JPH08224895A - Ink jet recorder - Google Patents

Abstract

PURPOSE: To conduct the recovering operation without contaminating a conveying roller and a recording medium even in the state that the medium is disposed at a recording position. CONSTITUTION: The driving force to a recovering unit is transmitted from an LF motor gear 24 fixed to the output shaft of an LF motor as the drive source of a conveying roller 6 via an LF double gear 25, an LF gear 21, a trigger gear 20, a pump gear 22 and a cylinder gear 23. In this case, the gear 20 is laterally movably installed on the roller 6. A gear lack part 22c is provided at the part of the gear engaged with the gear 21 at the gear 22.

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 which requires recovery driving during recording.

[0002]

2. Description of the Related Art A recording device having functions such as a printer, a copying machine and a facsimile, or a recording device used as an output device of a composite type electronic device including a computer, a word processor, etc. An image is recorded on a recording material (recording medium) such as a plastic thin plate. These recording devices are ink jet type,
It can be classified into a wire dot type, a thermal type, a laser beam type and the like.

Generally, in a serial type recording apparatus which employs a serial scan system in which main scanning is performed in a direction substantially perpendicular to a conveying direction (sub-scanning direction) of a recording material, the recording material is at a predetermined recording position. After being set to, the carriage carrying the recording head, which is a recording means, moves on the recording material to record an image on the recording material in the main scanning direction.

When the recording of one line is completed, a predetermined amount of paper is fed (pitch conveyance), and then the image of the next line is recorded on the stopped recording material in the main scanning direction. To be done.

By repeating the above-mentioned operation, recording is performed on the entire recording material.

Among the recording devices, an inkjet recording device (inkjet recording device) in which recording is performed by ejecting ink from a recording head, which is a recording means, onto a recording material has the following advantages. There is.

(1) It is easy to make the recording means compact.

(2) High-definition images can be recorded at high speed.

(3) It is possible to record on plain paper without requiring special processing.

(4) The running cost is low.

(5) Since it is a non-impact system, it produces less noise.

(6) It is easy to record a color image using multicolor inks.

Among the above-mentioned ink jet recording apparatuses, an ink jet type recording means (recording head) for ejecting ink by utilizing thermal energy is subjected to a semiconductor manufacturing process such as edging, evaporation and sputtering,
By forming the electrothermal converter formed on the substrate, the electrode, the liquid passage wall, the top plate, etc., it is possible to easily manufacture those having a high-density liquid passage arrangement (discharge outlet arrangement),
Further compactness can be achieved.

On the other hand, there are various requirements for the material of the recording material, and in recent years, perforated continuous paper or paper of any shape can be used in addition to the normal recording material, that is, the sheet. Has come to be required.

FIG. 4 is a diagram showing a general configuration example of an ink jet recording apparatus.

The ink jet recording apparatus shown in FIG. 4 has a pickup roller 9 for feeding the recording medium P, a conveying roller 6 and a pinch roller 7, a recording head 1 for recording on the recording medium P, and a recording head. Both ends are fixed to a carriage 2 on which 1 is mounted and a frame 4, and the carriage 2 is slidably supported in a direction orthogonal to the conveyance direction of the recording medium P and in a direction parallel to the surface of the recording medium P. At least a guide shaft 5 and a guide rail 12, a carriage drive belt 11 for reciprocating the carriage 2 in a linear direction, a carriage drive motor 10 and a drive pulley 13, a pressure plate 8 and a base 14 are provided.

The recording head 1 is a replaceable ink jet recording head which is constructed integrally with or separably from an ink tank, has an electric heat exchanger, and grows and contracts bubbles due to film boiling caused by applied heat energy. The recording is performed by ejecting the ink from the ejection port by utilizing the pressure change caused by.

The pinch roller 7 is pressed against the conveying roller 6 by being urged by a spring (not shown) to generate a conveying force for the recording medium P.

A wiper 18 for cleaning and capping, which is a recovery device for the recording head 1, and a cap 17 are provided outside the recording area, and a conveying motor (not shown) is provided at one end of the conveying roller 6. An LF gear 21 for transmitting the power of the LF gear 21 to the transport roller 6, and a trigger gear 20 and a pump gear 22 for transmitting the power from the LF gear 21 to the recovery device.

The printing operation on the recording medium P with the above configuration will be described below.

The recording medium P before printing is mounted on the pressure plate 8,
The pressure plate 8 is separated from the pickup roller 9 by a release cam (not shown) provided on the shaft on which the pickup roller 9 is mounted.

When the recording medium P is set, the conveying roller 6
Is transmitted to the pickup roller 9 and the release cam by a gear (not shown), the release cam separates from the pressure plate 8 and the pressure plate 8 rises, the pickup roller 9 and the recording medium P come into contact with each other, and the pickup roller 9 rotates. Along with this, the recording medium P is drawn and sent to a position facing the ink ejection surface of the recording head 1. Therefore, the carriage drive belt 1 is driven by driving the carriage drive motor 10.
1 rotates, and the carriage 2 reciprocates linearly along the guide shaft 5 and the guide rail 12. At the same time, ink is ejected from the recording head 1 mounted on the carriage 2 in accordance with a recording signal, so that the content to be recorded on the recording medium P is recorded.

Whether or not the recording medium P has reached the conveying roller 6 is normally judged by whether or not the conveying roller 6 has passed the PE sensor by providing a PE sensor (not shown).

When foreign matter such as paper dust or dust adheres to the ink ejection portion of the recording head 1 or the ink in the ejection portion dries and thickens or sticks, clogging occurs in the ejection port and ejection failure ( (Including non-ejection). Therefore, in order to prevent clogging, the ink ejection port of the recording head 1 is sealed with the cap 17 at the time of non-recording, and
A recovery device is used in which ink is sucked from the discharge port through the cap 17 by a suction means such as a pump (not shown) to normalize the discharge port. In the serial type ink jet recording apparatus, the sealing operation (cap operation) by the cap 17 is
This is performed by moving the recording head 1 to a capping position provided outside the recording area and bringing the cap 17 and the ink ejecting portion into contact with each other at the capping position. Here, the drive source for the contact, separation, and suction operations of the cap 17 and the ink ejection portion of the recording head 1 in this configuration is the same as the drive source for rotating the transport roller 6.

FIG. 2 is a schematic diagram for explaining the recording medium conveying drive at the time of recording in the conventional inkjet recording apparatus, and FIG. 3 describes the recording medium conveying drive at the time of recovery driving in the conventional inkjet recording apparatus. It is a schematic diagram for doing.

In the configuration shown in FIG. 2, the driving force is transmitted to the recovery device (not shown) from the LF motor gear 240 fixed to the output shaft of the LF motor (not shown) which is the driving source of the conveying roller 60. Double gear 250, LF gear 21
0, trigger gear 200, pump gear 220 and cylinder gear 230. Here, the trigger gear 200 is installed so as to be movable left and right on the transport roller 60.

Since the gear part of the pump gear 220 that meshes with the LF gear 210 is provided with a toothless portion 220c, the driving force of the LF gear 210 is normally the pump gear 22.
Not transmitted to 0.

When the carriage 2 (see FIG. 4) moves and the trigger gear 200 moves toward the LF gear 210 and is pressed against the LF gear 210, the LF gear 210 is pressed.
The driving force of the LF gear 210 is transmitted to the trigger gear 200 by a clutch structure formed between the trigger gear 200 and the trigger gear 200. At this time, the gear phases of the LF gear 210 and the trigger gear 200 are configured to match.

The driving force transmitted to the trigger gear 200 rotates the pump gear 220 by an auxiliary gear (not shown) provided on the side of the toothless portion 220c of the pump gear 220, and then the LF gear 200 and the pump gear 220. It is transmitted by meshing (see FIG. 3).

The carriage 2 (see FIG. 4) moves again,
When the pressing of the trigger gear 200 against the LF gear 210 is released, the LF gear 210 causes the trigger gear 20 to move.
The transmission of the driving force to 0 is released.

Further, the transmission of the driving force to the recovery device is released by
The LF gear 210 is rotated in the opposite direction to the previous rotation, and the position of the toothless portion 220c of the pump gear 220 is set to the LF gear 21.
It is achieved by returning to a position where it does not mesh with 0.

Further, in the above ink jet recording apparatus,
A cleaning unit is provided for removing foreign matter adhering to the ink ejection portion (ejection port forming surface) of the recording head. As an example of this cleaning means, a mechanism is used that wipes and cleans the ejection port forming surface of the recording head with a flexible wiper (wiping member).

[0033]

However, in the above-mentioned ink jet recording apparatus having the constitution in which the recovery device and the driving source of the conveying roller are the same and the conveying roller is rotated in association with the driving of the recovery device, If the recovery device is actuated during the recording, the transport roller rotates to drive the recovery device, and the recording medium also moves at the same time.
In addition, the rotation direction of the transport roller during recovery drive is opposite to the rotation direction in which the recording medium is ejected, and the recording medium is transported before the recovery device is driven while the recovery device is being driven. In the configuration that is returned from the set position,
The area recorded on the recording medium comes into contact with the transport roller.

The above-mentioned problems will be described in detail below with reference to FIGS. 2 and 3.

The solid line arrows in the figure indicate the rotation direction of each gear during recording, and the broken line arrow indicates the rotation direction of each gear during recovery drive. The left side of the drawing is the paper discharge direction.

As shown in FIG. 2, in this configuration, the rotation of the LF gear 210 during recording is opposite to that during recovery driving.

In FIG. 2, when the recovery device is driven,
Since the LF gear 210 rotates in the opposite direction to that during recording (in the direction of the broken line arrow), the transport roller 60 press-fitted into the LF gear 210 also rotates in the opposite direction to that during recording. The recording medium P is conveyed in the direction opposite to that at the time of recording by the conveying force of the conveying roller 60. Therefore, the recording start position P ₀ shown in FIG. 2 is returned to the position P ₀ shown in FIG.

By the above-described operation, the ink ejected on the recording medium P is transferred to the conveying roller 60, and the recording medium (including the recording medium to be conveyed next) is contaminated. .

Further, since the coefficient of friction of the transport roller 60 is lowered by the ink transferred to the transport roller 60, there is a possibility that the transport failure of the recording medium may occur due to the reduction of the transport force.

The present invention has been made in view of the problems of the above-described conventional techniques, and even when the recording medium is at the recording position, the recovery operation can be performed without contaminating the conveying roller or the recording medium. It is an object of the present invention to provide an inkjet recording device that can perform the operations.

[0041]

In order to achieve the above-mentioned object, the present invention provides a conveying roller for conveying a recording medium to a recording start position, a conveying roller driving means for rotating the conveying roller, and the recording head. Recovery drive means for performing the recovery drive of the conveyance roller and the same drive source as the drive source, and the rotation directions of the drive source at the time of recording on the recording medium and at the time of the recovery drive are opposite directions. In the ink jet recording apparatus, the recovery drive means, when performing recovery drive, rotates the transport roller in a rotation direction at the time of recording more than a maximum rotation amount of rotation of the transport roller during recovery drive performed thereafter. Characterize.

Further, the recovery drive means rotates the carry roller by a difference between the amount of rotation of the carry roller during the recovery drive and the amount of rotation of the carry roller at the start of the recovery drive after the recovery drive is completed. It is characterized by

Further, the recording head is provided with an electrothermal converter for generating thermal energy for ejecting ink.

Further, the recording head is characterized in that the ink is ejected from the ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter.

[0045]

According to the present invention having the above-described structure, when the recovery drive is performed, the transport roller rotates in the rotation direction at the time of recording and more than the maximum amount of rotation of the transport roller during the recovery drive performed thereafter. Therefore, even if the recording medium is conveyed in the direction opposite to the paper discharge direction by the reverse rotation of the conveying roller due to the recovery drive, the conveying roller does not come into contact with the recorded area on the recording medium. The medium does not get dirty.

Further, after the recovery drive is completed, accurate recording can be performed by rotating the transport roller by the difference between the rotation amount of the transport roller actually rotated during the recovery drive and the rotation amount of the transport roller at the start of the recovery drive. The starting position is maintained.

[0047]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram for explaining a recording medium conveyance drive at the time of recording and recovery drive in an ink jet recording apparatus when an embodiment of the present invention is adopted.

In the structure shown in FIG. 1, the driving force is transmitted to the recovery device (not shown) from the LF motor gear 24 fixed to the output shaft of the LF motor (not shown) which is the driving source of the conveying roller 6. Double gear 25, LF gear 21, trigger gear 20, pump gear 22 and cylinder gear 2
3 through 3. Here, the trigger gear 20 is installed so as to be movable left and right on the transport roller 6.

Since the pump gear 22 is provided with a toothless portion 22c at a part of the gear that meshes with the LF gear 21, the driving force of the LF gear 21 is not normally transmitted to the pump gear 22.

When a recovery device (not shown) is driven during recording on the recording medium P, first, the maximum amount of return d of the recording medium P at the time of recovery drive in the sheet discharge direction of the recording medium P by the conveying roller 6. The above is conveyed. That is, the recording start position P ₀ of the recording medium P is conveyed so as to move to the pre-recovery drive recording start position P ′ ₀ .

After that, when the recovery device is driven, the LF gear 21 rotates in the opposite direction to the recording at the time of the recovery drive (in the direction of the broken line arrow), so that the conveying roller 6 press-fitted into the LF gear 21 also does not record. Rotate in reverse. Therefore, the recording medium P is conveyed in the opposite direction to that at the time of recording by the conveying force of the conveying roller 6, and at the end of the recovery drive, the recording start position that has moved to the pre-recovery drive recording start position P ′ ₀ is the original. Position P
_{The value} is returned to _0, and the recording is started from the recording start position P ₀ .

If the amount of movement due to the recovery drive is equal to or greater than the preset maximum return amount d of the recording medium P during the recovery drive, the maximum return of the recording medium P during the recovery drive is performed before the start of recording. The conveyance roller 6 rotates in the recording rotation direction by the difference between the amount d and the actual movement amount, whereby the recording medium P returns to the recording start position and recording is started.

In the above-described embodiment, the present invention has been described using the printer in which the ink jet recording head is mounted on the carriage. The configuration described in the present invention is preferably used even for an information processing apparatus that includes a scanner unit that is compatible with a recording head and that can be mounted on a carriage, and that can read image information from a document sheet supported by a platen. You can INDUSTRIAL APPLICABILITY The present invention brings excellent effects particularly in an ink jet type recording head and a recording apparatus which perform recording by forming flying droplets by utilizing thermal energy among the ink jet recording systems.

With regard to its typical structure and principle, for example, US Pat. Nos. 4,723,129 and 4740 are applicable.
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 liquid path in which is stored, 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 the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected.

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 of 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 passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region.

In addition, Japanese Patent Application Laid-Open No. 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. The present invention is also effective as a configuration based on Japanese Patent Application Laid-Open No. 59-138461, which discloses a configuration in which an opening corresponds to a discharge portion.

Further, as a full line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length can be increased by combining a plurality of recording heads as disclosed in the above-mentioned specification. The present invention can exert the above-mentioned effects more effectively, although it may have a configuration that satisfies the above requirement or a configuration as one recording head integrally formed.

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. The present invention is also effective when a cartridge-type recording head provided with an ink tank is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a constitution of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. If you list these specifically,
Capping means, wiping member, pressurizing or sucking means for the recording head, preheating means by an electrothermal converter or another heating element or a combination thereof, and a preliminary ejection mode for performing ejection other than recording It is also effective to perform stable recording.

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. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In the embodiment of the present invention described above,
Although the ink is described as a liquid, it is an ink that solidifies at room temperature or lower and softens at room temperature, or is a liquid, or the ink itself is 30 ° C. or higher and 70 ° C. or lower in the above-mentioned inkjet method. Since the temperature is generally adjusted within the range to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range, it is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy for the state change of the ink from the solid state to the liquid state, or the ink is solidified in the standing state for the purpose of preventing the 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. Also good. 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 a form of the recording apparatus according to the present invention, in addition to a recording apparatus integrally or separately provided as an image output terminal of information processing equipment such as a word processor and a computer, a copying apparatus combined with a reader, and It may take the form of a facsimile machine having a transmission / reception function.

[0066]

Since the present invention is constructed as described above, it has the following effects.

According to the first aspect of the present invention, when the recovery drive means performs the recovery drive, the maximum rotation amount by which the carry roller rotates in the rotation direction at the time of recording and during the subsequent recovery drive. When the recording medium is at the recording position, the recording medium is recorded on the recording medium even if the recording medium is conveyed in the direction opposite to the paper discharge direction by the reverse rotation of the conveying roller due to the recovery drive. The conveyance roller does not come into contact with the area, and the recovery drive can be performed without causing the recording medium to be contaminated.

According to a second aspect of the present invention, the recovery driving means sets the rotation amount of the transport roller rotated during the recovery drive after the completion of the recovery drive and the rotation amount of the transport roller at the start of the recovery drive. Since the transport roller is rotated by the difference,
An accurate recording start position can be maintained.

According to the third aspect of the invention, since the recording head is provided with the electrothermal converter for generating thermal energy for ejecting ink, it is possible to eject ink with excellent responsiveness.

According to the fourth aspect of the invention, the recording head has a function of ejecting the ink from the ejection port by utilizing the film boiling generated in the ink by the thermal energy applied by the electrothermal converter. The same operation as in item 3 is performed.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining a recording medium conveyance drive at the time of recording and recovery drive in an inkjet recording apparatus when an embodiment of the present invention is adopted.

FIG. 2 is a schematic diagram for explaining a recording medium conveyance drive during recording in a conventional inkjet recording apparatus.

FIG. 3 is a schematic diagram for explaining a recording medium conveyance drive during recovery drive in a conventional inkjet recording apparatus.

FIG. 4 is a diagram showing a general configuration example of an inkjet recording apparatus.

[Explanation of symbols]

1 Recording Head 2 Carriage 4 Frame 5 Guide Shaft 6 Conveyor Roller 7 Pinch Roller 8 Pressure Plate 9 Pickup Roller 10 Carriage Drive Motor 11 Carriage Drive Belt 12 Guide Rail 13 Drive Pulley 14 Base 17 Cap 18 Wiper 20 Trigger Gear 21 LF Gear 22 Pump Gear 22c Missing teeth 23 Cylinder gear 24 LF Motor gear 25 LF Double gear P Recording medium P ₀ Recording start position P ′ ₀ Recording start position before recovery drive d Maximum return amount of recording medium during recovery drive

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical display location B41J 23/02 (72) Inventor Takashi Nojima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Company (72) Inventor Takeshi Iwasaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Soichi Hiramatsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) ) Inventor Hitoshi Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hiroyuki Inoue 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A transport roller for transporting a recording medium to a recording start position and a transport roller drive unit for rotating the transport roller; and a recovery roller for the recording head, the transport roller drive unit and a drive source. In an inkjet recording apparatus having the same recovery driving means, wherein the direction of rotation of a drive source during recording on the recording medium and that during recovery driving are opposite to each other, the recovery driving means performs recovery driving. In some cases, the ink jet recording apparatus is characterized in that the conveying roller is rotated in a rotation direction at the time of recording more than a maximum amount of rotation of the conveying roller during a recovery drive performed thereafter. 2. The ink jet recording apparatus according to claim 1, wherein the recovery drive unit rotates the amount of rotation of the transport roller during recovery drive after completion of the recovery drive, and the transport roller at the start of the recovery drive. An ink jet recording apparatus, wherein the conveying roller is rotated by a difference from a rotation amount. 3. The inkjet recording apparatus according to claim 1 or 2, wherein the recording head includes an electrothermal converter for generating thermal energy for ejecting ink. Recording device. 4. The ink jet recording apparatus according to claim 3, wherein the recording head ejects the ink from an ejection port by utilizing film boiling generated in the ink by thermal energy applied by the electrothermal converter. An ink jet recording apparatus characterized by the above.