JP3178583B2 - Inkjet printer - 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 printer.

[0002]

2. Description of the Related Art Conventionally, various recording apparatuses for recording on recording media such as paper and OHP sheets have been proposed.
Among them, the ink jet recording apparatus ejects (discharges) ink directly from a recording head to recording paper, and has advantages such as low running cost and quiet recording operation. For this reason, for example, a printer for recording print data from a host computer, as well as a recording unit in a copying machine or a facsimile machine, has come to be used.

[0003] Incidentally, there is a method of detecting the remaining amount of ink in an ink jet recording apparatus by recording a mark for detecting the presence or absence of ink and determining whether the mark has been detected by the reflection type photosensor. There is also a method in which a light-emitting element and a light-receiving element of a photointerrupter provided with an ink discharge port interposed therebetween detect a change in light intensity due to the passage of ink therebetween, thereby detecting the presence or absence of ink.

[0004]

However, the former method of recording marks for detecting the presence or absence of ink among the above-mentioned conventional examples has a high detection accuracy, but on the other hand, records marks which are not originally necessary for detecting the presence or absence of ink. There is a problem that it has to be recorded on a medium.

In the latter method of detecting the presence or absence of ink based on a change in output when the ink crosses the optical axis of the photointerrupter, it is necessary to increase the light-shielding rate of the optical axis by ink in order to increase the detection accuracy. For this purpose, a slit is provided between the light-emitting and light-receiving elements. However, since the ink droplet flies over an extremely small range, the slit width of the light-receiving element must be narrow. For this reason, the alignment becomes very delicate, and normal detection cannot be performed due to a slight error of a component or a deviation in the ink droplet flying direction.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is possible to accurately detect the presence or absence of ink discharge without using a photosensor and a highly accurate positioning mechanism or control. It is an object of the present invention to provide an ink jet printer that can detect the ink jet printer.

In order to solve this problem, the ink jet printer of the present invention has the following configuration. That is, using an ink jet recording head having a nozzle row in which a plurality of nozzles are arranged along a predetermined direction,
Ink from multiple nozzles of the printhead
For inkjet printers that record on recording media
The inkjet recording head in the main scanning direction.
Scanning means for scanning relative to the recording medium along the
Scanning of the inkjet recording head by a scanning unit.
Provided at a predetermined position on the track, it has a sensor having for detecting ink ejected from the nozzles of the recording head, a light emitting element <br/> and a light receiving element, originating from the sensor
The optical element and the light receiving element are in a direction orthogonal to the main scanning direction.
Located outside the range of the nozzle row at
And the light emitting element and the light receiving element
The optical axis between them is at a predetermined angle with respect to the arrangement direction of the plurality of nozzles.
Are arranged so as to have a certain degree, and the nozzle row is
The optical axis can intersect with a predetermined width .

According to a preferred embodiment of the present invention,
Further, it is desirable to provide facsimile communication means and document image reading means.

Further, it is desirable to provide a notifying means for notifying externally when the ink discharge cannot be detected by the detecting means.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a side sectional view showing a configuration of a facsimile apparatus provided with a recording section for performing recording by a recording head according to an ink jet system, which is a typical embodiment of the present invention.

Referring to FIG. 1, a schematic configuration of the facsimile machine will be described. In FIG. 1, A is a reading unit that optically reads a document, B is a recording unit that performs recording in accordance with an ink jet system, and C is a recording unit that separates recording media such as recording paper P loaded in a paper feed cassette one by one. This is a paper feeding unit to be supplied to the unit B.

First, the flow of the recording paper P will be described.
The transport path of the recording paper P is as shown by the arrow G. That is,
The recording paper P stacked in the paper feeding cassette 1 of the paper feeding unit C is picked up by the paper feeding roller 2 and the retard roller 3 and sent to the recording unit B by the paper feeding roller 2.
The recording unit B conveys the recording paper P in accordance with the recording while performing recording by discharging ink onto the recording paper P by the recording head 5. When the recording is completed, the recording paper P is discharged and stacked on the discharge stacker 7 by the discharge roller 6.

Next, a specific configuration of the paper feeding section C will be described.

In FIG. 1, a sheet cassette 1 for stacking and storing a plurality of recording sheets P is provided with an intermediate plate 4 for stacking recording sheets P. The middle plate 4 is urged upward from the back surface by a middle plate spring 10 arranged to face the feed roller 2. Further, the intermediate plate 4 has a structure that can be easily replenished when the recording paper P decreases or runs out by being pressed downward by a cam or the like at the time of paper feed standby.

On the other hand, when the recording signal is detected and the paper feeding operation is started, the downward pressing of the middle plate 4 by the cam or the like is released.
The recording paper P is picked up by the paper feed roller 2.
The retard roller 3 is located at a position facing the paper feed roller 2 and changes the position of the recording paper P in conjunction with the middle plate 4. When the paper feeding operation is performed, the recording sheet P urged by the middle plate 4 and picked up by the paper feeding roller 2 is separated and fed only at the uppermost sheet by the cooperation of the paper feeding roller 2 in the J section. Send. The separated and fed recording paper P is conveyed to the recording unit B while being nipped so as to be sufficiently wound around the paper feed roller 2.

Further, a mechanism for discharging the recording paper P recorded by the recording section B will be described.

The recording paper P discharged by the discharge roller 6 is discharged and stacked on a discharge stacker 7. The discharge stacker 7 is provided with a discharge auxiliary tray 9 having a hinge K as a rotation center. When the recording paper P to be used is long, the discharge stacker 7 is rotated to move the discharge stacker in the recording paper discharge direction. Can be lengthened. Further, the paper discharge stacker 7 has a structure also serving as a cover of the paper feed cassette 1. The discharge stacker 7 and the discharge auxiliary tray 9 are provided with a plurality of ribs (not shown), and the recording paper P on which recording has been performed slides on the plurality of ribs and is sequentially stacked.

Next, the flow of the image document S will be described.

The document transport path is as shown by arrow F in FIG. In FIG. 1, an image original S is stacked on an original stacking tray 41 with its image surface facing down. Document loading tray 4
The image document S stacked on the sheet 1 is positioned by a slider 42 movable in the width direction. When the image document S is stacked on the document stacking tray 41, the document is pressed from above by a pre-conveyance spring 43 by a pre-conveyance pressing piece 43, and separated and preliminarily conveyed by cooperation with the separation roller 46.

Next, the preliminarily conveyed image original S is separated and conveyed one by one from below by the cooperation of the separation piece 45 and the separation roller 46 pressed by the ADF spring 47 from above. Further, the separation roller 46 also has a role of conveying the separated image document S to the reading position.
The image drawn on the image document S separated and conveyed to the reading position by the separation roller 46 in this manner is read by the photoelectric conversion sensor 48. The CS roller 49 is urged from above by the CS pressing spring 50 along the reading line of the photoelectric conversion sensor 48, and the separated and conveyed image document S is brought into close contact with the reading line. Further, the CS roller 49 determines the reading speed of the image document S in the sub-scanning direction (the direction in which the image document is transported), and also serves to discharge the image document S that has been read. Finally, the discharged image document S is placed on the document discharge tray 5.
1 is stacked. The document discharge tray 51 has a structure detachable from the apparatus main body.

FIG. 2 is a three-dimensional perspective view showing a detailed configuration of the recording section B. As shown in FIG. 2, the recording head 5 is a cartridge-type recording head that has an ink tank built-in and can be replaced with a new one when the ink runs out, and the ink ejection surface is directed downward. .

Here, the principle of ink ejection from the recording head will be described. The recording head section generally includes a fine liquid ejection port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and an energy for generating droplet forming energy to act on the liquid in the action section. And a generator.

As the energy generating portion, one using an electromechanical transducer such as a piezo element, irradiating an electromagnetic wave such as a laser, absorbing the liquid therein to generate heat, and generating a droplet by the action of the generated heat. There is a type that discharges and flies, and a type that discharges the liquid by heating the liquid with an electrothermal converter. Among them, a recording head using a method of discharging liquid by thermal energy can arrange liquid discharge ports (orifices) for discharging recording liquid droplets to form flying liquid droplets at high density. Therefore, recording can be performed at a high resolution.

Further, a recording head using an electrothermal transducer as an energy generating portion can be easily miniaturized as a whole, and has recently achieved remarkable advances in technology and reliability in the field of semiconductors, such as IC technology and microelectronics. The advantages of processing technology can be fully utilized, and it is easy to increase the length and form the surface (two-dimensional). In addition, the manufacturing cost can be reduced.

In general, a recording head manufactured through a semiconductor manufacturing process using an electrothermal converter for the energy generating section is provided with a liquid path corresponding to each ink discharge port, and a liquid path is provided for each liquid path. An electrothermal converter is provided as a means for applying thermal energy to the liquid satisfying the above, and discharging the liquid from the corresponding ink discharge port to form a flying liquid droplet. The structure is such that the liquid is supplied from the communicating common liquid chamber.

FIG. 3 shows a schematic configuration of the above-described ink jet recording head. The recording head unit 101 has undergone semiconductor manufacturing process steps such as etching deposition and sputtering, and has a cured active energy having an electrothermal transducer 103, an electrode 104, and a liquid path 110 formed on a substrate 102 as a first substrate. Line-curable material layer 210 and top plate 0
6. Thus, in such a recording head unit 101, the recording liquid 112 is supplied from a liquid storage chamber (not shown) through the liquid supply pipe 107 into the common liquid chamber 108.

Reference numeral 109 denotes a liquid supply pipe connector. The recording liquid 112 supplied into the common liquid chamber 108 is supplied into the liquid path 110 by capillary action, and is stably held by forming a meniscus at the ink discharge port 111 at the liquid path leading end. Then, when electricity is supplied to the electrothermal converter 103, the liquid on the electrothermal converter surface is overheated, 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, a multi-nozzle inkjet recording head can be formed with a high-density liquid passage pipe having a discharge port density of 360 to 400 dots / inch.

The present invention particularly provides an excellent effect in an ink jet recording apparatus which performs recording by forming flying droplets by utilizing thermal energy among ink jet recording systems.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 796. This method can be applied to both the so-called on-demand type and continuous type. In particular, in the case of the on-demand type, liquid (ink)
By applying at least one drive signal that gives a rapid temperature rise exceeding the nucleate boiling corresponding to the recorded information to the electrothermal transducer arranged corresponding to the sheet or liquid path in which This is effective because heat energy is generated in the electrothermal transducer, causing film boiling on the heat-acting surface of the recording head, and as a result, air bubbles in the liquid (ink) corresponding one-to-one to this drive signal can be formed. It is. By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed. When the drive signal is formed into a pulse shape, the growth and shrinkage of the bubble are performed immediately and appropriately, so that the ejection of a liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

As the configuration of the recording head, in addition to the combination of the discharge port, the liquid path, and the electrothermal converter (linear liquid flow path or right-angled liquid flow imaginary) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333 and U.S. Pat. No. 4,558,333 which disclose a configuration in which a heat acting portion is arranged in a bending region.
No. 4,591,600 may be used. In addition, Japanese Patent Application Laid-Open No. Sho 5 discloses a configuration in which a common slit is used as a discharge port of an electrothermal converter for a plurality of electrothermal converters.
Japanese Patent Application Laid-Open No. 9-123670 discloses a structure in which an opening for absorbing a pressure wave of thermal energy is made to correspond to a discharge portion.
A configuration based on JP-A-9-138461 can also be adopted.

In addition, the print head is exchangeable with a print head of the chip type, which is electrically connected to the main body of the apparatus and can supply ink from the main body of the apparatus, or is integrated with the print head itself. Alternatively, a cartridge type recording head provided with an ink tank may be used.

It is preferable to add recovery means for the recording head, preliminary auxiliary means, and the like, since the effects of the present invention can be further stabilized. Specific examples include capping means for the recording head, cleaning means, pressurizing or sucking means, pre-heating means using an electric converter or another heating element or a combination thereof, and separate from recording. It is also effective to perform the preliminary ejection mode for performing the ejection in order to perform stable printing.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be a single recording head or a combination of plural recording heads. Alternatively, the apparatus may be provided with at least one of full colors by color mixture.

In the above-described embodiment, the ink is described as a liquid. However, an ink which solidifies at room temperature or lower and which is softened at room temperature or a liquid is used. What is necessary is for the ink to be in a liquid state at the time of application.

In addition, the temperature rise due to heat 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 to prevent evaporation of the ink. Either ink may be used, or in any case, the ink may be liquefied by application of heat energy according to the recording signal and ejected as a liquid ink, or may already start to solidify when reaching the recording medium. The use of an ink having a property of being liquefied for the first time by thermal energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or Japanese Patent Application Laid-Open No. 60-71260, in which the porous sheet is held as a liquid or solid substance in the recesses or through holes of the porous sheet and opposes the electrothermal converter. It may be. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

Returning to FIG. 2, the configuration of the recording section B will be described.

In FIG. 2, while the carriage 15 holds the recording head 5 with high accuracy, the carriage 15 moves in a direction (main scanning direction, arrow H direction) perpendicular to the recording paper P transport direction (sub-scanning direction, arrow G direction). Move back and forth. The carriage 15 is slidably held by a guide rod 16 and an abutting portion 15a. The reciprocating movement of the carriage 15 is performed by a pulley 17 and a timing belt 18 driven by a carriage motor 30 (not shown). At this time, a recording signal and electric power given to the recording head 5 are transmitted to a main body of the apparatus by a flexible cable 19. Supplied from the circuit. The recording head 5 and the flexible cable 19 are connected by press-contacting their respective contacts. Also,
A cap 20 is provided at a home position of the carriage 15 of the recording unit B, and functions as an ink receiving unit. The cap 20 is moved up and down as needed, and when it rises, it is in close contact with the recording head 5 and covers its nozzle to prevent evaporation of ink and adhesion of dust.

In this apparatus, in order to position the recording head 5 and the cap 20 so as to be relatively opposed to each other, a carriage home sensor 21 provided on the apparatus main body and a light shielding provided on the carriage 15 are provided. Board 15b
Is used. As the carriage home sensor 21, a transmission type photo interrupter is used. When the carriage 15 moves to the standby position, light emitted from a part of the carriage home sensor 21 is blocked by the light shielding plate 15b. Using the recording head 5
And that the cap 20 is at a relatively opposed position.

The recording paper P is fed upward from the lower side in FIG.
The paper is bent in the horizontal direction by the paper feed roller 2 and the paper guide 22 and transported in the direction of arrow G (sub-scanning direction). The paper feed roller 2 and the paper discharge roller 6 are each driven by a recording motor (not shown), and a carriage 15
The recording paper P is conveyed in the sub-scanning direction with high precision in conjunction with the reciprocating movement of the recording paper P. Further, a spur 23 which is made of a material having high water repellency in the sub-scanning direction and comes into contact with the recording paper P only at its blade-shaped circumferential portion is provided. The spurs 23 are arranged at a plurality of locations facing the paper discharge roller 6 at predetermined intervals in the main scanning direction by a bearing member 23a. The recording paper P is guided and conveyed without affecting the recording paper P.

The photo sensor 8 is a transmission type photo interrupter, and is provided on a track on which the carriage 15 performs a scanning movement as shown in the figure. Then, as shown in FIG. 4, after the recording head 5 is moved to the position of the photosensor 8, the change in the received light intensity due to the flight of the ink droplet ejected from the nozzle of the recording head 5 causes the recording head 5 to be in the ink-out state. It is determined whether or not. The photo sensor 8 used here uses an infrared LED as a light emitting element, a lens is integrally formed on the LED light emitting surface, and light can be projected substantially parallel to the light receiving element. A phototransistor is used for the light receiving element, and a 0.7 mm × 0.7 mm hole (slit 45) is formed on the light receiving surface of the light receiving element by a mold member.
Are formed on the optical axis.

In order to move the recording head 5 to a position where the photo sensor 8 is located, for example, the home position (H
The distance (L) from the position of the recording head 5 in P) to the photosensor 8 is converted into the number of driving steps of a motor for driving the carriage 15 and is set as a constant in a control program for executing the recording operation in advance. I have. Thus, the recording head 5 can be positioned at the position of the photo sensor 8.

The problem here is that the slit provided in the light receiving element is very small. That is, it is necessary that the light emitting element and the light receiving element are located on a straight line in which the ink ejection ports of the recording head 5 are arranged. However, in order to accurately position the recording head in such a state, the recording head 5
In addition to moving the (carriage 15) with high accuracy, the photo sensor 8 must also be held with high positional accuracy.

Therefore, in the present embodiment, as shown in FIG. 5, the detection optical axis between the light emitting element and the light receiving element of the photo sensor 8 has an angle θ relative to the arrangement direction of the ink ejection ports of the recording head 5. Was held. By taking such a structure,
An allowable range given by the illustrated width W occurs, and the problem of accuracy is solved.

In other words, conventionally, there was only one row, but by adopting the structure of this embodiment, an allowable range up to the range indicated by the width W can be obtained. However, if the angle θ is increased, the peak value, which is the output signal of the photosensor, decreases, so that the angle θ cannot be increased. This angle depends on the accuracy of the photosensor 8 and also depends on the number of nozzles of the recording head, the distance between the nozzles, the diameter of the nozzles, and the like.

FIG. 6 is a block diagram showing a control unit of the facsimile apparatus shown in FIG.

In FIG. 6, reference numeral 24 denotes a control unit for controlling the entire apparatus. The control unit 24 includes a CPU 25 and a CP.
It has a ROM 26 storing a control program and various data executed by the U 25, a RAM 27 used as a work area when the CPU 25 executes various processes, and a RAM 27 for temporarily storing various data. .

As shown in FIG. 6, the recording head 5 is connected to the control unit 24 via a flexible cable 19, and the flexible cable 19 is connected to the recording unit 5 by the control unit 24.
, A control signal line and an image signal line. The output of the photosensor 8 is converted into a numerical value by an A / D conversion circuit 28 and can be analyzed by the CPU 25.

The carriage motor 30 is a motor drive circuit 3
The motor is rotatable by the number of pulse steps according to 2. Further, the control unit 24 controls the carriage motor 30 via the motor drive circuit 33, the transport motor 31 via the motor drive circuit 32, the read motor 52 via the motor drive circuit 53, and outputs the output from the carriage home sensor 21. You are typing.

Further, the control unit 24 controls the reading sensor 4
8. Image data input devices such as a printer interface 54 for receiving recording commands and recording data from an external computer 56 and a line control circuit 55 for receiving data received from a public telephone line 57 are connected to perform facsimile transmission / reception and copying. It can operate as a printer of an external computer. Further, the control unit 24 is provided with an operation panel 58 on which the device user performs various operations and instructions.
Are connected. The operation panel 58 is provided with an LCD 59 for displaying a message.

The process for detecting the remaining amount of ink of the embodiment having the above configuration will be described with reference to the flowchart of FIG. still,
The program according to the flowchart is stored in the ROM 26, and is called and executed when a predetermined amount of printing is completed (in the above embodiment, when recording of one page is completed). Further, since the image recording processing procedure itself is not directly related to the present invention, the description thereof is omitted.

When recording for one page is completed, the CPU
When the H.224 calls this processing, first, the carriage 15
Is moved to the position of the photosensor 8 (step S
1). Next, ink is ejected (all ink ejection ports are driven) (step S2), and it is determined whether or not ink is ejected based on the signal level from the photo sensor 8 (step S3).

If there is no change in the signal from the photo sensor 8, it is determined that ink is not ejected, that is, it is determined that there is no ink, and the LCD 59 provided on the operation panel 58 prompts the user to exchange the reason and the recording head 5. A message is displayed (step S4).

Thereafter, the process proceeds to step S5, in which the carriage 15 is moved to the home position to prepare for the next recording.

In this way, every time printing of one page is completed, the operation of detecting the remaining amount of ink is performed.

As described above, according to the present embodiment, it is possible to reliably detect the presence or absence of ink during a normal printing operation without controlling the positioning of the printing head (carriage) with high accuracy. Become.

A type in which the ink ejection ports provided in the recording head are set obliquely or the recording head itself is set obliquely on the carriage, and the ink ejection ports are not driven all at once but are driven sequentially (power supply source) In the case of the apparatus described above, when the arrangement direction of the ink ejection ports substantially coincides with the above angle with respect to the sub-scanning direction, the detection light of the photo sensor 8 as shown in FIG. The axis may be the same as the sub-scanning direction.

In the above-described embodiment, the present invention is applied to the facsimile machine, and the ink remaining amount detecting operation is performed each time one page is printed (received image or copied by an instruction from an operation panel (not shown)). When recording received images,
Negotiation of the completion of reception in page units may be used as a trigger, and for copying, detection between documents may be used as a trigger. Further, the above processing may be performed based on the number of reciprocations of the carriage based on the size of the recording paper.

For example, the present invention may be applied to a single printer connected to a computer. That is, during printing from the host computer, the above processing is performed each time recording of one page is completed. In some cases, the above processing may be performed when a predetermined command is received from the host computer. Further, when connected to the host computer via the phase communication interface, the result of detecting the remaining amount of ink may be returned to the host computer. By doing so, the operator of the host computer can detect the remaining amount of ink in the connected printer while staying at home and know the timing of replacing the recording head. In particular, when a printer is connected to a network or the like, even a remote printer can know the presence or absence of ink, which is very convenient.

Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), a single device (for example, a copying machine, a facsimile, etc.) May be applied.

[0061]

As described above, according to the present invention, the presence / absence of ink ejection can be detected with high accuracy without using a high-precision positioning mechanism or control using a photosensor.

[0062]

[Brief description of the drawings]

FIG. 1 is a sectional view of a facsimile apparatus according to an embodiment.

FIG. 2 is a perspective view illustrating a configuration of an inkjet recording unit according to the embodiment.

FIG. 3 is a perspective view illustrating a configuration of a recording head according to the embodiment.

FIG. 4 is a diagram illustrating an operation of detecting the presence or absence of the remaining amount of ink in the embodiment.

FIG. 5 is a diagram illustrating a positional relationship between a photo sensor and a recording head for detecting the remaining amount of ink in the embodiment.

FIG. 6 is a block diagram of a control unit according to the embodiment.

FIG. 7 is a flowchart illustrating a processing procedure for detecting the remaining amount of ink in the embodiment.

FIG. 8 is a diagram illustrating a positional relationship between a photosensor and a recording head for detecting the remaining amount of ink in another embodiment.

[Explanation of symbols]

 5 Recording Head 8 Photo Sensor 20 Cap 21 Home Position Sensor

Continued on the front page. (72) Inventor Yukio Nobata 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Takashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takeshi Kenno 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-4-7159 (JP, A) JP-A-4-269549 (JP, A JP-A-4-65250 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41J 2/175

Claims (5)

(57) [Claims] A plurality of nozzles are arranged along a predetermined direction.
Using an ink jet recording head with a nozzle row
Ink from multiple nozzles of the inkjet recording head
Inkjet that ejects ink and performs recording on the recording medium
In the printer, the inkjet recording head is moved forward along the main scanning direction.
Scanning means for scanning the recording medium, and movement of the inkjet recording head by the scanning means.
Provided at a predetermined position on the orbit of査, for detecting ink ejected from the nozzles of the recording head, has a sensor having a light emitting element and a light receiving element, the light-emitting element of the sensor and The light receiving element is in the main scanning direction.
Outside the range of the nozzle row in a direction orthogonal to
And the light emitting element and the front.
The optical axis between the light receiving element and the array direction of the plurality of nozzles
Are arranged so as to have a predetermined angle with respect to
The nozzle row intersects the optical axis with a predetermined width
An inkjet printer characterized by being made possible. 2. The method according to claim 1, wherein the sensor receives light by the light receiving element.
It outputs a signal corresponding to the change in the amount, In the optical axis formed between the light emitting element and the light receiving element
Ejection of ink from the ink jet recording head
And, based on the signal output by the sensor,
Whether the ink jet recording head discharges ink
2. The ink according to claim 1, wherein the absence is determined.
Jet printer. 3. The method according to claim 2, wherein the predetermined angle is 3 degrees.
The ink-jet pudding according to claim 1 or 2, wherein
Ta. 4. Furthermore, to claim 1, characterized in that it comprises a facsimile communication unit and the document image reading means
3. The inkjet printer according to any one of 3 . 5. Further, when the ink discharge can not be detected by the sensor, the inkjet printer according to any one of claims 1 to 4, characterized in that it comprises a notifying means for externally notifying.