JPH0596835A - Image recording device - Google Patents

Abstract

PURPOSE:To prevent an offset of a recording medium, which is generated when an ink is discharged to an area in which the recording medium does not exist in such a case that the recording medium is carried while being tilted, and the ink is hit into a carrying means, from happening for an image recording device which performs recording by discharging an ink from the ink jet recording head. CONSTITUTION:A long sides sensor 4, which extends in parallel with the recording direction of a recording head, is arranged on the upstream side in the carrying direction of the recording position by the recording head, and the width of a recording paper P in that direction is continuously detected to regulate the operation of the recording head in such a manner that recording would be performed within the width. By doing this, the hitting in of an ink does not take place at areas which are out of the recording paper P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording apparatus having functions such as a facsimile, a copying machine, a printer and the like, and an image recording apparatus used as an output device such as a multifunction peripheral or a workstation having those functions.

[0002]

2. Description of the Related Art The non-impact recording method has recently attracted interest in that noise generation during recording is negligibly small. Among them, the inkjet recording method, which is capable of high-speed recording and can perform recording on so-called plain paper without requiring a special fixing process, is an extremely powerful recording method.

A recording head applied to an ink jet recording apparatus generally applies a fine liquid discharge port (orifice), a liquid passage, an energy acting portion provided in a part of this liquid passage, and a liquid in the acting portion. An energy generating means for generating a droplet forming energy is provided.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element, or an electromagnetic wave such as a laser is radiated so that the liquid in the liquid absorbs the heat to generate heat. Recording method using an energy generating means for ejecting and flying droplets by the action of, or recording using an energy generating means for heating a liquid by an electrothermal converter such as a heating element having a heating resistor to eject the liquid. There are ways. Among them, a recording head used in an inkjet recording method for ejecting a liquid by thermal energy has a high density of liquid ejection ports (orifices) for ejecting recording liquid droplets to form flying liquid droplets. Since it is possible to record, it is possible to record with high resolution. Among them, the recording head using the electrothermal converter as the heat energy generating means is easy to be made compact as a recording head 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 multi-nozzles and high-density mounting. It is possible to provide an inkjet recording head which is inexpensive in manufacturing cost and an apparatus including the head.

An ink jet recording head manufactured through a semiconductor manufacturing process using an electrothermal converter as an energy generating means is generally provided with a liquid passage corresponding to each orifice, 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 passage to eject the liquid from the corresponding orifice to form flying droplets. The liquid is supplied to each of these liquid passages from a common liquid chamber that communicates with each liquid passage.

FIG. 5 shows an example of the above-mentioned ink jet type image recording apparatus. In the figure, reference numeral 301 denotes a scanner unit for reading a document and converting it into an electric signal, and the converted electric signal is given to a recording head unit 305 of a printer unit 302 as a drive signal. Paper feed unit 303
A recording medium such as a recording paper and an OHP film (hereinafter also referred to as a recording paper) is accommodated in the paper, and the paper is separated one by one as needed and is fed toward the belt conveying unit 304. When the recording paper is conveyed on the belt conveying unit 304,
An image is recorded by the recording head unit 305, and is sent out to the tray 308 via the fixing paper discharge unit 307. 30
Reference numeral 6 is a recovery system unit, which has a function of maintaining the recording head unit 305 in a state in which recording is always possible.

[0007]

In such an image recording apparatus, when an image is recorded by ejecting ink from the recording head onto the conveyed recording paper, the recording paper on the conveyor belt should be in an appropriate position. It is important to take. For example, when the recording paper is significantly skewed or when the conveyance timing is shifted, when ink is ejected from the recording head according to a signal sent from the scanner unit, the ink is ejected directly toward the conveyor belt. It will be.

Generally, the conveyor belt is provided with a belt cleaner, but this belt cleaner does not operate during normal recording, and its cleaning member (for example, a blade) does not contact the conveyor belt. This is to keep the torque applied to the conveyor belt during recording to a minimum because the driving of the conveyor belt requires high accuracy. Therefore,
For example, if the ink is ejected to the conveyor belt as described above on a large-sized recording paper of A3 size or the like, the portion of the conveyor belt where the ink is ejected wraps around to the downstream side of the belt cleaner. Therefore, in order to clean the conveyor belt, the belt has to be rotated about once, and it takes time to return to the recording operation. Also, if the recording paper is ejected as it is even if the ink is ejected to the belt, it cannot be detected that the ink has been ejected to the conveyor belt, and the recording on the succeeding recording paper is not possible. Therefore, there is also a problem that the back surface of the recording paper is smeared.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve such a problem. Therefore, the present invention provides a recording head section for recording an image on a recording medium,
Conveying means for conveying the recording medium to the recording position by the recording head, and detection means arranged in front of the recording position for continuously detecting the width of the recording medium in the recording direction by the recording head. And means for controlling the recording operation of the recording head in accordance with the detected width.

[0010]

According to the present invention, for example, in an image recording apparatus for recording by ejecting ink from the recording head, by providing a means for continuously detecting the width of the recording medium before the recording position by the recording head. Since the position of the recording medium can be accurately grasped and the ink can be prevented from being ejected to the conveying means or the like, the recording can be performed without causing the back stain of the recording medium.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic sectional view showing a main part of an image recording apparatus according to an embodiment of the present invention, which is applicable to the structure shown in FIG.

The illustrated image recording apparatus is an ink jet printer, and recording heads 1C, 1M, 1Y and 1Bk are provided facing the conveyor belt 2 provided on the conveyor belt. The recording sheet fed by a sheet feeding device (not shown) arranged further upstream (right side in the drawing) of the conveying system is sent to the side of the conveying belt 2 by the registration rollers 5 and 6 at a predetermined timing. The image is recorded by the ejection ports provided on the bottom surface of the recording heads 1C, 1M, 1Y, 1Bk during the process of being conveyed by.

The conveyor belt 2 is an endless belt, is laid between two rollers 7 and 8, and is rotated in the direction of the arrow in the figure by the roller 7 engaged with a drive mechanism (not shown), and its upper surface is conveyed. It becomes a face.

On the other hand, an adsorbing charger 9 is arranged near the conveyor belt 2 so as to charge the surface of the conveyor belt 2. The conveyor belt is made of a resin material such as polyurethane or rubber, and can electrostatically attract the recording paper by charging the surface.

The recording paper electrostatically adsorbed on the conveyor belt is
After an image is recorded by the recording heads 1C, 1M, 1Y, and 1Bk, it is peeled from the surface of the conveyor belt due to the rigidity of the recording paper, and is discharged to the left in FIG.

Here, the recording heads 1C, 1M, 1Y, 1B
Reference numeral k denotes an ink jet recording head to which inks of cyan, magenta, yellow and black are supplied. Each recording head is accurately fixed to the head block 3, and the parallelism of each head, the distance between the heads, etc. are guaranteed within a desired accuracy.

A sensor 4 is arranged in the head block 3 upstream of the head 1 (on the right side in the drawing). The sensor 4 is longer than the maximum recording paper width by about 5 to 10 mm and is arranged parallel to the recording head. The sensor is a reflection type optical sensor such as CCD, which emits light from the light emitting portion toward the object to be measured,
The reflected light is detected by the light receiving section. The sensor 4 detects the position of the recording paper on the conveyor belt.

FIG. 2 shows a schematic configuration example of a control system when the main part shown in FIG. 1 is applied to the device shown in FIG.

Reference numeral 100 denotes a controller which constitutes a main control unit of the apparatus, and includes a CPU 101 for executing processing means described later with reference to FIG. 3, a ROM 103 for storing a program corresponding to the processing procedure and other fixed data,
It has a RAM 105 used for storing print data, data relating to the width of the print medium, and the like, and controls each part.

The scanner unit 301 includes the controller 100.
Under the control of 1, the original is read and the read data is sent to the controller 100. A switch group 110 is composed of various switches such as a copy switch for instructing reading of a document and image recording. A sensor group 112 is arranged in each part of the apparatus including the recording medium sensor 4. Reference numeral 114 is a display unit for displaying a device state such as a setting mode and an error.

Reference numeral 116 denotes a capping mechanism which relatively moves a head unit 305 having the recording heads 1Y, 1M, 1C, 1Bk and a recovery system unit 306 including a cap corresponding to each head so as to perform the capping position and recording. Set both at the hour position. Reference numeral 118 denotes a feeding / conveying mechanism, which includes a feeding unit for feeding the recording medium from the paper feeding unit 303, a registration roller 5, a conveyance belt driving roller 7, and the like, and a motor for driving each unit related to feeding / conveying the recording medium. ..

FIG. 3 shows an example of a recording control procedure according to this example.

When a recording start command is given by operating the copy switch or the like, this procedure is started, and step S1
The feeding / transporting of the recording medium is started at. In step S3, it is determined whether or not the sensor 4 has detected the recording medium, that is, in this case, the front end of the recording medium. If not detected, the process proceeds to step S5. For example, if the registration rollers 5 and 6 are not detected within a predetermined time after starting to rotate, an error message such as a paper jam is displayed in step S7, and the process ends. ..

On the other hand, when the recording medium is detected, the process proceeds to step S9, the width (paper width) of the recording medium at the sensor portion passing position is recognized, and the position on the recording medium is detected based on this in step S11. Determine the recording range of. In step S13, the leading edge of the recording medium is at the recording position (recording head 1C
(A position facing the ejection port of No. 2), and if negative, the process returns to step S9 to continue the paper width recognition and the determination of the recording range. This is in consideration of a certain distance as the arrangement position of the sensor 4 and the arrangement position of the recording head 1C. A memory can be used to store the determined recording range. In that case, the capacity of the memory may be the number of lines commensurate with the distance. Also,
If the memory of the FIFO is used and the output information indicates the width of the portion of the recording medium just at the recording position, the management based on the storage address is not required. Then, the recording range determination information can deactivate the drive signal for the element group of the recording head. Further, if the memory area storing the image information to be recorded is appropriately operated using the determined range information, the memory for storing the range information becomes unnecessary.

After the recording medium reaches the recording position, the recording operation is performed based on the range determined in step S15. Then, in step S17, it is determined whether or not the detection of the recording medium by the sensor 4 has disappeared, that is, in this case, the rear end of the recording medium has been detected. If a negative determination is made here, the procedure from step S9 is repeated, and if the trailing edge is detected, a recording operation of a predetermined amount corresponding to the above distance (step S19) is executed, and then the recording medium is ejected (step S21). ) To end this procedure.

In the above process, a proper amount of margin may be provided at the front end and the rear end of the recording medium. In addition, it goes without saying that the drive timings of the recording heads 1M, 1Y, 1C, and 1Bk are delayed corresponding to the head arrangement intervals.

As described above, in this example, the recording paper passing directly under the sensor is detected, and the ejection of ink from the recording head is regulated so that the recording is performed only on the portion where the recording paper is detected.

FIG. 4A shows a view from above of the relationship between the sensor and the recording paper when the recording paper is conveyed in a normal state. For example, when the recording paper P is obliquely inclined with respect to the conveyor belt and is adsorbed and conveyed, the position of the recording paper P under the recording head changes from moment to moment (FIG. 4B). Immediately before that, since the recording paper P is detected by the sensor, ink will not be ejected onto the conveyor belt without the recording paper P. That is, FIG. 4 (a)
The ink is ejected only to the shaded portion on the recording paper regardless of the normal transport state as shown in FIG. 4 or the skewed state as shown in FIG.

The surface of the conveyor belt 2 is of a color having a light reflectance different from that of a generally used recording medium, and is between the light quantity difference between the light reflected by the recording medium and the light reflected by the surface of the conveyor belt. What is necessary is just to generate a light amount difference that can be detected by the sensor.

Further, in this embodiment, one long sensor 4 is used.
Although the system for detecting the presence / absence of the recording paper has been described by using, the same effect can be obtained even if the sensor 4 is divided into a plurality in the width direction of the recording paper.

(Others) Although the present invention can be applied to recording apparatuses of various recording systems, particularly when it is adopted in the inkjet recording system, the energy used for ejecting ink among them is used. As a result, an excellent effect can be obtained in a recording head and a recording apparatus of a system that includes a means for generating heat energy (for example, an electrothermal converter or a laser beam) and causes a change in the state of ink by the heat energy. This is because such a system can achieve high density recording and high definition recording.

Regarding the typical structure and principle thereof, see, for example, US Pat. No. 4,723,129 and No. 4740.
What is done using the basic principles disclosed in 796 is preferred. This method is a so-called on-demand type,
It can be applied to any of the continuous type, but especially in the case of the on-demand type, it can be applied to the sheet holding the liquid (ink) or the electrothermal converter arranged corresponding to the liquid path. By applying at least one drive signal corresponding to the recorded information and giving a rapid temperature rise exceeding nucleate boiling, heat energy is generated in the electrothermal converter, and film boiling is caused on the heat acting surface of the recording head. Liquid (ink) corresponding to this drive signal as a result
This is effective because bubbles can be formed inside. Due to the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection openings 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. 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 discharge port, the liquid passage, and the electrothermal converter (the straight liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. U.S. Pat. No. 4,558,333, U.S. Pat. No. 44, which discloses a configuration in which a heat acting portion is arranged in a bending region.
The configuration using the specification of No. 59600 is also included in the present invention. In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy is provided. The effect of the present invention is effective even if the configuration corresponding to the ejection portion is disclosed in Japanese Patent Laid-Open No. 59-138461. That is, according to the present invention, recording can be surely and efficiently performed regardless of the form of the recording head.

Furthermore, the present invention can be effectively applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium that can be recorded by the recording apparatus. Such a recording head may have a configuration that satisfies the length by a combination of a plurality of recording heads or a configuration as one recording head integrally formed.

In addition, even in the case of the serial type as in the above example, the recording head fixed to the main body of the apparatus or the ink jet from the main body of the apparatus is electrically connected to the main body of the apparatus by being attached to the main body. The present invention is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, as the constitution of the recording apparatus of the present invention, it is preferable to add an ejection recovery means of the recording head, a preliminary auxiliary means and the like because the effects of the present invention can be further stabilized. Specifically, heating is performed by using a capping means, a cleaning means, a pressure or suction means for the recording head, an electrothermal converter or a heating element other than this, or a combination thereof. Examples thereof include a preliminary heating unit for performing the discharge and a preliminary discharge unit for performing discharge different from the recording.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of inks having different recording colors and densities are supported. A plurality of pieces may be provided. That is, for example, 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 either integrally formed of the recording heads or a combination of a plurality of them. The present invention is also very effective for an apparatus provided with at least one of full-color recording modes by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature may be used. Or, in the inkjet method, it is common to adjust the temperature of the ink itself within the range of 30 ° C. or higher and 70 ° C. or lower to control the temperature so that the viscosity of the ink is within the stable ejection range. At times, a liquid ink may be used. 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 in order to prevent the evaporation of the ink, it is solidified and heated in a standing state. You may use the ink liquefied by. In any case, by applying heat energy such as ink that is liquefied by applying heat energy according to the recording signal and liquid ink is ejected, or that begins to solidify when it reaches the recording medium. The present invention can be applied to the case where an ink having a property of being liquefied for the first time is used. In this case, the ink is
JP 54-56847 A or JP 60-7.
As described in Japanese Patent No. 1260, it may be configured to face the electrothermal converter in a state of being held as a liquid or a solid in the concave portion or the through hole of the porous sheet. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus of the present invention, other than the one used as an image output terminal of information processing equipment such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmission / reception function can be used. It may be in a form or the like.

[0041]

As described above, according to the image recording apparatus of the present invention, the width of the document is continuously detected before recording by the recording head, and the recording operation is performed according to the detected width. By doing so, even when the recording paper is skewed, it is possible to prevent the ink from being directly ejected onto the conveyor belt in the inkjet recording system, and it is possible to eliminate the back stain on the recording paper.

Further, since the shape and position of the recording paper can be accurately grasped by the sensor, there is also an effect that the margin portion which is usually set for safety on the peripheral portion of the recording paper can be narrowed.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration example of a main part of an image recording apparatus of the present invention.

FIG. 2 is a block diagram showing a configuration example of a control system thereof.

FIG. 3 is a flowchart showing an example of the recording control procedure.

FIG. 4 (a) and FIG. 4 (b) are explanatory views of the effect of the embodiment.

FIG. 5 is a schematic sectional view showing a slave of a conventional image recording apparatus.

[Explanation of symbols]

 1C, 1M, 1Y, Bk Recording head 2 Conveyor belt 3 Head block 4 Sensor 5,6 Registration roller 7,8 Roller 9 Charger 100 Controller 301 Scanner unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location G01B 21/06 7907-2F (72) Inventor Setsu Uchida 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Tohru Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masatoshi Izui 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. In-house (72) Inventor Tatsuo Mitomi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasuyuki Takanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (5)

[Claims] 1. A recording head unit for recording an image on a recording medium, a conveying unit for conveying the recording medium to a recording position by the recording head, and a recording unit arranged in front of the recording position, It is characterized by comprising a detection means for continuously detecting the width of the recording medium in the recording direction by the recording head, and a means for controlling the recording operation of the recording head in accordance with the detected width. Image recording device. 2. The image recording apparatus according to claim 1, wherein the detection unit is a long optical sensor extending in the width direction. 3. The image recording apparatus according to claim 1, wherein the detection unit is an optical sensor divided into a plurality in the width direction. 4. The image recording apparatus according to claim 1, wherein the recording head is an ink jet recording head that performs recording by ejecting ink onto the recording medium. 5. The ink jet recording head has an electrothermal conversion element for generating heat energy that causes film boiling in the ink as energy used for ejecting the ink. The image recording apparatus described in 1.