JPH06238906A - Ink-jet recording device - Google Patents

Abstract

PURPOSE:To provide an ink-jet recording device which can maintain a function of an optical sensor detecting a width of recording paper and perform accurate and appropriate recording. CONSTITUTION:The ink-jet recording device performs recording by discharging ink to a recorded medium from recording heads 9A-9D, which is provided with a wiping mechanism 30 wiping nozzle surfaces of the recording heads 9A-9D and a paper width detecting sensor which is arranged on a carriage 6 moving the recording heads 9A-9D and detects optically a width of the recorded medium, a quantity of discharging ink is stored accumulatively in a data memory 23, when the quantity of the discharging ink stored accumulatively becomes at least a prescribed quantity, the carriage 6 and wiping mechanism 30 are controlled by a CPU 21, the surface of the paper width detecting sensor is wiped by the wiping mechanism 36 and dirt is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording ink on a recording medium by ejecting ink from a recording head which scans the recording medium.

[0002]

2. Description of the Related Art FIG. 2 is a perspective view showing an outline of the construction of a conventional ink jet recording apparatus for performing color recording.

In FIG. 2, a recording medium 1 such as a paper or a plastic sheet is supported by a pair of conveying rollers 2 and 3 arranged above and below a recording area, and an arrow is formed by a conveying roller 3 driven by a sheet feeding motor 4. It is conveyed in the A direction. A guide shaft 5 is provided in front of the transport rollers 2 and 3 in parallel therewith. The carriage 6 is reciprocated along the guide shaft 5 in the direction of arrow B via the wire 8 by the output of the carriage motor 7.

A recording head 9 which is an ink jet head is mounted on a carriage 6 as a head moving means. This recording head 9 is for a color image,
Four recording heads 9, that is, black heads 9A, which are arranged in the scanning direction of the carriage and are provided corresponding to inks of cyan (C), magenta (M), yellow (Y), and black (Bk), respectively. , Cyan head 9B,
It is composed of a magenta head 9C and a yellow head 9D. The recording heads are arranged with a certain interval (for example, 12 mm). Further, optical means 201 such as an infrared reflection type sensor for detecting the paper width which is the scanning direction to the recording medium is arranged on the carriage. On the front surface of each recording head 9, that is, on the surface facing the recording surface of the recording medium 1 at a predetermined interval (for example, 0.8 mm), a plurality of (for example, 48 or 64) ink ejection ports are arranged in the scanning direction of the carriage. Ink ejection portions are arranged in a line in the vertical direction in the intersecting direction.

On the operation panel 160 attached to the outer case (not shown) of the recording apparatus, in addition to key setting portions such as an online / offline switching key 60A, a line feed key 60B, a form feed key 60C, and a recording mode switching key 60D. A display unit 65 including warning LEDs such as a plurality of alarm LEDs 61A and power LED 61B is provided.

When performing a printing operation, the CPU and its peripheral circuits provided in the control unit (not shown) first use the sheet feeding motor 4 for transportation based on the printing data sent from the host device 100. The recording medium 1 is moved to a predetermined position. Next, while the carriage 6 is being moved, the width (paper width) of the recording medium in the scanning direction is detected by using an optical means 201 such as an infrared reflection type sensor. Based on this paper width, the print data sent from the host device 100 is processed, the print head 9 is controlled, and appropriate printing is performed on the print medium 1.

An ink jet recording head (hereinafter referred to as a recording head) 9 of an ink jet recording apparatus for recording by an ink jet method comprises an ink tank and a nozzle portion for ejecting ink droplets.
The basic operation of such a recording head will be described with reference to FIG.

FIG. 3 is a block diagram schematically showing a cross section of the recording head 9 (the same applies to any of the recording heads 9A to 9D) shown in FIG.

In FIG. 3, a plurality of ink ejection openings for ejecting ink are provided at predetermined intervals in the direction orthogonal to the scanning direction on the recording head surface facing the recording medium 1 such as recording paper. The ink ejection nozzle 10 is formed. Each ink ejection nozzle 10 is filled with ink 13. Each ink ejection nozzle 10 is provided with an electrothermal converter 11, and a heat driver 14 for turning on / off the power supply to the electrothermal converter 11 is provided.

A control circuit 2 for performing the above energization control
A circuit board with 9 is arranged on the carriage 6 (FIG. 2). A print data signal and a heat signal are output from the control circuit 29, and are input to the print data serial / parallel conversion circuit 16 and the heat signal generation circuit 17 on the print head 9, respectively. The heat driver 14 to be energized is selected by the signals output from both circuits.

When the heat driver 14 is selected and the power is turned on, the electrothermal converters (heating resistors, etc.) 11 provided for the respective ink ejection nozzles 10 are electrically heated to form a film on the ink in the ink ejection nozzles 10. A bubble (bubble) 12 is generated by causing a boiling phenomenon. Ink is ejected from the ink ejection nozzle 10 by the pressure increase due to the bubble 12 to form a flying ink droplet 13A. By making the ink droplets 13A adhere to the recording medium 1, recording is performed by a dot pattern.

After that, when the heating resistor 11 is de-energized, the ink discharge nozzle 10 is cooled and the bubble 12 disappears. Then, the ink 13 is newly supplied from the ink liquid passage 10A, and the ink ejection nozzle 10 is again supplied with the ink 13
Filled with.

[0013]

A paper width detecting means using a conventional optical means will be described with reference to FIG.

In FIG. 4, reference numeral 1 is a recording medium such as paper, and 202 is a platen. A carriage 6 has Y, M, C, and Bk recording heads and a paper width detection sensor 201.

The internal structure of a general optical reflection type sensor 201 comprises a photodiode 201a and a phototransistor 201b as shown in FIG. Light such as infrared rays emitted from the photodiode 201a is reflected on the platen 202 or the recording medium 1 and enters the light receiving portion of the phototransistor 201b. The collector portion of the phototransistor 201b is previously connected to a power source (5V in the illustrated example) via a resistor, and the potential of this collector portion fluctuates depending on the incident light as shown in FIG.

The paper width detecting means using the conventional optical means recognizes by detecting the level difference of the reflected light amount when the recording medium is present and when it is not. That is, the output is compared with a certain judgment level, and if it is larger than that, it is judged as the platen, and if it is smaller, it is judged as the recording medium.

In an ink jet recording apparatus, ink is ejected from a recording head nozzle to perform recording. Therefore, when recording is performed for a long time, mist-like ink (hereinafter referred to as mist) splashed from a recording medium is used as the reflection type sensor. May adhere to 201. When the sensor 201 gets dirty with this mist,
The detected level fluctuates. In the above example, since the amount of incident light is small, the level during scanning of the recording medium rises and the paper width cannot be detected correctly.

Further, since the above-mentioned abnormal situation is the same when the photodiode 201a of the sensor is destroyed for some reason, the apparatus having such control is erroneously determined to be the sensor failure and recorded. May not be possible.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and maintains the function of an optical sensor for detecting the width (paper width) of the recording medium in the scanning direction, which is accurate and appropriate. It is an object of the present invention to provide an inkjet recording device capable of various recording.

[0020]

Therefore, an ink jet recording apparatus according to the present invention is an ink jet recording apparatus for recording by ejecting ink from a recording head onto a recording medium, and a nozzle surface of the recording head is wiped. Nozzle cleaning means, paper width detection means disposed on the carriage for moving the recording head to optically detect the width of the recording medium, dirt determination means for determining dirt of the paper width detection means, and determination of dirt determination means The above-mentioned object is achieved by a control means for controlling the nozzle cleaning means based on the above and performing a dirt removing operation for the paper width detecting means.

[0021]

With the above construction, the width of the recording medium is detected by the paper width detecting means arranged on the carriage, and the recording head is moved by the carriage to eject ink onto the recording medium to perform recording. Moreover, the nozzle surface of the recording head is wiped by the nozzle cleaning means.

Then, the control means controls the nozzle cleaning means based on the judgment of the dirt judging means for judging the dirt of the paper width detecting means to perform the dirt removing operation for the paper width detecting means,
The function of the paper width detecting means is maintained normally.

[0023]

1 is a block diagram showing the configuration of an embodiment of the present invention. The same or corresponding parts as those of the conventional device are designated by the same reference numerals, and a duplicate description will be omitted.

In FIG. 1, a CPU 21, which is a microprocessor, is connected to a host device 100 through an interface 22, and stores programs and recording commands stored in a ROM-type program memory 24, an EEPROM-type data memory 23, and the like. The recording operation is controlled on the basis of the data and the command signal and the recording information signal read from the host device 100 into the working memory 25.

In the portion hidden by the carriage 6 shown in FIG. 2, a capping mechanism for protecting the recording head when recording is not performed, an absorber for wiping the nozzle surface of the recording head, and an indicating member therefor. The wiping mechanism 30 (FIG. 1) and the recovery motor 71 (FIG. 1) for operating these are provided.

When performing a recording operation, a control board (not shown)
The upper CPU 21 and its peripheral circuits first move the recording medium 1 to a predetermined position by using the sheet feeding motor 4 for conveyance based on the recording data sent from the host device 100. Next, while scanning the carriage 6, the width (paper width) of the recording medium in the scanning direction is detected by using an optical means 201 such as an infrared reflection type sensor. Based on this paper width, the print data sent from the host device 100 is processed, the print head 9 is controlled, and appropriate printing is performed on the print medium 1.

Then, the CPU 21 controls the data memory 23.
The amount of ink to be ejected is calculated on the basis of the recording information stored in, and this is cumulatively stored in the data memory 23. The CPU 21 controls the carriage 6 and the wiping mechanism 30 to wipe the surface of the sensor 201 by the wiping mechanism 30 when the accumulated ink amount becomes a certain value or more.

With the above structure, color recording is performed by ejecting ink from the plurality of recording heads 9A to 9D having different ink colors. Then, the wiping mechanism 30 wipes the nozzle surface of the recording head. When a predetermined amount of ink is ejected,
The optical mechanism 20 which is a paper width sensor by the wiping mechanism 30.
By wiping the surface of No. 1, the paper width can always be detected correctly and appropriate color inkjet recording can be carried out.

(Other Embodiments) In the above embodiment, the amount of ink to be ejected is stored, and the paper width sensor 201 is wiped by the wiping mechanism 30 when a certain amount is exceeded. For example, when detecting the paper width, the level at the time of scanning the recording medium is compared with a certain value smaller than the determination level shown in FIG. 6, and the wiping control is performed when the level becomes higher than this. It can also be configured to perform.

Further, in this case, the level of the recording medium before the wiping control is stored in the working memory 25, the wiping control of the paper width sensor 201 is performed, and the level of the recording medium is measured again. If there is no change in the sheet width, it is possible to determine that the paper width sensor 201 itself is out of order and to notify the outside by a warning light of the operation panel 160, a display plate, a buzzer, or the like.

With the above structure, the same effect as that of the above embodiment can be exhibited.

The present invention is particularly effective in an ink jet recording head and a recording apparatus for recording by forming flying droplets by utilizing thermal energy among the ink jet recording methods.

Regarding the typical structure and principle thereof, see, for example, US Pat. Nos. 4,723,129 and 4740.
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 to the electrothermal converter arranged corresponding to the sheet or the flow path in which the is held, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. , 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 the bubble growth and contraction are immediately and appropriately performed, so that the ejection of the liquid (ink) 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. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,244 of the invention relating to the rate of temperature rise of the heat acting surface.

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 passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. A configuration using US Pat. No. 4,558,333 or US Pat. No. 4,459,600, which discloses a configuration in which the heat acting portion is arranged in the bending region, may be used.

In addition, JP-A-59-123670 discloses a structure in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and a pressure wave of thermal energy is absorbed. It is also possible to adopt a configuration based on Japanese Patent Application Laid-Open No. 59-138431, which discloses a configuration in which the opening corresponds to the ejection portion.

Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium which can be recorded by the recording apparatus, a combination of a plurality of recording heads as disclosed in the above-mentioned specification provides the length. Either of the structure satisfying the requirement or the structure as one recording head integrally formed may be used.

In addition, by being mounted on 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, pressurizing or suctioning means for the recording head, preheating means by an electrothermal converter or a heating element other than this, or a combination thereof, and an ejection different from recording. It is effective to perform the preliminary ejection mode for performing stable recording.

Further, the recording mode of the recording apparatus is not limited to the recording mode only for 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 embodiments of the present invention described above, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and softens at room temperature, or is a liquid, or the above-mentioned. In the inkjet method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form.

In addition, the temperature rise due to 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, such as ink that is liquefied by applying heat energy according to a recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches a 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 JP-A-60-71260, a mode in which the porous sheet is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recess or through hole 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.

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

[0044]

As described above, according to the present invention, the width of the recording medium is detected by the paper width detecting means arranged on the carriage, and the recording head is moved by the carriage to eject ink onto the recording medium. To record. Moreover, the nozzle surface of the recording head is wiped by the nozzle cleaning means.

Then, the dirt removal operation for the paper width detection means is performed by the nozzle cleaning means based on the judgment of the dirt judgment means for judging the dirt of the paper width detection means, and the function of the paper width detection means is maintained normally, so that the recording is performed. Accurate and appropriate recording is possible without erroneously recognizing the width of the medium. Since the nozzle cleaning means provided in the recording apparatus also removes dirt on the paper width detecting means, it is not necessary to provide a new mechanism, and the present invention can be carried out while suppressing the cost increase.

Further, when the dirt removing operation is performed on the paper width detecting means by the nozzle cleaning means, and when the dirt on the paper width detecting means is not removed, the display means indicates that the paper width detecting means is out of order. The above effect can be made more reliable.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment.

FIG. 2 is a perspective view of a conventional inkjet recording device.

FIG. 3 is a block diagram of a recording head.

FIG. 4 is an explanatory diagram of paper width detection.

FIG. 5 is a block diagram of a paper width detection sensor.

FIG. 6 is an output explanatory diagram of a paper width detection sensor.

[Explanation of symbols]

 1 Recording Medium 6 Carriage 9 Recording Head 9A Black Recording Head 9B Cyan Recording Head 9C Magenta Recording Head 9D Yellow Recording Head 10 Ink Ejection Nozzle 11 Electrothermal Converter 12 Bubble (Bubble) 13 Ink 13A Flying Ink Drop 14 Heat driver 17 Heat signal generation circuit 21 CPU 23 Data memory 24 Program memory 25 Working memory 27 Carriage motor control circuit 29 Recording head control circuit 30 Sweeping mechanism 60A-60D Operation keys 61A, 61B Alarm LED 65 Display unit 100 Host device 160 Operation panel 201 Paper width detection sensor 202 Platen

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical display location B41J 29/42 A 9113-2C E 9113-2C 9113-2C B41J 29/00 J (72) Inventor Takayuki Murata 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (3)

[Claims] 1. An ink jet recording apparatus for performing recording by ejecting ink from a recording head onto a recording medium, comprising nozzle cleaning means for wiping a nozzle surface of the recording head and a carriage for moving the recording head. The paper width detecting means for optically detecting the width of the recording medium, the dirt judging means for judging the dirt of the paper width detecting means, and the nozzle cleaning means based on the judgment of the dirt judging means for controlling the dirt on the paper width detecting means. An inkjet recording apparatus, comprising: a control unit that performs a removing operation. 2. In addition to the structure according to claim 1, a display means for notifying the state of the ink jet recording apparatus to the outside is provided,
When the dirt removal operation is performed on the paper width detection means by the nozzle cleaning means, it is determined whether or not the dirt on the paper width detection means has been removed, and when it is determined that the dirt has not been removed,
An ink jet recording apparatus characterized by displaying on a display means that the paper width detection means is out of order. 3. The recording head is a recording head that ejects ink by utilizing thermal energy, and is an inkjet recording head that includes a thermal energy converter for generating thermal energy to be applied to the ink. Item 1
Alternatively, the inkjet recording device according to the item 2.