

 1 Device Main Body 4 Handset 5 Paper Cassette 6 Paper 7 Paper Feeding Roller 8 Paper Feeding Device 11 Paper Leading Edge Detection Sensor 12 Printing Section 13 Platen 16 Inempty Detection Sensor 21 Document Feeding Device 22 Image Reading Device 31 Inkjet Head 31a Nozzle Surface 31b Nozzle 33 Travel mechanism 41 Sensor signal input unit 42 Key input unit 43 Head drive unit 44 Display unit 50 Marking 51 Marking

Claims (3)

[Claims] 1. A sensor for reading a marking formed by spraying ink onto a sheet, the sensor detecting an ink depletion based on the marking, and a nozzle clogging based on the marking. An ink jet recording apparatus, which is also used as a clogging detecting means for detecting the. 2. The clogging detection means detects the clogging of each nozzle by sequentially spraying ink from each nozzle of the inkjet head to form a marking, and reading the marking in order by the sensor. The ink jet recording apparatus according to claim 1, which is characterized in that. 3. The ink jet recording apparatus according to claim 1, wherein the marking is formed on at least one of left and right margins on a sheet.