JPH0939269A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably and effectively detect the clogging of a discharge port by applying a record signal by different discharge frequencies near a plurality of ink discharge ports of a recording head, and deciding the state of the head based on the detection signal of each frequency. SOLUTION: A recording head 1 placed in a carriage 2 has a fin ink discharge port (orifice), liquid channel, an energy operating part provided at the part of the channel, and energy generating means such as electromechanical transducer such as a piezo element. The applied frequency of a pulse-shaped drive signal is set to different frequency at a plurality of ink discharge ports to differentiate the forming period of bubble in ink at each discharge port. In this case, a microphone 14 is disposed near the position where the head periodically so-called lost discharges to detect the ink discharge frequency, whether bubble is formed in the ink or not is judged, and the presence or absence of the ink at each ink discharge port or discharge failure is informed to a user based on the detected ink discharge frequency.

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, and more particularly to an ink jet recording apparatus using an ink jet recording system used in copying machines, printers, facsimiles and the like.

[0002]

2. Description of the Related Art Conventionally, various recording apparatuses for recording on a recording medium such as paper and OHP sheet have been proposed. Among them, a recording apparatus using an inkjet recording method is a recording head to a recording medium. Ink is directly ejected onto a recording medium for recording, and is attracting attention as an apparatus having advantages such as low running cost and quiet recording operation.

In an apparatus using such an ink jet recording method, ink is clogged in the ejection port of the recording head, so that the ejection amount of the ink does not change and the printing performance is not adversely affected. Ink clogging needs to be detected. As a conventional method for detecting this ink clogging, for example, as described in Japanese Utility Model Laid-Open No. 55-73348, a vibration sound of an inkjet recording head is detected using a microphone, and recording is performed by a change in the vibration sound. There is known a method of detecting clogging of ink in the head and notifying the user.

[0004]

However, in the above-mentioned conventional technique, when a plurality of types of ink are ejected by a recording head having a plurality of ink ejection ports, the main body of the apparatus does not clog the ejection ports of the ink jet recording head. Even if the detection and the notification are made, there is a drawback that it is not possible to determine which discharge port is clogged.

The present invention has been proposed in order to solve the above-mentioned drawbacks of the prior art, and its object is, in an ink jet recording head having a plurality of ink ejection ports, the presence or absence of ink or ejection abnormality in each ink ejection port. It is an object of the present invention to provide an inkjet recording device that can detect Another object of the present invention is to provide an ink jet recording apparatus capable of detecting the presence or absence of ink or ejection abnormality at each ink ejection port so that a good recorded image can be obtained during normal image recording.

Another object of the present invention is to provide an ink jet recording apparatus capable of detecting the presence / absence of ink in all ink ejection ports or the ejection abnormality in a short time. Another object of the present invention is to provide an inkjet recording apparatus capable of detecting an abnormal discharge of a target ink discharge port without mistakenly recognizing the abnormal discharge of another ink discharge port.

Another object of the present invention is to provide an ink jet recording apparatus which can detect the ink ejection frequency with a microphone. Another object of the present invention is to provide an inkjet recording apparatus capable of detecting the presence or absence of ink or abnormal discharge for each type of ink. Another object of the present invention is to provide an inkjet recording apparatus capable of detecting the presence or absence of ink or ejection abnormality for each ink even when recording an image with gradation or recording an image in color. .

[0008]

In order to solve the above problems and achieve the object, an ink jet recording apparatus according to the present invention has the following constitution. That is, in an ink jet recording apparatus equipped with a recording head having at least one ink tank and a plurality of ink ejection ports, ejection control means for applying a recording signal at different ejection frequencies near the respective ink ejection ports, and each ejection A frequency detecting means for detecting a frequency and a judging means for judging the state of the recording head based on a detection signal from the frequency detecting means are provided.

Further, preferably, the state of the recording head is a state of no ink in the ink tank or an abnormal state of ink ejection, and the judging means reports a state of no ink in the ink tank or an abnormal state of ink ejection. To do. Also,
Preferably, in the case of normal printing, all ejection ports are set to the same ejection frequency, and when detecting the state of the recording head, each ejection frequency is set to a different frequency.

Further, preferably, ink is ejected from the plurality of ink ejection ports at the same time, and the frequency detecting means simultaneously detects the absence of ink in the ink tank or the abnormal ejection state of the ink in the plurality of ejection ports. Further, it is preferable that the ejection frequencies are set so as to satisfy a "prime" relation, and the frequency detecting means simultaneously detects the absence of ink in the ink tank or the abnormal ink ejection state for a plurality of ejection ports. .

Further, preferably, the frequency detecting means is a microphone disposed near the ink ejection port. Further, preferably, a plurality of ink tanks are provided to store a plurality of inks, and a different ejection frequency is set for each ink ejection port corresponding to each ink. Further, preferably, the plurality of inks are single color inks having different densities or color inks having colors.

As described above, since the ink jet recording apparatus of the present invention is constructed, according to the invention of claim 1, the frequency detecting means detects different ejection frequencies for each ejection port, and By determining the state of the recording head based on the detection signal from the frequency detecting means, the state of the recording head can be determined for each ink ejection port. Also,
According to the second aspect of the present invention, it is possible to detect the state of no ink in the ink tank of the recording head or the abnormal ink ejection, and notify the user or the like.

According to the third aspect of the invention, in the case of normal printing, all ejection ports are set to the same ejection frequency, and when the state of the recording head is detected, each ejection frequency is set to a different frequency. Since the setting is made, it is possible to detect the presence or absence of ink or the ejection abnormality at each ink ejection port during normal image recording so that a good recording image can be obtained. Further, according to the invention described in claim 4, the ink is ejected from the plurality of ink ejection ports at the same time, and the frequency detecting means simultaneously detects the absence of ink in the ink tank or the abnormal ejection state of the ink from the plurality of ejection ports. Therefore, it is possible to detect the presence or absence of ink in all the ink ejection ports or the ejection abnormality in a short time.

Further, according to the invention described in claim 5, since the respective ejection frequencies are set so as to satisfy the relation of "prime to each other", the ejection abnormality of the noted ink ejection port of the other ink ejection ports is determined. The discharge abnormality can be detected without being mistaken for the discharge abnormality. Further, according to the invention as set forth in claim 6, since the microphone is arranged in the vicinity of the ink ejection port as the frequency detecting means, the microphone detects that there is no ink or ejection abnormality based on the output of different ejection frequencies of each ejection port. Can be detected.

Further, according to the invention described in claim 7, a plurality of ink tanks are provided for accommodating a plurality of inks, and different ejection frequencies are set for the respective ink ejection ports corresponding to the respective inks. No ink or ejection abnormality can be detected for each ink from the ejection frequency thus determined. Further, according to the invention of claim 8, the plurality of inks are single color inks having different densities or color inks having different colors. No ink or discharge abnormality can be detected for each color.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing a facsimile apparatus applied as an embodiment of the present invention. In FIG. 1, a portion indicated by a one-dot chain line A is a recording unit of an ink jet recording system, a one-dot chain line B is a reading unit for optically reading an original, a one-dot chain line C is a recording paper cassette, and a recording paper loaded in this cassette is 1
The sheet feeding unit separates the sheets one by one and supplies them to the recording unit A.

<Description of Device Main Body> In FIG. 1, a flow of a recording medium (hereinafter referred to as recording paper) will be briefly described. The conveying path of the recording paper is indicated by an arrow G. In the present embodiment, standard cut sheets are used, and a plurality of stacked sheets are stored in the recording paper cassette 50. The cassette 50 is attachable to and detachable from the main body 60, and in this embodiment, a universal cassette capable of accommodating fixed-size recording sheets of various sizes is used as the cassette 50.

The recording paper 12 stacked and stored in the recording paper cassette 50 is picked up by the paper feed roller 51 and the separation claw 52, and is conveyed by the conveying roller 53 and the conveying roller 53.
The paper is nipped and conveyed by the roller 54 which is arranged at a position facing and abutting against. The reversing guide 55 reverses the conveying direction of the recording paper 12, turns the recording paper 12 over, and conveys the U-turn.

In the recording unit A, recording is performed by the recording head 1, and on the downstream side of the recording head 1, a discharge roller 9 for conveying the printed recording paper 12 to the downstream side of the apparatus, and a discharge roller 9 A spur 8 made of a material that does not transfer ink even if it comes into contact with the printing surface of the recording paper 12 is provided on the opposite side of the spur 8. The rear guide 56 is formed with a plurality of ribs, is printed by the recording head 1, and regulates the lower part of the recording paper 12 that is ejected to guide the recording paper 12 along the conveyance path G.

Further, the spur 18 is made of the same material as that of the spur 8 and holds the recorded recording paper 12 together with the discharge roller 19 and is a cassette lid serving as a discharge rib 21 and a discharge tray provided on the main body 60. 22 is discharged and loaded.
Further, the cover 23 is configured to be openable and closable, and in the opened state, it becomes a space required for replacement of the recording head 1, etc.
A space is formed above the rear guide 56.

Next, the flow of the sheet material (hereinafter referred to as a document) will be described. In FIG. 1, a series of document feeding paths is indicated by an arrow F. Documents are placed on the document stack tray 3
When one or a plurality of sheets are set on 0, the presence thereof is detected by a document presence / absence sensor (not shown) for detecting the presence / absence of a document. Next, when the user presses a start button (not shown), the original is fed by the preliminary feeding roller 31 and the preliminary feeding pressing plate 32 which are rotatably driven by a stepping motor (not shown) as a driving source at the time of transmitting the original and copying. It is pinched and the tip is loosened.

After that, the original is transferred to the pre-transport roller 31 and
The separation roller 33, which is rotationally driven by the stepping motor, and the friction piece unit 34 are conveyed to the separation unit. When there are a plurality of originals, they are separated one by one, and are nipped and conveyed by a paper feed roller 35 that is rotationally driven by a stepping motor and a paper feed roller 36 that is arranged so as to face the paper feed roller 35. The leading edge of the document is detected by a document leading edge sensor (not shown) that detects the edge.

After that, while the document is being conveyed, the document sensor reads the document as image data, while the document leading and trailing edge sensor detects the trailing edge of the document, and the stepping motor rotates the document. When the paper output roller 38 is rotated by a predetermined amount at the time when the document front / back edge sensor detects the output, the paper output roller 38 and the paper output roller 39 arranged so as to face the paper output roller 38 are nipped and conveyed. , And is placed on the cover 23 which also serves as a document discharge tray.

Next, the detailed structure of the recording unit A of this embodiment will be described with reference to FIG. In FIG. 2, the recording unit A has a recording head 1, and the recording head of the present embodiment is a cartridge-type inkjet recording head that has a built-in ink tank and can be replaced with a new one when the ink is exhausted. is there. While the carriage 2 holds the position of the recording head 1 with high accuracy, the carriage 2 is reciprocated in a direction perpendicular to the conveyance direction (sub-scanning direction) of the recording paper 12, that is, in the main scanning direction, and is slid by the guide bar 11 and the abutting portion 2a. It is held movably. The reciprocating motion of the carriage 2 is
An image signal and power supplied to the recording head 1 at this time by a pulley 4 and a timing belt 3 driven by a motor (not shown) are supplied from an electric circuit of the main body by a flexible cable 7.

Further, the cap 15 functions as an ink receiving means, is installed at a position (home position) where the carriage 2 stands by, moves up and down as necessary, and when ascending, it comes into close contact with the recording head 1 and nozzles. The part is covered to prevent evaporation of ink and adhesion of dust. In this embodiment, in order to position the recording head 1 and the cap 15 so as to be relatively opposed to each other, the carriage home sensor 10 provided on the recording apparatus main body and the light shielding plate 2b provided on the carriage 2 are provided. Is used. The carriage home sensor 10 is composed of a transmissive photo interrupter, and when the carriage 2 moves to the standby position,
The fact that the light emitted from a part of the carriage home sensor 10 is blocked by the light shielding plate 2b is used to detect that the recording head 1 and the cap 15 are at positions relatively opposed to each other. is there.

The recording paper 12 is fed from the right side in FIG. 2, and is pressed in the direction indicated by an arrow H by a pressing roller 6 which is arranged facing the conveying roller 5 with a predetermined distance between the conveying roller 5 and a bearing member (not shown). It is conveyed in the (sub-scanning direction). The transport roller 5 and the paper discharge roller 9 are each driven by a drive system (not shown), and if necessary, interlock with the reciprocal movement of the carriage 2 to accurately transport the recording paper 12 in the sub-scanning direction. Further, the spur 8 is made of a material having high water repellency so as to be in contact with the recording paper 12 only by the recording paper surface and the blade-shaped circumferential portion. It is configured to guide and convey the recording paper 12 without affecting the image even if it contacts unfixed ink on the recording paper immediately after printing. The photo sensor 13 is provided to detect a jam of the recording paper.

The recording head 1 used in this embodiment is an ink jet type recording head and has a resolution of 360D.
The PI has 64 nozzles, and ejects ink from the ejection port at the tip of the nozzle by the pressure of film boiling generated in the ink by the heat generation of the electrothermal conversion element provided in the nozzle. <Description of Control Structure> Next, a control structure for executing the recording control of the above-described apparatus will be described.

FIG. 3 is a block diagram showing the arrangement of the control circuit of the recording unit in the facsimile apparatus of this embodiment. In the figure showing a control circuit, 1700 is an interface for inputting a recording signal, 1701 is an MPU, 1
Reference numeral 702 is a program ROM that stores a control program executed by the MPU 1701, and 1703 is a dynamic RAM that stores various types of data (the above-described recording signals and recording data supplied to the head). A gate array 1704 controls the supply of print data to the print head 1708, and includes an interface 1700 and MPU1.
Data transfer between the RAM 701 and the RAM 1703 is also controlled. 1
Reference numeral 710 is a carrier motor for carrying the recording head 1708, and 1709 is a carrying motor for carrying the recording paper. Reference numeral 1705 denotes a head driver for driving the head, 17
Reference numerals 06 and 1707 denote motor drivers for driving the carry motor 1709 and the carrier motor 1710, respectively.

The operation of the above control configuration will be described. When a recording signal enters the interface 1700, the gate array 17
04 and the MPU 1701 converts the recording signal into recording data for printing. Then, the motor driver 17
06 and 1707 are driven, and the head driver 1
The print head is driven according to the print data sent to 705, and printing is performed.

<Detailed Description of Recording Head> Next, the ejection principle of the recording head used in the ink jet recording apparatus of this embodiment will be described. A recording head applied to an inkjet recording apparatus generally applies a fine liquid ejection port (orifice), a liquid passage and an energy acting portion provided in a part of the liquid passage, and a liquid in the energy acting portion. It has an energy generating means for generating droplet forming energy and is replaceable.

As the energy generating means for generating such energy, an electromechanical converter such as a piezo element is used, and an electromagnetic wave such as a laser is radiated so that the liquid in the liquid absorbs it to generate heat. There is a method in which droplets are ejected and caused to fly by the action of, or a method in which the liquid is ejected by heating the liquid by an electrothermal converter. Among them, a recording head used in an ink jet recording method that ejects liquid by thermal energy has a high density of droplet ejection ports (orifices) for ejecting recording droplets to form flying droplets. Therefore, it is possible to record with high resolution.

Further, the recording head using the electrothermal converter as the energy generating means can be easily made compact as a recording head as a whole, and the recent technological progress in the semiconductor field and the remarkable improvement in reliability are ICs. Technology and micro processing technology can be fully utilized, and it is easy to make long and flat (two-dimensional). Therefore, multi-nozzle and high-density mounting are easy, and mass production is possible. Good nature,
It is possible to provide an inkjet recording head that is inexpensive to manufacture.

An ink jet recording head manufactured through a semiconductor manufacturing process using an electrothermal converter as the energy generating means is generally provided with a liquid passage corresponding to each ink ejection port, and each liquid passage is provided with a liquid passage. An electrothermal converter is provided as a means for applying thermal energy to the liquid filling the liquid passage to eject the liquid from the corresponding ink ejection port to form flying droplets. The liquid is supplied from a common liquid chamber that communicates with the passage.

FIG. 4 is a diagram showing a schematic structure of the above-mentioned ink jet recording head. In FIG. 4, a recording head 101 is a substrate 102 which is a first substrate after undergoing semiconductor manufacturing process steps such as etching vapor deposition and sputtering.
It has an electrothermal converter 103, an electrode 104, a cured active energy ray curable material layer 210 having a liquid path 110, and a top plate 106 which are formed on the above. However, in such a recording head unit 101, the recording liquid 112 is supplied from the liquid storage chamber (not shown) into the common liquid chamber 108 through the liquid supply pipe 107.

The liquid supply pipe 107 is connected to the inside of the common liquid chamber 108 via a liquid supply pipe connector 109. The recording liquid ink 112 supplied into the common liquid chamber 108 is supplied into the liquid passage 110 by a capillary phenomenon, and is stably held by forming a meniscus at the ink ejection port 111 at the tip of the liquid passage. Here, when the electrothermal converter 103 is energized, the liquid on the surface of the electrothermal converter is heated, a bubbling phenomenon occurs due to film boiling, and droplets are ejected from the ink ejection port 111 due to the growth of the bubbles. With the above-described configuration, it is possible to realize a multi-nozzle ink jet recording head with a high-density liquid passage piping having a discharge port density of 360 to 400 dots / inch.

The present invention is particularly effective in an ink jet recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording systems. With regard to its typical structure and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, the method is arranged on a sheet or liquid path holding a liquid (ink). By applying at least one drive signal to the electrothermal converter, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling, thermal energy is generated in the electrothermal converter, and the recording is performed. This is effective because film boiling is caused on the heat-acting surface of the head, and as a result, bubbles can be formed in the liquid (ink) that correspond one-to-one to this drive signal. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make this drive signal into a pulse shape because bubbles can be immediately and appropriately grown and contracted, so that liquid (ink) ejection with excellent responsiveness can be achieved.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed. As the configuration of the recording head, in addition to the combination configuration of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned nuclear specification, the heat acting portion is also provided. Alternatively, a configuration using US Pat. No. 4,558,333 and U.S. Pat. No. 4,459,600, which disclose a configuration in which is arranged in a bending region, may be used. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters.
Japanese Patent Laid-Open No. 59-138461, which discloses a structure in which an opening for absorbing a pressure wave of thermal energy is made to correspond to a discharge portion.
It can also be configured based on the publication.

In addition, the print head is replaceable with a print head of a replaceable chip type, which can be electrically connected to the main body of the apparatus or supplied with ink from the main body of the apparatus, or integrated with the print head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.
Further, it is preferable to add recovery means, preliminary auxiliary means, etc. to the recording head because the effects of the present invention can be further stabilized. Specific examples thereof include capping means, cleaning means, pressurizing or suctioning means for the recording head, preheating means using an electrothermal converter or another heating element or a combination thereof, and recording. It is also effective to perform a stable recording by performing a preliminary discharge mode in which another discharge is performed.

Further, the recording mode of the recording apparatus is not limited to the recording mode for only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. Alternatively, the device may be provided with at least one of full colors by color mixing. In the embodiment based on the present invention described above, the ink is described as a liquid, but an ink that solidifies at room temperature or below and softens at room temperature, or a liquid, etc. It is sufficient that the ink is in a liquid state when applied.

In addition, the temperature rise due to thermal energy is positively prevented by using it as energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in a standing state for the purpose of preventing evaporation of the ink. Whether or not ink is used, in any case, it is liquefied by applying thermal energy according to the recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches the recording medium. It should be noted that the use of an ink that has the property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-56.
No. 847 or Japanese Patent Application Laid-Open No. 60-71260, a mode in which it faces the electrothermal converter in the state of being held as a liquid or a solid in the recesses or through holes of the porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is
This is to execute the film boiling method described above.

<Detection of Ink Ejection Frequency> In the embodiment based on the present invention, the applied frequency of the pulse-shaped drive signal is set to be different for each of the plurality of ink ejection ports, so that the number of ejected drops can be corresponded one-on-one. The formation cycle of bubbles in the liquid (ink) is set to be the ink ejection frequency, which is different for each ejection port. Then, in order to prevent ejection abnormalities of the nozzles of the recording head, a microphone 14 is periodically disposed in the vicinity of a so-called blank ejection position, the ink ejection frequency is detected by the microphone 14, and bubbles are generated in the liquid (ink). Whether or not the ink has been formed is determined, and the presence / absence of ink in each ink ejection port or ejection abnormality is notified to the apparatus user based on the detected ink ejection frequency. In the facsimile apparatus of this embodiment, as shown in FIG. 5, on the front of the operation panel 40, a green tally lamp 41 for notifying the user of the telephone line that the telephone line is being used and a red tally lamp for notifying the abnormality of the apparatus are displayed. When the lamp 42 is provided and the absence of ink is detected by the microphone 14, the red tally lamp 42 is caused to blink and the LCD 43 provided on the upper surface of the operation panel 40 is caused to display “Cartridge Gamanari Nimashita”.

As described above, according to this embodiment, it is possible to detect the presence or absence of ink in the ink jet recording head having a plurality of ink ejection ports or the ejection abnormality for each ink ejection port and notify the user of the apparatus. effective.

[0043]

Other Embodiment 1 As another embodiment 1 of the above embodiment, during normal image recording, the ejection frequencies applied to a plurality of ink ejection ports are all set to the same ejection frequency to determine whether or not ink is ejected. The ejection frequency may be set to be different for each ink ejection port only when an abnormality is detected.

In this way, the recorded image is stable during normal image recording, and a good recorded image can be obtained.

[0045]

[Other Embodiment 2] As another embodiment 2 of the above embodiment, when detecting the presence or absence of ink ejection or ejection abnormality, pulse signals are applied to a plurality of ink ejection ports at different ejection frequencies, respectively. Simultaneous empty discharge from the discharge port,
The presence or absence of ejection of a plurality of inks or ejection abnormality may be detected by one microphone.

In this way, it is not necessary to discharge each ink ejection port one by one in order to detect the presence or absence of ink or ejection abnormality, and it is possible to detect the presence or absence of ink in all ink ejection ports in a short time. Alternatively, there is an effect that an abnormal discharge can be detected.

[0047]

[Third Embodiment] As a third embodiment of the above-described embodiment, the ink ejection frequencies applied to the respective ejection ports are set so as to have a "prime" relationship, and the ink of each ink ejection port is set. The presence or absence of ejection or abnormal ejection may be detected. This has the effect of making it easier to distinguish the ejection frequency of the ink ejection port of interest from the ejection frequency of the other ink ejection port in the detection waveform output from the microphone.

[0048]

[Other Embodiment 4] As another embodiment 4 of the above embodiment, as shown in FIG. 6, a plurality of ink tanks 1a and 1b are built in a cartridge type ink jet recording head, and each ink tank has a different type. It is also possible to store the above inks and give different ejection frequencies to the respective ink ejection ports.

By doing so, since different ink ejection ports correspond to each ink, there is an effect that it is possible to detect the presence or absence of ink or ejection abnormality for each ink.

[0050]

[Other Embodiment 5] As another embodiment 5 of the above embodiment, a plurality of ink tanks 1a, 1b (see FIG. 6).
The ink stored in the ink cartridge may be a single color ink having different densities, or a so-called color ink having different colors. In this way, when inks of the same color but different densities are stored, it is possible to obtain a recorded image with higher gradation than that expressed by one type of ink. Further, when four color inks of black, yellow, magenta and cyan are stored, a color image can be obtained.

By doing so, there is an effect that it is possible to detect the presence or absence of ink or the ejection abnormality for each ink. As a form of the recording apparatus according to the present invention, in addition to a facsimile apparatus having a transmitting / receiving function, a form provided integrally or separately as an image output terminal of an information processing device such as a computer, or a form of a copying apparatus combined with a reader or the like is used. It may be taken.

The present invention may be applied to a system composed of a plurality of devices such as a host computer, an interface and a printer, or to an apparatus composed of a single device such as a copying machine. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus. In this case, by reading the program from the recording medium that stores the program represented by the software for achieving the present invention into the system or apparatus, the system or apparatus can enjoy the effects of the present invention. Is possible.

[0053]

As described above, according to the first aspect of the present invention.
According to the invention described in (1), the frequency detection unit detects different ejection frequencies for each ejection port, and the state of the recording head is detected based on the detection signal from the frequency detection unit. The state of the recording head can be detected.

According to the second aspect of the invention, it is possible to detect the state of no ink in the ink tank of the recording head or the abnormal ink ejection state. Further, according to the third aspect of the invention, in the case of normal printing, all ejection ports are set to the same ejection frequency, and when detecting the state of the recording head, each ejection frequency is set to a different frequency. During normal image recording, it is possible to detect the presence or absence of ink in each ink ejection port or ejection abnormality so that a good recording image can be obtained.

Further, according to the invention described in claim 4, the ink is ejected from a plurality of ink ejection ports at the same time, and the frequency detecting means simultaneously ejects ink to the plurality of ejection ports from the ink tank or the ink ejection state is abnormal. Is detected, it is possible to detect the presence or absence of ink in all the ink ejection ports or the ejection abnormality in a short time. Further, according to the invention described in claim 5, since the respective ejection frequencies are set so as to satisfy the “prime” relation, the ejection abnormality of the ink ejection port of interest is regarded as the ejection abnormality of the other ink ejection port. The discharge abnormality can be detected without making a mistake.

According to the sixth aspect of the present invention, since the microphone is arranged in the vicinity of the ink ejection port as the frequency detecting means, the microphone has no ink based on the output of different ejection frequencies of each ejection port, or Discharge abnormality can be detected. According to the invention described in claim 7, a plurality of ink tanks are provided to store a plurality of inks,
Since a different ejection frequency is set for each ink ejection port corresponding to each ink, it is possible to detect the absence of ink or the ejection abnormality for each ink from the detected ejection frequency.

According to the eighth aspect of the present invention, the plurality of inks are single color inks having different densities or color inks having different colors, so that the ink having gradation from the detected ejection frequency is obtained. It is possible to detect the absence of ink or the discharge abnormality for each color of ink.

[Brief description of drawings]

FIG. 1 is a sectional view showing a facsimile apparatus applied as an embodiment of the present invention.

FIG. 2 is a diagram showing a detailed configuration of a recording unit of the present embodiment.

FIG. 3 is a block diagram showing a configuration of a control circuit of a recording unit in the facsimile apparatus of this embodiment.

FIG. 4 is a diagram showing a schematic configuration of an inkjet recording head of the present embodiment.

FIG. 5 is a perspective view showing the external appearance of the facsimile apparatus according to this embodiment.

FIG. 6 is a perspective view showing a configuration of an inkjet recording head provided with a plurality of ink tanks as another embodiment.

[Explanation of symbols]

 1 ... Recording head 1a ... Ink tank 1b ... Ink tank 2 ... Carriage 10 ... Carriage home sensor 12 ... Recording paper 13 ... Photo sensor 14 ... Microphone A ... Recording unit B ... Reading unit C ... Recording paper cassette and paper feeding unit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Noriyuki Aoki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Akio Okubo 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Incorporated (72) Inventor Atsushi Saito 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masakatsu Yamada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (8)

[Claims] 1. An ink jet recording apparatus equipped with a recording head having at least one ink tank and a plurality of ink ejection ports, and ejection control means for applying a recording signal at different ejection frequencies near the respective ink ejection ports. An inkjet recording apparatus comprising: a frequency detection unit that detects each ejection frequency; and a determination unit that determines a state of the recording head based on a detection signal from the frequency detection unit. 2. The state of the recording head is a state of no ink in the ink tank or a state of abnormal ink ejection,
2. The determination means notifies the state of no ink in the ink tank or abnormal ink ejection.
The inkjet recording device according to item 1. 3. In normal printing, all ejection ports are set to the same ejection frequency, and when detecting the state of the recording head, each ejection frequency is set to a different frequency. 1. The inkjet recording device according to 1. 4. The ink is ejected from the plurality of ink ejection ports at the same time, and the frequency detecting means simultaneously detects the absence of ink in the ink tank or the abnormal ejection state of the ink in the plurality of ejection ports. The inkjet recording device according to claim 2. 5. The ejection frequencies are set so as to satisfy a “prime” relationship, and the frequency detecting means simultaneously detects the absence of ink in the ink tank or the abnormal ink ejection state in a plurality of ejection ports. The inkjet recording apparatus according to claim 2, wherein the inkjet recording apparatus is an inkjet recording apparatus. 6. The ink jet recording apparatus according to claim 1, wherein the frequency detection unit is a microphone arranged near the ink ejection port. 7. A plurality of ink tanks for accommodating a plurality of inks are provided, and a different ejection frequency is set for each ink ejection port corresponding to each ink.
The inkjet recording device according to item 1. 8. The ink jet recording apparatus according to claim 7, wherein the plurality of inks are single color inks having different densities or color inks having different colors.