JPH0994947A - Ink jet printer and control thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect the presence of ink without receiving the effect of ink mist. SOLUTION: A shutter member 81 is downwardly moved for the first time when a carriage is moved to a photosensor 8 in order to detect the presence of ink to expose the light emitting element and photodetector of the photosensor and ink is emitted to detect whether ink remains. When this detection operation is completed, the shutter member 81 is again raised to protect the photosensor 8 and a slit 80 from ink.

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 and its control method.

[0002]

2. Description of the Related Art Conventionally, various recording apparatuses have been proposed for recording on a recording medium such as paper or OHP sheet.
Among them, the ink jet recording apparatus ejects (discharges) ink directly from the recording head onto the recording paper, and has advantages such as low running cost and quiet recording operation. For this reason, for example, it has come to be used not only as a printer that records print data from a host computer but also as a recording unit in a copying machine or a facsimile machine.

In order to detect the remaining amount of ink in an ink jet recording apparatus, there is a method in which a mark for detecting the presence or absence of ink is recorded and it is judged whether or not the mark can be detected by the reflection type photo sensor. There is also a method of detecting the presence or absence of ink by detecting a change in light intensity due to the passage of ink between the light emitting element and the light receiving element of the photo interrupter provided with the ink ejection port sandwiched therebetween.

[0004]

However, although the detection accuracy is high when the former mark for detecting the presence or absence of ink is recorded, the mark is purposely recorded on the recording medium in order to detect the presence or absence of ink. This is a waste of the recording medium, and it is not user-friendly.

In the latter method of detecting the presence or absence of ink by the change in output when the ink crosses the optical axis of the photo interrupter, it is necessary to increase the light blocking rate of the optical axis by the ink in order to improve the detection accuracy. Therefore, the width of the slit provided between the light emitting element and the light receiving element needs to be narrow because the flying droplets are extremely small. However, if the slit width is narrow, the slit may be filled up due to a mistaken ejection of an ink droplet or the like, and it may not function at all.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an ink jet printer and a control method therefor capable of accurately detecting the presence or absence of ink without being affected by the mist of ink. Is to provide.

In order to solve this problem, for example, the ink jet printer of the present invention has the following configuration. That is, an inkjet printer that forms an image by ejecting ink onto a recording medium from at least one ink ejection port, and includes a photo sensor including a light emitting element and a light receiving element, and a photo sensor between the light emitting element and the light receiving element of the photo sensor. At this point, the detection means for causing the recording head to eject ink and detecting the presence or absence of ink by the change in the output from the photosensor, and the light emitting surface and the light receiving surface of the photosensor except for the detection operation timing of the detection means. And a protection means for protection.

According to a preferred embodiment of the present invention,
The protection unit controls the drive unit when a shutter member that blocks the light emitting surface and the light receiving surface of the photo sensor, a drive unit that moves the shutter member, and a predetermined amount of printing are completed, and the shutter member. And a control means for urging the detection means by moving the light emitting surface and the light receiving surface to a position where they are opened.

Further, by providing the facsimile communication means and the document image reading means, it is possible to adapt to a facsimile machine.

Further, it may be provided with an informing means for informing externally when the ink ejection cannot be detected by the detecting means.

[0011]

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

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

With reference to FIG. 1, a schematic structure of the facsimile apparatus will be described. In FIG. 1, A is a reading unit that optically reads a document, B is a recording unit that performs recording according to an inkjet method, and C is a recording medium such as recording paper P stacked in a paper feed cassette, which is separated and recorded one by one. This is a paper feeding unit that supplies the paper to the unit B.

First, the flow of the recording paper P will be described.
The conveyance path of the recording paper P is as shown by an arrow G. That is,
The recording paper P stacked in the paper feed cassette 1 of the paper feed unit C is picked up by the paper feed roller 2 and the retard roller 3 and sent to the recording unit B by the paper feed roller 2.
In the recording unit B, the recording head 5 ejects ink onto the recording paper P to perform recording, and the recording paper P is conveyed in accordance with the recording. 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 structure of the paper feeding section C will be described.

In FIG. 1, a paper feed cassette 1 for stacking and storing a plurality of recording papers P is provided with an intermediate plate 4 for stacking the recording papers P. The middle plate 4 is urged upward from the back surface by a middle plate spring 10 arranged to face the feeding roller 2. Further, the middle plate 4 is structured so that it can be easily replenished when the recording paper P is reduced or lost due to being pressed downward by a cam or the like during the 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 intermediate 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 at a position facing the paper feed roller 2 and changes the position of the recording paper P in conjunction with the intermediate plate 4. When the paper feeding operation is performed, the recording sheet P, which is urged by the middle plate 4 and picked up by the paper feeding roller 2, is separated and fed by the J section in cooperation with the paper feeding roller 2. To send. The recording paper P that has been separated and fed is conveyed to the recording unit B while being sandwiched so as to be sufficiently wrapped around the paper feed roller 2.

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

The recording paper P ejected by the paper ejection roller 6 is ejected and stacked on the paper ejection stacker 7. The paper ejection stacker 7 is provided with a paper ejection auxiliary tray 9 having a hinge K as a center of rotation, and is rotated when the recording paper P to be used is long so that the paper ejection stacker is ejected in the recording paper ejection direction. It can be made longer. Further, the paper discharge stacker 7 has a structure that also serves as a cover of the paper feed cassette 1. A plurality of ribs (not shown) are provided on the paper discharge stacker 7 and the paper discharge auxiliary tray 9, and the recording paper P on which recording is performed slides on the plurality of ribs and is sequentially stacked.

Further, the flow of the image original S will be described.

The document transport path is as shown by arrow F in FIG. In FIG. 1, the image document S is stacked on the document stacking tray 41 with its image side facing down. Document stacking tray 4
The image document S stacked on the sheet 1 is positioned by the slider 42 movable in the width direction. When the image original S is stacked on the original stacking tray 41, the original is pressed by the preliminary conveying pressing piece 43 from above by the preliminary conveying spring 44, and is separated and preliminarily conveyed in cooperation with the separation roller 46.

Next, the pre-conveyed image originals S are separated and conveyed one by one from the lower side by the cooperative action of the separating piece 45 and the separating roller 46 pressed by the ADF spring 47 from above. Further, the separation roller 46 also serves to convey the separated image original S to the reading position.
The image drawn on the image original 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 original S is brought into close contact with the reading line. Further, the CS roller 49 not only determines the reading speed of the image original S in the sub-scanning direction (conveyance direction of the image original) but also serves to discharge the image original S that has been read. Finally, the discharged image original S is stored in the original discharge tray 5
1 is discharged and stacked. The document discharge tray 51 has a structure that can be attached to and detached from the apparatus main body.

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

Here, the principle of ink ejection from the recording head will be described. The recording head portion generally has a fine liquid discharge port (orifice), a liquid passage and an energy acting portion provided in a part of this liquid passage, and energy for generating droplet forming energy for acting on the liquid in the acting portion. And a generator.

The energy generating section uses an electromechanical transducer such as a piezo element, irradiates electromagnetic waves such as a laser, causes the liquid in the area to absorb the heat, and generates heat, and the generated heat causes the droplets to drop. There are those that are made to eject and fly, or those that are made to heat the liquid by an electrothermal converter and eject the liquid. Among them, in a recording head using a method of ejecting a liquid by thermal energy, liquid ejection ports (orifices) for ejecting recording liquid droplets to form flying liquid droplets can be arranged at high density. Therefore, it is possible to record at high resolution.

Further, the recording head using the electrothermal converter as the energy generating portion can be easily miniaturized as a whole, and the IC technology and the micro technology which have been remarkably improved in the technological progress and reliability in the recent semiconductor field. Since the advantages of processing technology can be fully utilized and it is easy to make it long and flat (two-dimensional), it is easy to make multiple nozzles and high-density mounting, and mass production is possible. It is also possible to reduce the manufacturing cost.

A recording head manufactured through a semiconductor manufacturing process using an electrothermal converter in the energy generating section as described above generally has a liquid passage corresponding to each ink ejection port, and the liquid passage is provided for each liquid passage. An electrothermal converter is provided as a means for applying thermal energy to the liquid that fills the liquid and ejecting the liquid from the corresponding ink ejection port to form droplets for flight. The liquid is supplied from a common liquid chamber that is in communication with each other.

FIG. 3 shows a schematic structure of the above-mentioned ink jet recording head section. The recording head unit 101 is subjected to semiconductor manufacturing process steps such as etching vapor deposition and sputtering, and the electrothermal converter 103, the electrode 104, and the cured active energy having the liquid passage 110 formed on the substrate 102 which is the first substrate. Wire curable material layer 210 and top plate 0
It is composed of 6. 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.

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 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. Then, when the electrothermal converter 103 is energized, the liquid on the surface of the electrothermal converter is overheated and 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 form a multi-nozzle ink jet recording head portion 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 memory systems.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 4,740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal that gives a rapid temperature rise over the nucleate boiling corresponding to the recorded information to the electrothermal converter arranged corresponding to the sheet or liquid path holding the , It is effective because it generates heat energy in the electrothermal converter and causes film boiling on the heat-acting surface of the recording head, resulting in the formation of bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis. Is. 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 constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid flow passage or the right-angled liquid flow imaginary) as disclosed in the above-mentioned respective specifications. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of No. 459600 may be used. In addition, Japanese Unexamined Patent Application Publication No. Sho 5-5 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 Application Laid-Open No. 9-123670 and Japanese Patent Application Laid-Open No. Sho 5 (1993) -58
A configuration based on JP-A-9-138461 can also be adopted.

In addition, by being attached to the apparatus main body, it can be electrically connected to the apparatus main body and can be supplied with ink from the apparatus main body by a replaceable chip type recording head or the recording 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 electric converter or a heating element other than this, or a combination thereof, and recording other than recording. It is also effective to perform the stable recording by performing the preliminary discharge mode for discharging.

Further, the recording mode of the recording apparatus is not limited to the recording mode of 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 present embodiment 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 the thermal energy is positively prevented by using it as the 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. In some cases, whether ink is used, the ink is liquefied by applying thermal energy according to the recording signal and ejected as a liquid ink, or the one that already begins to solidify when it reaches the recording medium. The use of an ink having a 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-54-5684.
No. 7 or Japanese Patent Laid-Open No. 60-71260, such a form as to be opposed to an electrothermal converter in a 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 to execute the above-mentioned film boiling method.

Next, the structure of the recording section B will be described with reference to FIG.

In FIG. 2, while the carriage 15 holds the recording head 5 with high precision, the carriage 15 is in a direction (main scanning direction, arrow H direction) orthogonal to the conveyance direction of the recording paper P (sub scanning direction, arrow G direction). Move back and forth. The carriage 15 is slidably held by the guide rod 16 and the abutting portion 15a. The reciprocating movement of the carriage 15 is carried out 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 supplied to the recording head 5 are supplied to the 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 each other. Also,
A cap 20 is provided at the home position of the carriage 15 of the recording unit B and functions as an ink receiving unit. The cap 20 moves up and down as needed, and when it rises, it comes into close contact with the recording head 5 to cover its nozzle portion and prevent evaporation of ink and adhesion of dust.

Now, 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 in the apparatus main body and a light shielding provided in the carriage 15 are provided. Board 15b
Is used. A transmission type photo interrupter is used for the carriage home sensor 21, and when the carriage 15 moves to the standby position, the 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 the cap 20 are relatively opposed to each other.

The recording paper P is fed upward from the lower side in the drawing,
The paper is bent in the horizontal direction by the paper feed roller 2 and the paper guide 22, and is conveyed 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 if necessary, the carriage 15
The recording paper P is conveyed in the sub-scanning direction with high accuracy in conjunction with the reciprocating movement of the recording paper P. Further, in the sub-scanning direction, there is provided a spur 23 which is made of a material having high water repellency and which comes into contact with the recording paper P only at its blade-shaped circumferential portion. The spurs 23 are arranged at a plurality of positions facing the paper discharge roller 6 and are separated by a predetermined length in the main scanning direction by the bearing member 23a. The recording paper P is guided and conveyed without affecting the above.

As shown in FIG. 4, the photosensor 8 is arranged between the cap 20 and the edge of the recording paper P so as to face the nozzle row 5c of the recording head 5, and is ejected from the nozzles of the recording head 5. It is a transmissive photo interrupter that directly optically detects the formed ink drop, and by ejecting ink at this position, the ink-free state of the recording head 5 can be determined from the output result. The photo sensor 8 used here uses an infrared LED as a light emitting element, and a lens is integrally formed on the LED light emitting surface so that light can be projected substantially parallel to the light receiving element. A phototransistor is used for the light receiving element, and a hole of 2 mm × 0.5 mm is formed on the light receiving surface of the light receiving element by a molding member on the optical axis, and the detection range is high in the entire area between the light receiving element and the light emitting element. The width is narrowed to 2 mm and the width is narrowed to 0.5 mm. Further, the optical axis connecting the light emitting element and the light receiving element is arranged substantially parallel to the nozzle row 5c of the recording head 5, the distance between the light emitting element and the light receiving element is wider than that of the nozzle row 5c of the recording head 5, and the recording is performed with the optical axis. When the positions of the nozzle rows 5c of the head 5 are substantially the same,
All ink droplets ejected from each nozzle of the recording head 5 are configured to be able to pass through the detection range between the light emitting element and the light receiving element. When the ink droplet passes through the detection range, the ink droplet blocks light from the light emitting side, reduces the amount of light to the light receiving side, and changes in the output of the phototransistor, which is a light receiving element, can be obtained.

The nozzle array of the recording head 5 and the photo sensor 8
Similarly to the positioning with the cap 20, the carriage home sensor 21 provided in the main body of the apparatus is used to position the and so as to be relatively opposed to each other.

In this embodiment, as shown in FIG. 4, the nozzle row 5 of the recording head 5 at the home position (HP) is located.
The distance (L) moving from the position c to the optical axis of the photosensor 8 is converted into the number of steps of the motor that drives the carriage 15, and is set as a constant in the control program that executes the recording operation in advance. In this way, by moving the carriage by a fixed amount after detecting the home position, it is possible to accurately position the ink column of the recording head 5 and the optical axis of the photo sensor 8 relatively opposite to each other.

FIG. 5 shows details around the photosensor 8 in the embodiment.

As described above, in the present embodiment, the photosensor 8 is provided to discriminate the presence or absence of ink when the ejected ink crosses the optical axes of the light emitting element and the light receiving element of the transmissive photo interrupter type sensor. . Then, as shown in the drawing, the slits 8 of each of the light emitting side element and the light receiving side element
0 is provided with a shutter member 81. The shutter member 81 is in a position to cover the slit 80 during normal printing and recording. The recording head 5 moves to the position of the photo sensor 8 by performing the operation described above after the printing and recording of one recording sheet is completed. After that, a predetermined amount of ink is ejected from the recording head 5 in accordance with a command from the control unit described later.
The shutter member 81 is moved down to the position where both the light emitting side element and the light receiving side element release the slits, or before moving to the position. After that, an ink ejection operation is performed to detect the presence or absence of ink. After the ejection of ink is completed, the recording head 5 returns to the home position where the cap 20 of the ink receiving means is located, and waits for a command for the next recording. Further, the shutter member 46 returns to the position where it covers the normal slit 80.

In the embodiment, the vertical movement of the shutter member 81 is made by the solenoid. That is, since the drive source for driving the carriage for moving the recording head and the drive source for moving the shutter member 81 are different from each other, the recording head and the shutter member 81 are simultaneously moved to improve the recording throughput. ing.

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

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

As shown in FIG. 6, the recording head 5 is connected to the control section 24 via a flexible cable 19, and the flexible cable 19 is connected from the control section 24 to the recording head 5.
The control signal line and the image signal line are included. Further, the output of the photo sensor 8 is digitized by the A / D conversion circuit 28 and can be analyzed by the CPU 25. Further, the control unit 24, at the timing described above,
The solenoid drive circuit 83 is controlled so that the shutter member 81 provided near the photo sensor 8 is moved up and down.

The carriage motor 30 is a motor drive circuit 3
It is a motor that can rotate depending on the number of pulse steps by 3. 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, and the reading motor 52 via the motor drive circuit 53, and outputs from the carriage home sensor 21. You are typing.

Furthermore, the control unit 24 controls the reading sensor 4
8. A printer interface 54 for receiving recording commands and recording data from an external computer 56, an image data input device such as a line control circuit 55 for receiving received data from a public telephone line 57 are connected, and facsimile transmission / reception and copying are performed. , Can be operated as a printer of an external computer. Furthermore, the control unit 24 includes an operation panel 58 for the device user to perform various operations and instructions.
Are connected. The operation panel 58 is provided with an LCD 59 for displaying a message.

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

First, when the recording of one sheet of recording paper is completed, the carriage 15 is moved to the position of the photo sensor 8, and the solenoid driving circuit 83 is energized to move the shutter member 81 downward to move the photo sensor 8. Open (step S1). Next, when the movement of the carriage 15 is completed, ink is ejected so as to cross the optical axis of the photo sensor 8 (step S2).

Then, it is determined whether or not the signal from the photo sensor 8 has changed (step S3).

If there is no change in the signal from the photo sensor 8, it is judged that ink is not ejected, that is, there is no ink, and the reason for this and the recording head 5 are displayed on the display section provided on the operation panel (not shown). A message prompting exchange is displayed (step S4).

Thereafter, the process proceeds to step S5, the carriage 15 is moved to the home position, and the solenoid drive circuit 8 is controlled to control the shutter member 81.
Is returned to the original position, that is, the position protected by the photosensor 8 (step S45), and this processing is ended.

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

As described above, according to the present embodiment, there is an effect that it is possible to reliably detect the presence or absence of ink without the detection failure due to the contamination of the light emitting / light receiving element due to the mist of the ink during the normal recording operation and the filling of the slit. is there.

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

Further, in the above embodiment, the shutter member 81
The photo sensor 8 was made to function and was protected by moving up and down by a solenoid. However, it is sufficient that the function and protection of the photosensor can be achieved, and thus the present invention is not limited to the above-described embodiment.

Further, for example, the present invention may be applied to a single printer connected to a computer. That is, the above process is performed every time printing of one page is completed during printing from the host computer. In some cases, the above process may be performed when a predetermined command is received from the host computer. Furthermore, when the host computer is connected to the host computer via the phase direction communication interface, the ink remaining amount detection result may be returned to the host computer. By doing so, the operator of the host computer can detect the ink remaining amount of the printer connected to the host computer and know the replacement time of the recording head. In particular, when a printer is connected to a network, it is very convenient because even a remote printer can know the presence or absence of ink.

Even when the present invention is applied to a system composed of a plurality of devices (eg, host computer, interface device, reader, printer, etc.), a device composed of one device (eg, copying machine, facsimile, etc.) May be applied to.

As described above, according to the embodiment of the present invention, since the ink presence sensor can always obtain a stable output in the photo interrupter system, the user can be surely informed that the ink has been completely consumed. Will be able to.

In the photo interrupter system, since the ink presence / absence sensor can always obtain a stable output, the user can be surely notified that the ink has been completely consumed.

[0067]

As described above, according to the present invention, the presence or absence of ink can be accurately detected without being affected by the mist of ink.

[0068]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a facsimile device according to an embodiment.

FIG. 2 is a perspective view showing a configuration of an inkjet recording unit in the embodiment.

FIG. 3 is a perspective view showing a configuration of a recording head in the embodiment.

FIG. 4 is a diagram for explaining an operation of detecting the presence / absence of an ink remaining amount in the embodiment.

FIG. 5 is a perspective view of a photo sensor unit for detecting the remaining amount of ink in the embodiment.

FIG. 6 is a block configuration diagram of a control unit in the embodiment.

FIG. 7 is a flowchart showing a processing procedure of remaining ink amount detection in the embodiment.

[Explanation of symbols]

 5 recording head 8 photo sensor 20 cap 21 home position sensor 80 slit 81 shutter member 82 solenoid drive circuit

Front page continued (72) Inventor Shinichiro Gun 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Takashi Ono 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Nobuo Nohata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (6)

[Claims] 1. An ink jet printer for forming an image by ejecting ink from at least one ink ejection port onto a recording medium, comprising: a photo sensor comprising a light emitting element and a light receiving element; and a light emitting element and a light receiving element of the photo sensor. Between the elements, ink is ejected by a recording head, and a detection unit that detects the presence or absence of ink by a change in the output from the photo sensor; and a light emitting surface of the photo sensor other than the detection operation timing of the detection unit. An inkjet printer, comprising: a protection unit that protects a light-receiving surface. 2. The protection means controls the drive unit when a shutter member that blocks the light emitting surface and the light receiving surface of the photosensor, a drive unit that moves the shutter member, and a predetermined amount of printing is completed. The inkjet printer according to claim 1, further comprising: a control unit that moves the shutter member to a position where the shutter member is opened from the light emitting surface and the light receiving surface, and urges the detection unit. 3. The inkjet printer according to claim 1, further comprising a facsimile communication unit and a document image reading unit. 4. The ink jet printer according to claim 1, further comprising an informing unit for informing the outside when ink ejection cannot be detected by the detecting unit. 5. A recording head having at least one ink ejection port, and a photosensor provided at a predetermined position within a scannable range of the recording head and optically detecting ink ejection from the recording head. A method of controlling an inkjet printer, comprising: a photosensor protection unit that transitions the photosensor to either a protected or non-protected state from the outside under predetermined control, when a predetermined timing is reached, A first control step of moving the recording head to the photo sensor position and controlling the photo sensor protection means to shift the photo sensor to a non-protected state; and setting the photo sensor to the non-protected state and thereafter. After that, the recording head is energized to eject ink, and the presence or absence of ink ejection is determined based on the signal from the photo sensor. And a third control step for controlling the photosensor protection means to shift the photosensor to a protection state after the control by the second control step. Inkjet printer control method. 6. The method of controlling an ink jet printer according to claim 5, further comprising a notification step of making an external notification when ink ejection cannot be detected by the second control means. .