JP2728914B2 - Ink jet recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is used as an ink jet recording apparatus having functions such as a facsimile, a copying machine, a printer, and the like, and as an output device such as a multifunction machine having the functions and a work station. The present invention relates to an ink jet recording apparatus.

[Conventional technology]

The non-impact recording method has recently attracted attention in that the generation of noise during recording is extremely small to a negligible level. Among them, there is a possibility of high-speed recording, and an ink jet recording method capable of performing recording on so-called plain paper without requiring a specific fixing process is an extremely effective recording method.

The recording head applied to the ink jet recording apparatus is:
In general, there are provided a fine liquid discharge port (orifice), a liquid path, an energy action section provided in a part of the liquid path, and energy generating means for generating droplet forming energy to act on the liquid in the action section. .

A recording method using an electromechanical transducer such as a piezo element as an energy generating means for generating such energy irradiates an electromagnetic wave such as a laser or the like, absorbs the liquid therein to generate heat, and generates heat. Recording method using energy generating means for ejecting and flying droplets by action,
Alternatively, there is a recording method using an energy generating means for discharging the liquid by heating the liquid with an electrothermal converter such as a heating element having a heating resistor. Among them, a recording head used in an ink jet recording method in which a liquid is ejected by thermal energy has a high density of liquid ejection ports (orifices) for ejecting a recording droplet and forming a flying droplet. This makes it possible to record at a high resolution. Among them, a recording head using an electrothermal transducer as a means for generating thermal energy can easily be made compact as a recording head as a whole. It is possible to make full use of the advantages of the processing technology, and it is easy to make it multi-nozzle and high-density mounting because it is easy to make it longer and more planar (two-dimensional). It is possible to provide an ink jet recording head and an apparatus having the head, which are inexpensive to manufacture.

In this manner, the recording head for an ink jet manufactured using a semiconductor manufacturing process using an electrothermal converter as the energy generating means generally has liquid paths corresponding to each orifice, and fills each liquid path with the liquid path. An electrothermal converter is provided as means for applying thermal energy to the liquid and discharging the liquid from a corresponding orifice to form a flying droplet. In addition, the liquid paths are configured such that liquid is supplied from a common liquid chamber communicating with each liquid path.

FIG. 17 is a schematic configuration diagram of such an ink jet recording head, which has undergone semiconductor manufacturing process steps such as etching, vapor deposition, and sputtering, and has been formed into a film on a substrate 1102 by an electrothermal converter 1103, an electrode 1104, and a liquid. Road wall 1105, top plate 11
The ink jet recording head consisting of 06 is shown. The recording liquid 1112 is supplied from a liquid storage chamber (not shown) through a liquid supply pipe 1107 to a common liquid chamber of the recording head 1101.
Supplied in 1108. In the figure, reference numeral 1109 denotes a liquid supply pipe connector. The liquid 1112 supplied into the common liquid chamber 1108 is supplied into the liquid passage 1110 by a so-called capillary phenomenon, and is stably held by forming a meniscus at the discharge port surface (orifice surface) at the leading end of the liquid passage. Here, by energizing the electrothermal converter 1103, the liquid on the electrothermal converter surface is heated rapidly, bubbles are generated in the liquid path, and the liquid is discharged from the discharge port 1111 by expansion and contraction of the bubbles. Droplets are formed. With the above-mentioned configuration, a multi-nozzle ink jet recording having 128 or 256 discharge ports in a high-density discharge port arrangement such as a discharge port density of 16 nozzles / mm, and further having discharge ports arranged over the entire recording width. A head can be formed.

FIG. 18 is a schematic perspective view showing a configuration example of an ink jet recording apparatus in which the above-described ink jet recording head is actually arranged in the recording apparatus. In the figure, a recording head 1101 similar to the recording head described above is reciprocated on a rail 1213a by driving a motor 1216.
4 and integrated. Ink tank 1222Y, 1222
M, 1222C, 1222B are pumped by inks 1223Y, 1222
The recording head 1101 is supplied by 3M, 1223C and 1223B.
The recording member (recording paper) is conveyed along the platen roller 1212 and temporarily stops. And the recording head 1101 is a rail
Image recording is performed by ejecting ink while moving forward along 1213a and 1213b. When image recording for a predetermined paper width is performed, the recording head 1101 moves again along the rails 1213a and 1213b and returns to the home position.
It is conveyed by the desired amount according to 1212 and stops again. Then, the image recording is performed by repeating such an operation.

The recording method of performing printing while reciprocating the recording head on the stopped recording paper is hereinafter referred to as a serial scan method.

[Problems to be solved by the invention]

However, the recording head is multi-orifice,
When the recording paper is elongated to have substantially the same width as the recording paper, the recording method is completely different from the conventional serial scan method. For this reason, various problems different from those of the conventional serial scan type recording apparatus occur. Above all, regarding the head recovery operation (recovery system) that greatly affects image quality, reliability, durability, and life, etc., especially in a multi-nozzle type having a longer length, the absolute number of discharge ports increases. Stable discharge from all discharge ports, prevention of non-discharge, etc. become important. Therefore, the performance of the recovery system is so important as to determine the performance of the entire apparatus.

Therefore, the present invention solves the problem of affecting the performance of the recovery system when configuring an ink jet recording apparatus using a recording head that is multi-nozzle and is long enough to cover the recording paper width, and achieves high image quality. It is an object of the present invention to provide a highly reliable ink jet recording apparatus which can be obtained for a long period of time.

[Means for solving the problem]

An inkjet recording apparatus of the present invention includes: an inkjet head provided with a plurality of ejection openings for ejecting ink to perform recording on a recording material; a head holding unit for holding the inkjet head; A head recovery unit for recovering the ejection port in a state, a recording position where the ejection port faces the recording material and recording is performed, and the ejection port faces the head recovery unit to perform recovery. A head moving unit for moving the ink jet head to a recovery position, a head retreat unit facing an ejection port and a recovery retreat position where the head recovery unit retreats away from the ink jet head. Recovery moving means for moving the head recovery means, the inkjet head, the head holding means, and the head. Anda housing for holding integrally with said recovery moving means and recovery means and said head moving means, the housing is characterized by detachable from the apparatus main body.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic sectional view of an ink jet recording apparatus for explaining an embodiment of the present invention. First, the outline of the ink jet recording apparatus of the present embodiment will be described with reference to FIG. In the figure, reference numeral 301 denotes a scanner which reads a document and converts it into an electric signal. Then, a signal based on the converted signal is sent to a recording head unit 305 of the printer unit 302.
As a drive signal. The recording paper as one of the recording members stored in the paper feeding unit 303 is sent to the belt transport unit 304 one by one as needed. When the recording paper passes through the belt transport unit 304, the recording head unit 305
The image is recorded by the
Sent to 20. Reference numeral 306 denotes a recovery cap unit, which has a function of keeping the recording head unit 305 in a printable state at all times. Hereinafter, each of the above configurations will be described in detail.

First, the supply of ink to the full-lined long recording head used in this embodiment will be described with reference to FIG. FIG. 16 is an explanatory view schematically showing the configuration of the long recording head and the ink supply means, wherein 1601 is the recording head, 1652 is a common liquid chamber in the recording head 1601, and 1653 is a recording liquid ejection surface. A discharge port for liquid discharge arranged in 1654. Thus, the number of the ejection ports 1653 of the present embodiment is arranged over the entire recordable width of the target recording material,
The recording liquid can be discharged by selectively driving a heating element provided in a liquid path (not shown) leading to each of the discharge ports 1653, and printing can be performed without moving and scanning the head itself.

1655 is a recording liquid supply tank for supplying the recording liquid to the recording head 1601, and 1656 is a main tank for replenishing the recording liquid to the supply tank 1655.The recording liquid is supplied to the recording head 1601 from the supply tank 1655 by a supply pipe 1657. To room 1652,
In addition, at the time of replenishment of the recording liquid, the recording liquid can be replenished from the main tank 1656 to the supply tank 1655 by the recovery pump 1659 via the one-way replenishment rectifying valve 1658. Also, 16
Reference numeral 60 denotes a one-way rectifying valve for recovery used for the recovery operation performed for recovering the discharge function of the recording head 1601, 1661 denotes a circulation pipe in which the recovery rectifying valve 1660 is interposed, and
Reference numeral 1662 denotes an electromagnetic valve interposed in the first supply pipe 1657 described above, and reference numeral 1663 denotes an air vent valve for the supply tank.

In the recording head 1601 configured as described above and its recording supply system and recovery system, when recording is performed, the solenoid valve 1662 is kept open, and the recording liquid is supplied from the supply tank 1655 due to its own weight. The liquid is supplied to the chamber 1652, and is guided from the liquid chamber 1652 to the discharge port 1563 via a liquid path (not shown). In addition, during the recovery operation performed to cool the recording head 1601 together with the removal of air bubbles remaining in the common liquid chamber 1652 and the supply system,
By driving the recovery pump 1659, the recording liquid is sent to the common liquid chamber 1652 by the circulation pipe 1661, and the first liquid is supplied from the common liquid chamber 1652 to the first supply pipe.
By 1657, the recording liquid can be returned to the supply tank 1655 and circulated. Further, at the time of initial filling of the liquid path and the like, the circulation pipe 1661 is pumped by the pump 1659 with the electromagnetic valve 1662 closed.
After that, the recording liquid can be pressure-fed to the common liquid chamber 1652, and the recording liquid can be discharged from the discharge port 1653 together with the discharge of the bubbles.

Normally, such a recording head is left without ink inside the ink ejection port at the time of non-recording. A capping means having a cap which can be joined to the ejection port surface or ejection port surface side of the recording head is provided, and when the recording is not performed, the cap is joined to the recording head, so that the recording head is covered with a lid. From the atmosphere, and fill the air layer of the joint portion with the vapor of the ink to make the space formed by the cap and the recording head a saturated vapor pressure of the ink, thereby evaporating the ink liquid in the liquid path and accompanying it. Prevents increase in viscosity and drying of ink in the liquid path. However, in a low-humidity environment or when recording is to be suspended for a long period of time, the viscosity of the ink may increase even if the above-described capping is performed to prevent the evaporation of the ink liquid in the liquid path. In some cases, it is not possible to prevent non-ejection or unstable ejection of ink from the ejection openings during printing after the printing suspension period. In the present invention, the problem of whether or not ink is ejected for the first time after a pause is hereinafter referred to as a “first problem”. To solve this problem, as described above, the recovery pump 1659 is driven to circulate and pressurize the ink, and the ink is circulated and pressurized so as to discharge the ink from all the ejection openings of the recording head. I have. When the above-mentioned state of non-discharge is slight, the entire head energy generating means is driven to perform an ink discharge operation similar to that for recording on paper or the like. This is not ejection for performing image recording, and is hereinafter referred to as “idle ejection” in the present invention.

As described above, when the ink dries due to a long non-recording leaving state and the viscosity increases and the inside of the discharge port and / or the liquid path is stuck, the non-recording state is changed by the pressurized circulation of the ink. In a relatively short time, the heads are rotated in such a manner that they can be printed and recorded by the idle discharge operation for those having a small fixed state.

A recording member suitably used in this embodiment will be described.

In the ink jet recording method, small droplets of a recording liquid called ink are ejected, and the droplets are adhered to a recording paper surface such as paper to perform recording. It is necessary not to be blurred. or,
The ink adhering to the recording member is quickly absorbed into the inside of the recording member. In particular, even when inks of different colors adhere to the same portion in a short time, there is no phenomenon of ink bleeding or bleeding. It is preferable that the spread of the image is suppressed so that the sharpness of the image quality is not impaired. In some cases, these characteristics are not sufficiently satisfied with copy paper called plain paper used in an electrophotographic copying machine or the like or other general recording paper. In these papers, printing with only one color or superimposing two colors can often provide a satisfactory image quality to some extent. For example, when printing a full-color image by superimposing inks of three or more colors, as in the case of printing and recording, When the amount of ink adhering to the paper increases, a satisfactory image quality record may not be obtained.

In the ink jet recording apparatus of the present embodiment as a sheet satisfying the above-mentioned characteristics, a coating (for example, finely divided silica) which can obtain the above-mentioned characteristics on a base paper as disclosed in JP-A-56-14883. It is preferable to use a recording member to which is applied. The ink is deposited on the coating surface of the recording member. Therefore, in the present embodiment, when performing image recording using three or more colors of ink for higher quality image recording, the recording paper, one color or two colors is used.
When image recording is performed using color inks, non-coated paper (paper not coated above) is selected and used. However, it does not matter if an image is recorded using one or two colors of ink on coated paper.

In the scanner section 301, reference numeral 401 denotes a document, and 402 denotes a document scanning unit for scanning the document. Document Scanning Unit 402
Has a built-in rod eye rains 403 and a 1: 1 magnification type color separation line sensor (color image sensor) 404 and an exposure means 405. When at least the original scanning unit 402 moves and scans in the direction of arrow A to read the image of the original 401 on the original platen, the exposure lamp in the exposure unit 405 in the original scanning unit 402 is turned on, and the reflected light from the original 401 is turned on. Is led by a rod array lens 403 and condensed on a 1: 1 type color separation line sensor (hereinafter referred to as a reading sensor) 404 which is a reading sensor for color information, and reads color image information of a document for each color. Convert to digital signal. This digital signal is sent to the printer unit 302. A drive signal based on these signals is supplied to the recording head for each color, and the liquid is ejected.

2 (a) and 2 (b) are schematic cross-sectional views of a main part of a printer unit in the ink jet recording apparatus according to the present invention. The state during the recovery operation of the recording head will be described with reference to FIG. 1C, 1M, 1Y, 1Bk
These are ink jet recording heads to which inks of cyan, magenta, yellow, and black are supplied, respectively. Each head is precisely fixed to the head block 6, and the parallelism of each head, the distance between the heads, and the like are ensured within desired accuracy. Head of each of these colors
In the vicinity of the discharge ports of 1C, 1M, 1Y, and 1Bk, ink absorbers for absorbing ink corresponding to the discharge ports of each head, 3C, 3
M, 3Y, 3Bk are provided. Ink absorbers 3C, 3M, 3Y, 3Bk
Are supported by the absorber guide 7 so as to be able to approach and separate from the ejection surfaces of the recording heads 1C, 1M, 1Y, and 1Bk. The ink absorbers 3C and 3Y in FIG.
1 and 1Y are separated from the ejection surface. The ink absorbers 3M and 3Bk are shown in contact with the ejection surfaces of the recording heads 1M and 1Bk. An ink partition plate 8 is provided between the ink absorbers. An ink seal 4 is provided between each partition plate 8 and the head block 6, and seals ink between colors. Also, in the vicinity of each ink absorber,
An ink squeezing member 5 is provided, and the ink absorbed by the ink absorbers 3C, 3M, 3Y, and 3Bk can be squeezed out and dropped by a lever (not shown). FIG. 2 (a) shows a state in which the ink absorber 3Y of the yellow head 1Y is squeezed.

The head block 6 to which the recording heads 1C, 1M, 1Y, and 1Bk are fixed is inserted into the block stay 9 via a rail 15 so as to be freely inserted and removed. The block stay 9 is rotatable about the rotation center N as an integral part of the head block 7 and the heads of the respective colors. The recovery system container 2 can be moved from the recovery operation state in FIG. 2A to a retreat position indicated by a two-dot chain line by a moving mechanism (not shown). At the bottom of the recovery container 2, an ink discharge port 13 is provided, which is ejected from the recording heads 1C, 1M, 1Y, 1Bk and absorbed and collected by the ink absorbers 3C, 3M, 3Y, 3Bk. The discharged ink is guided to a discharge ink tank (not shown) via a discharge ink hose (not shown).

FIG. 2B is a schematic cross-sectional view of a principal part showing a state of the recording head when recording an image. From the state of FIG.
After the recovery system container 2 has been moved to the retracted position (after being moved to the position indicated by the two-dot chain line in FIG. 2A), the recording head is rotated to the horizontal position as shown in FIG. 2B. is there. In this state, ink is ejected based on the image recording signal of each head, and an image is formed on recording paper conveyed at a desired distance from the ejection surface P of the recording head.

FIGS. 3 (a) and 3 (b) show the recording head,
FIG. 3A is a schematic top view, and FIG. 3B is a schematic side view, for explaining a positioning and fixing portion. In FIG. 3 (a), reference numerals 20 and 21 denote head fixing members, and the abutting portions 1a at both ends of the head 1 are inserted into the abutting portions of the fixing members 20 and 21, respectively. ) In the directions of arrows A and B, and the position in the vertical direction (the direction of arrow C in FIG.
Determined by 18,19. Reference numeral 22 denotes a pressing pin, which holds the head inserted into the head fixing members 20 and 21 in the abutting portion 2.
The positioning and fixing are achieved by bringing the springs 23 into contact with the pins 0a and 21a via the pressing pins 22. Reference numeral 24 denotes an adjusting screw, which is indicated by an arrow A in FIG.
The position of each head can be adjusted in the direction, that is, the direction perpendicular to the paper feeding direction (hereinafter referred to as “left margin”). Reference numeral 25 denotes an eccentric top for adjusting the head inclination direction. In FIG. 3 (a), the position of each head in the direction of arrow B is moved by moving the head abutting portion 1a by the amount of eccentricity generated by rotating the top 25, and each head can be adjusted independently. It is possible.

With the above adjustment mechanism, the adjustment of the mounting position of each head can be easily performed. Therefore, it is easy to correct the deviation of the image drawn in each color and record a higher quality image.

Next, the mechanism for moving the head will be described with reference to the schematic cross-sectional views of the main part of the printer unit shown in FIGS. 4 (b) and 4 (b). FIGS. 4 (a) and 4 (b) show the printer section viewed from the opposite side to FIGS. 3 (a) and 3 (b), respectively. Reference numeral 26 denotes a head unit drive motor, and the drive of this motor is transmitted to a head frame 28 via a gear 27. Head frame 28
Can rotate in the direction of the arrow in FIG. Further, the head frame 28 is provided with a rail 29 for inserting and removing a head block.
Can be taken out and replaced integrally with each recording head 1. The head block 6 is removed and inserted at a position where the head frame 28 overlaps a notch (not shown) provided in a part of the unit front side plate. The stop position of the head frame 28 is a recovery position, a printing position, a retreat position (head retreat position),
There are four positions for the head unit attachment / detachment position. 4 (a) and 4 (b) show the recovery position.
The retracted position is the retracted position of the recording head 305 when the recovery container 2 is moved as described later with reference to FIGS. 12B and 12E, and the printing position (recording position) is as shown in FIG. This is the head-down position described later in d). In the present invention, the retracted position and the head unit attaching / detaching position are configured to be the same position. Each of these position detections is accurately performed by the light shielding plate 52 provided on the head frame 28 shielding the detection unit of the sensor 51 disposed corresponding to each stop position.

FIG. 4 (b) shows an example in which a worm speed reducer is used for the drive unit of the above-described head moving mechanism. 59 is worm, 60
Is a worm wheel. Thus, the head frame 28 can be moved only by driving from the motor side due to the characteristics of the worm speed reducer, and the head frame itself falls naturally due to the weight of the plurality of heads mounted in the head frame. There are no accidents
Further, it is possible to fix the position of the head frame at the position where the driving of the motor is stopped.

FIGS. 5 (a) and 5 (b) are schematic side views for explaining a driving mechanism of a head recovery device, and are the same as FIGS. 4 (a) and 4 (b). This shows a state viewed from the side. FIG. 5C is a schematic partial enlarged view of the left side portion of the drive mechanism of the recovery device shown in FIG. 5A as viewed from the back side.

In these figures, reference numeral 30 denotes a recovery device driving motor, and the driving of the motor is transmitted to a driving screw 37 via gear trains 31 to 36. Drive screw 37 is motor 30
The driving force transmitted from the driving screw 37 is converted into linear motion, and the screw nut 38 engaged with the driving screw 37
Moves the recovery container 2 from the recovery position (the position where the head recovery means faces the discharge port), that is, the capping position to the retreat position (recovery retreat position). The nut holder 39 engaged with the screw nut 38 and the recovery container 2 are connected by a connecting pin 40, and the driving of the motor 30 enables the recovery container 2 to reciprocate. Further, two arm portions 41 and 42 are provided on the front and rear side surfaces of the recovery system container 2 respectively.
(The opposite side is not shown) is rotatably supported on the container 2. Roller 45 (the other side is not shown) on the arm 42
Are rotatably supported. On the other hand, a roller 45a (the opposite side is not shown) is provided on a unit side plate 47 (the opposite side is not shown) facing the arm portion 42 of the recovery container 2.
Note that rollers similar to the rollers 45 and 45a are also provided on the arm 41 side. In addition, rails 48 and 49 provided with grooves for fitting into the recovery container 2 when the recovery container 2 reciprocate are provided.
Are provided on both sides. Each of the arm portions 41 and 42 is provided with a torsion coil spring 44 so that each roller is urged against the groove of the rail. The rotational power of the motor 30 is transmitted to the arm portions 41 and 42 via the gear trains 31 to 36, the screw 37, the nut 38, the nut holder 39, and the connecting pin 40, and is converted into the reciprocating motion of the recovery container 2. At this time, arm part 4
Rollers 45, 45a rotatably mounted on 1, 42 are urged along the grooves provided in rails 48, 49 by the repulsive force of torsion coil spring 44, so there is no play along these grooves. Moving. Accordingly, it is possible to cause the recovery container 2 to move with a desired trajectory depending on the shape of the rails 48 and 49. As described above, since a plurality of rollers for moving the container 2 are used for one arm, the load due to the container 2 is dispersed, and therefore, the container 2 can be moved smoothly. Further, since arms and rollers are provided on both sides of the container 2, a single screw used for driving the container 2 can transmit the driving force sufficiently smoothly. The stop position of the recovery container 2 is a recovery position 2a and a retreat position 2b, and each position is a sensor (photo interrupter) in which a light shielding plate 50 attached to a nut holder 39 is arranged corresponding to each stop position. This is done accurately by shielding the 51 detector from light.

Next, a description will be given of a recovery operation mechanism such as capping by capping, idle discharge, and ink pressurization circulation. 6 (a) and 6 (b) are schematic side views for explaining a cap drive section of the recovery device according to the present invention. FIG. 6 (a) shows the state when the absorber is detached from the head discharge surface, and FIG. 6 (b) shows the state when the absorber comes into contact with the head discharge surface. Reference numeral 60 denotes a cap driving motor. The driving of this motor is transmitted to a rack shaft 65 via gear trains 61 to 64, and further, via a member 66, 67, a cap driving slide arm 68.
Is transmitted to This slide arm 68 has a slide pin
It can slide along 72. Slide arm
The reciprocation of 68 is converted into the up and down movement of the absorber guide 7 by the cap up and down rotating arm 69. The ink absorbers guided by the absorber guides 7 are sandwiched by absorber stoppers 71, and slide pins 72 provided at both front and rear ends are vertically moved along guide portions 73a provided on the cap side plate 73. It is configured to be possible. With such a configuration, the driving force of the motor 60 is transmitted as a driving force for performing the operation of contacting and separating the head 1 of the ink absorber 3 from the ejection surface. In addition,
The detection of the position of the separation is performed by detecting the position of the detecting member 65a attached to the rack shaft 65 by the micro switches 80 and 81 provided in the recovery container 2.

Next, one preferred embodiment of the aperture mechanism of the ink absorber in the recovery / cap portion of the present invention will be described. FIGS. 7 (a) and 7 (b) are schematic explanatory views for explaining the ink absorbing member restricting mechanism of the recovery device according to the present invention, and FIG. , FIG. 7 (b)
Indicates the time when the absorber is squeezed. Reference numeral 60 denotes an aperture driving motor, which also serves as the above-described cap driving motor in this embodiment. The driving of the cap mechanism and the diaphragm mechanism is transmitted when the driving is switched by an electromagnetic clutch (not shown). The drive transmitted by the clutch (not shown) is transmitted to the aperture driving cam 79 via gear trains 75 to 78. Here, the rotation of the cam 79 is
Is reciprocated. The slide arm 82 is linearly movable along a slide pin 83 provided on the cap side plate, and is further transmitted to the ink absorber throttle member 5 via the lever 84 to absorb the ink absorber 3. By pressing and deforming to the body guide 7 side, the ink soaked in the ink absorber can be squeezed out and dropped (FIG. 7 (b)). The aperture members of each color are connected by a connecting bar 86, so that the drive from the motor can be transmitted simultaneously for all colors.

In the apparatus of the present embodiment, the aperture mechanism is controlled so that the above-mentioned cap, that is, the ink absorber 3 is separated from the head ejection surface, so that the aperture mechanism operates. This is performed by detecting the rotation of the cam by the switch 87. Normally, one operation is performed by one rotation of the cam, that is, one stop. The ink absorbing body 3 whose ink absorbing power has been increased again by these squeezing operations is again brought into contact with the head ejection surface, and is completely cleaned.

Next, the wiping mechanism for the head ejection surface will be described. FIGS. 8 (a) and 8 (b) are schematic illustrations for explaining the head ejection surface wiping mechanism of the recovery device according to the present invention, and FIG. , FIG. 8 (b)
Indicates a driving time. In this embodiment, a cleaning blade 88 is used for wiping the head ejection surface. Reference numeral 60 denotes a blade drive motor, which is also used as the ink absorber aperture drive motor described above in the present embodiment, and is also driven in sequence in conjunction with the aperture drive. Is not switched. Similarly to the above-described aperture driving, the driving of the motor 60 transmitted to the cam 79 via the gear trains 75 to 78 is transmitted to the blade driving slide arm 90. The slide arm 90 is linearly movable along a slide pin 91 provided on the cap side plate, whereby the blade 88 is further transmitted to a blade rotation arm 92 and mounted on a blade base 93 interlocked therewith. Is rotated about a shaft 94 as a rotation center. Needless to say, the rotation center is provided at a position where the ink droplets and the fixed ink adhering to the head ejection surface or dust can be efficiently wiped. In the apparatus according to the present embodiment, as described above, the driving source is the same as that for driving the ink-absorber diaphragm, and similarly, the blade is driven in a state where the ink-absorber is separated from the head ejection surface. It is configured as follows.
The detection of the blade drive is also performed by the microswitch 87 provided on the cam 79, similarly to the diaphragm drive. In other words, the ink absorber diaphragm drive and the blade drive are simultaneously performed by the drive of the motor 60 in a state where the ink absorber 3 is separated from the head ejection surface.

Next, the recovery operation by the recovery system will be described in more detail.

For the sake of convenience, the recovery operation is divided into three, namely, capping, preliminary (empty) discharge, and ink discharge, and these operations will be described in order.

First, the capping operation will be described. FIG. 9 is a schematic diagram showing a recording head capping state. In this figure, the recording heads 1C, 1M, 1Y, 1Bk arranged side by side in the head block 6 are engaged with a recovery / cap unit 306 as ejection recovery means. The recovery system container 2 includes an ink seal 4, a partition plate 8, and ink absorbers 3C and 3C.
M, 3Y, and 3Bk are provided, and the ink absorber usually has a certain gap from the head ejection surface. This allows
The vicinity of the discharge ports of the recording heads 1C, 1M, 1Y, and 1Bk is surrounded by the ink seal 4, the partition plate 8, and the ink absorbers 3C, 3M, 3Y, and 3Bk to maintain a proper wet state and to dry the head discharge ports. Can be prevented. As described above, the non-discharge of the ink during the suspension of the recording head and the standby state is prevented by the capping, and the discharge port is protected to prevent dust and the like from adhering and entering near the discharge port.

Next, the preliminary (empty) ejection operation will be described. No.
FIG. 10 is a schematic diagram showing the idle discharge operation. In the same manner as the above-described capping operation, all heads of the recording heads 1C, 1M, 1Y, and 1Bk are ejected from the recording head ejection surface in the capping state to the ink absorbers 3C, 3M, 3Y, and 3Bk that are held with a fixed gap. Is given an arbitrary number of ink discharge pulses to the discharge energy generating means. In this manner, it is possible to prevent non-ejection due to ink sticking to all the ejection openings, and prevent ejection failure and image disturbance due to ink whose viscosity has changed. Normally, the idle discharge operation is set to be performed when the copy is ON.

Next, the ink discharging operation will be described. FIGS. 11 (1) to 11 (4) show a recovery / capture unit when performing an ink pressurizing and circulating operation in an ink supply system as an ink discharging operation.
306 is a schematic diagram showing the operation in 306. FIG. The operation in the recovery / capture unit 306 includes (1) normal capping,
(2) ink pressure circulation, (3) absorber squeezing and wiping,
(4) Absorber contact, there are (1) to (4) cycles. (1) to (4) in FIG. 11 correspond to these.

First, (1) Capping refers to the above-described capping, which is a normal standby state or a pause state. In this state, when the mode of the ink pressurization and circulation is selected by a command from the user or the host computer, for example, the state shown in FIG. 11 (2) is obtained. That is, each of the ink absorbers 3C, 3M, 3Y, 3Bk held with a certain gap is replaced with the recording heads 1C, 1M, 1B.
Contact each of Y and 1Bk. In this state, the corresponding ink absorber and the head ejection surfaces are joined to each other.
In this state, an ink supply pump (not shown) is driven into each of the recording heads 3C, 3M, 3Y, and 3Bk to forcibly increase the ink supply pressure. As a result, the ink circulates through the ink supply system through the head to remove bubbles inside,
The pressurized ink is discharged from the discharge port. As a result, dust and the like attached to the discharge surface are removed together with the discharged ink, and the vicinity of the discharge port is cleaned. As described above, the ink discharged from the head discharge port is absorbed by the ink absorber 3 (3C, 3M, 3Y, 3Bk) abutting on the discharge surface without leaking to other portions, and further absorbed by the absorber. The ink exceeding the maximum saturation amount travels through the absorber by the own weight of the ink, falls into the recovery container 2, passes through the discharge ink port 13, and is guided into the discharge ink tank (not shown) by the discharge ink hose 12. . At this time, the pressurizing circulation time, that is, the pressurizing time of the supply pump is usually preferably about 0.5 seconds to several seconds from the efficiency of removing the fixed ink and removing bubbles.

 Next, (3) absorber squeezing and wiping will be described.

(2) When the pressure circulation is completed, the ink absorber 3 that has been in contact with the head discharge surface is separated from the discharge surface again.
Then, in this state, the ink substantially saturated with the ink absorber 3 is squeezed out by the squeezing member 5.
The squeezed ink is absorbed by the absorber guide 7,
After passing through the partition plate 8 and falling into the recovery container 2, the ink discharge port 13
Through the discharge ink hose 12 and into the discharge ink tank. At the same time, that is, the ink absorber 3 is detached from the head ejection surface, and the absorber is squeezed, and at the same time, the ejection surface wiping blade 88 is driven, and the ejection ink, dust, and deposits remaining on the head ejection surface are driven. Etc. can be wiped out. The wiped ink or the like falls onto the ink absorber 3, but at the same time, since the above-described squeezing operation is performed, these falling objects also fall into the recovery container 2 together with the squeezed ink, Further, it is led to a waste ink tank. That is, at the same time as the ink absorber 3 is separated from the ejection surface, the residue adhered to the ink ejection surface is removed by the blade 88
At the same time, and squeezes out the attached matter together with the surplus ink in the ink absorber.

This is the above-mentioned (3) operation of squeezing and wiping the absorber. The ink absorbing member 3 is squeezed by the squeezing member 5 so that its absorbing ability is restored, and the ink absorbing member 3 is prepared for the next ink absorption. The ink absorber 3 is preferably made of, for example, a highly water-absorbing sponge such as PVF resin, and is desirably one that can withstand repeated use. In this example, for example, Kanebo Berita (trade name) was used. The absorber from which the absorbed ink has been squeezed out then comes into contact with the head ejection surface again. This is (4) absorber contact. In the stage (2), the ink that could not be completely absorbed from the head ejection surface because the absorber was almost saturated was squeezed in this stage to restore the absorbing ability and to clean the ink. It is completely cleaned by the contact of the absorber.

After performing these series of operations (1) to (4),
The capping (1) is again performed, that is, the standby state is established, and the cleaned head is kept well. Normally, these pressurizing and circulating operations are performed when the main body is turned on or after a long standby time.

As described above, by performing the recovery operation of the cap, the idle discharge, and the ink pressurization circulation, the disturbance of the recorded image due to the ink discharge, that is, the discharge failure at the time of image formation is prevented (recovered).

Next, the printing operation will be described. Fig. 12 (a)-
(F) is each state diagram when starting a printing operation from the standby state of the recovery system described above. First, (a) the cap is the above-mentioned cap state, which is a normal standby state or a pause state. In this state, when the print mode (copy ON) is selected, first, the above-described idle discharge operation is performed. Subsequently, a state shown in FIG. 12 (b) is shown, ie, a state in which the recording head 305 is retracted upward. In this state, the recovery container 2 as the recovery / cap unit 306 retreats in the upper right direction in FIG. This state is (c) unit open, and after this state, (d) head down is performed. As a result, the head is placed in a printable state (position) as shown in FIG.
Further, the recovery system container 2 is placed at the evacuation position. In this state,
The recording paper is fed from the head discharge surface with a constant gap from the right in the figure, while the heads 1C, 1M, 1Y, 1Bk
An image signal is input, ink is ejected, and printing is performed on recording paper.

When the printing on the recording paper has been completed, that is, the head where the ink ejection has been completed, the head-up operation is performed again as shown in FIG. 12 (e), and then the recovery system as shown in FIG. 12 (f). The container 2 is moved to the position on the head side, and returns to the state shown in FIG. 12A, that is, the cap state, and enters the standby state in preparation for the next printing. (A) to (f) above
, A normal copying operation is performed. In addition, the above-described ink circulation is performed at a predetermined timing during the (a) capping operation in the present operation, that is, at a predetermined timing during the standby operation, for example, when the power is turned on, or every time a predetermined time elapses. It is possible to prevent the deterioration and obtain a good image.

FIG. 13 is a registration roller (415, 416 in FIG. 1) schematically showing a (belt conveying portion) of the recording member (recording paper) conveying means.
The recording paper that has exited the conveyor belt 101 along the guide plates 417 and 418
Reach The transfer belt 101 has an insulating layer (preferably at least 10 ¹² Ω · cm in volume resistance) on the side where the recording paper is placed, and a conductive layer (preferably not more than 10 ⁸ Ω · cm) on the opposite side. It has a layer structure. The transport belt 101 includes a driving roller 102, a driven roller 103, a tension roller 104,
It is wound around 105 and mounted with a tension of, for example, 2 to 5 kg. The transport belt 101 is moved in the direction of the arrow AA in the figure by a motor (not shown) that applies a driving force to the driving roller 102 connected to the driving roller 102.

The recording paper is placed on the transport belt 101 immediately before the conductive roller 107. At this time, the surface of the conveyor belt 101 is given a potential of several hundreds to several thousand volts by the charger 106. The recording paper placed on the conveyor belt 101 is contacted with a grounded conductive roller 107.
Is reached, the recording paper is kept in close contact with the transport belt 101 by the electrostatic attraction force, so that the recording paper comes into close contact with the transport belt 101 and moves with the transport belt 101.

In this state, the recording paper reaches a recording area facing the recording head 305. The recording head unit 305 has a head block 6 and recording heads 1C, 1M, 1Y, and 1Bk.
Platen 115 is a conveyor belt on the side facing C, 1M, 1Y, 1Bk
It is provided through 101. The platen 115 has a pin
The platen 115 is pressed and supported on the recording head 305 side by a spring 117 and a guide pin 118. In the recording area, the interval between the recording heads 1C, 1M, 1Y, and 1Bk and the recording surface of the recording paper is maintained at an accuracy of about 100 μm with respect to a desired set value in order to obtain high-quality image recording. Is desired. Therefore, the flatness of the platen 115 on the surface in contact with the transport belt 101 is kept within about several tens μm so that the transport belt 101 forms a substantially flat surface in the recording area. In addition, recording heads 1C, 1M, 1Y, 1
Bk is positioned and fixed to the head block 6 such that the flatness formed by the discharge port surfaces of all the heads is within several tens of μm. A pin 116 for positioning is attached to the platen 115. In this state, if the platen 115 is pushed up in the direction of the head block 6 by the repulsive force of the spring 117 using the guide pin 118 as a guide, the upper part of the pin 116 and the head block 6 come into contact,
A clearance 1 for recording paper passage is formed. When the recording paper is conveyed in such a configuration, since the recording paper is in close contact with the conveyance belt 101 by an electrostatic attraction force, the distance accuracy between the recording surface of the recording paper in the recording area and the ejection port surface of each recording head is improved. Is kept within a desired range with respect to the set value.

When the recording paper passes through this recording area, the recording heads 1C and 1C
M, 1Y, and 1Bk sequentially perform image recording in accordance with recording information. At this time, if the speed fluctuation of the transport belt 101 is large, the recording position due to each head is shifted, and a color shift or color unevenness occurs in a color image. In order to prevent this, the thickness accuracy of the conveyor belt 101, the outer diameter deflection of the drive roller 102, the rotation accuracy of the drive motor, etc. are within desired ranges,
The configuration is such that the speed fluctuation of 101 is sufficiently small so that there is substantially no problem.

The recording paper recorded in the recording area reaches the drive roller 102 while being in close contact with the transport belt 101, where the drive roller 102
Is separated from the conveyor belt 101 by the curvature of the conveyor belt formed by the above, and sent to the fixing unit.

Thereafter, the surface of the transport belt 101 is cleaned by a cleaner 120 having an ink absorber 119. Ink absorber 119
Is formed of a continuous porous member such as a polyvinyl formal resin, and the absorbed ink flows out and is collected outside through the opening 120.

Note that, in the present embodiment, an example has been described in which the transport belt 101 has a two-layer configuration including an insulating layer and a conductive layer, but the transport belt 101 may be a single-layer insulating layer having a desired volume resistance. Alternatively, the insulating layer and the conductive layer may have a multilayer structure.

 Hereinafter, the configuration of the fixing unit will be described in detail.

In the ink jet recording method, ink is attached to a recording member, and the ink penetrates into the recording member and is fixed. Alternatively, the ink is fixed on the recording member through a process of evaporating the solvent of the ink.

However, the time from when the ink adheres to when the ink is fixed, that is, the fixing speed, not only greatly depends on the configuration and physical properties of the recording member, but also greatly changes depending on the state of the external atmosphere. Further, the speed of fixing naturally cannot be made shorter than a certain time due to physical characteristics.

In many conventional serial scan recording apparatuses, the fixing property can be dealt with with a somewhat simple configuration due to the recording speed. However, in recent years, when high-speed recording and color recording are performed by a line printer or the like, there is a case where the ink is conveyed and discharged to the outside of the apparatus without the ink being sufficiently fixed on the recording member. Therefore, a fixing unit for shortening the fixing speed and increasing the efficiency is required, and the configuration is shown in FIG.

In the figure, a heating element 200 corresponds to a surface of the recording member 210 to which ink is not attached (non-recording surface), and another heating element 201 corresponds to a surface of the recording member 210 to which ink is attached (recording surface). Heat. The heating element may be a halogen lamp, a sheathed heater, a thermistor, or the like.In this configuration, several thermistors having a temperature control function are used for the heating element 200, which is made of aluminum or the like and has excellent heat transfer properties. The non-recording surface of the recording member 210 is contact-heated. On the other hand, a halogen heater is used as the heating element 201, and warm air is sent onto the recording member 210 by the fan 203 provided above the heating element 201 to heat the recording surface of the recording member 210 in a non-contact manner. Even when the recording member 210 rises from the carriage 202 due to the adhesion of ink and causes a curl peculiar to the ink jet, the fan 203 sends out the warm air downward, so that the recording member 210 is reliably sent along the high-temperature carriage 202. . Therefore, since both sides of the recording member 210 are sufficiently dried, the penetration of the ink is promoted, and the fixing speed is greatly reduced due to a synergistic effect.

The fixing temperature is set by a thermostat 204 that controls the temperature of the thermistor and the heater, and can be appropriately controlled according to the paper quality of the recording material. Also, in order to prevent the fixing heat from affecting the head and the ink in the supply system, a partition plate 205 having a heat insulating material such as glass fiber adhered to the surface is provided.
The heater holder 206 contains polyphenylene oxide (PP
O) and other resins with excellent heat resistance are used to prevent excessive transmission of fixing heat. Further, an exhaust fan 207 is provided, and excess fixing heat is discharged outside the apparatus.

In addition, a heater cover 208 such as a wire mesh is installed in consideration of the safety of the recording member in the event of a jam.

With the above-described configuration, the recording member 210 is heated directly on the non-recording surface and heated by hot air on the recording surface by double fixing. In particular, the recording member 210 is formed by an ink jet recording method, in particular, for example, a color ink jet recording in which ink droplets are overprinted. It is possible to prevent the fixing property from deteriorating due to curling of the recording member due to waving.

Next, the sequence of image recording after the power of the apparatus is turned on will be described with reference to FIGS. 1 to 2, FIGS. 9 to 15, and FIGS. 19 to 27. 20 to 27 show a subroutine of the flowchart of FIG.

First, when the power of the ink jet recording apparatus is turned on,
As shown in the state diagram in FIG. 11, (1) Capping,
After a series of operations (2) ink pressure circulation, (3) absorber squeezing, and (4) absorber contact (subroutine in FIG. 20: ink pressure circulation operation), the operation returns to (1) the capping state again. As a result of this series of operations (Step 1 in FIG. 9), there is a long stoppage of the apparatus before the power is turned on, and the ink sticks due to thickening (drying, ie, the viscosity increases due to evaporation of the solvent) and bubbles are formed. Non-discharge of ink due to occurrence can be prevented. A series of operations following (1) capping, (2) ink pressure circulation, (3) absorber squeezing, (4) absorber contact, and (1) capping is hereinafter referred to as ink pressure circulation operation. The ink pressurizing and circulating operation is not always performed immediately after the power is turned on. For example, after use or power supply in a high-temperature, high-humidity environment where ink thickening or the like is likely to occur, there is a long-time non-use or standing state, and the above-mentioned problems such as sticking and generation of bubbles are considered. The problem is solved by causing the ink pressurizing and circulating operation to be performed at regular intervals (within the allowable time during which the problem does not occur, hereinafter referred to as cycle time) by a timer means or the like. Further, a humidity sensor (not shown) is provided in the vicinity of the recording head unit 305, and the signal indicates how many hours the ink pressurizing and circulating operation is performed.
And a change control for how many seconds the ink pressurizing time is performed. That is, when used in a low humidity state, the cycle time is shortened or the ink pressurizing time is lengthened. It has also been confirmed that changing both of them at the same time is more effective.

Here, unless a recording start signal is input, the ninth
The capping state shown in the figure is maintained. When a recording start signal is input, as described in FIG. 10, a predetermined number of ejection pulses are applied to all nozzles of all recording heads to perform a non-ejection operation for causing ink to be ejected, thereby preventing non-ejection immediately before recording. Do. This is shown in step 19 in FIG. The number of pulses of this idle discharge is also controlled by the signal of the humidity sensor in the same manner as in the ink pressurizing and circulating operation. That is, in the low humidity state, the number of idle ejection pulses is increased. The difference in the effect of the ink pressurizing and circulating operation and the non-ejection operation on the non-ejection prevention is greater in the former, and therefore, the time during which the non-ejection cannot be prevented due to thickening or sticking of the ink even in the idling operation is increased. This is a determining factor of the cycle time for performing the pressure circulation operation. Therefore, when not in use, the capping means shuts off the ejection surface of the recording head from the outside air, prevents the ink from drying and fixing to some extent, and allows all the nozzles of the head to be ejected only by idle ejection. Is configured. When the idle discharge operation shown in the subroutine flow chart shown in FIG. 21 is completed, as shown in FIGS. 12 (a) to 12 (d), after the head moves upward and retreats, the idle discharge operation ends. Perform a unit open operation to retreat in the direction. This operation is a subroutine: unit open operation.
As shown in FIG. Subsequently, the head unit 305 moves the head discharge surface vertically downward around the rotation center N, that is, the transport head.
It swings so as to face the surface of 101 (a head-down operation is performed, which is shown in step 3 in FIG. 19). The head portion 305 is in contact with an abutment surface (not shown) provided on the head block 6 and a pin 116 provided on the platen 115 and a spring 117 pushing up the platen 115.
Stop at a position slightly depressed against The stop position is detected by the print position detection sensor and stopped. Further, a worm gear (not shown) is used as a part of a transmission system of a driving source for swinging the head portion 305, and the head portion 305 is pushed up by the reaction force of the spring 117 due to the characteristic of the advance angle. Without stopping. The head is now ready for printing. Next, as shown in the subroutine flowchart of FIG. 23, the recording member (paper) stored in the cassette 411 is fed by the pick-up roller 412 and stopped via the conveying rollers 413, 414 and the guide section 419. Register roller pair 41
It has been sent to 5,416 nips. Here, after the leading end of the sheet comes into contact with the nip portion of the pair of register rollers 415, 416, the sheet is further fed out by the transport rollers 413, 414 for a further short period of time. This operation is a registration means usually performed by an electrophotographic copying machine or the like, and the registration of the leading end and the correction of the skew of the sheet are performed by the loop force.

Next, the pair of register rollers 415 and 416 starts rotating and guide 4
The paper is sent out onto the conveyor belt 101 via 17,418. Based on the signal for starting rotation of the pair of register rollers 415,416, a signal for starting scanning of the document and a printing start signal for each of the heads 1C, 1M, 1Y, 1Bk are issued. The recording paper fed onto the conveyor belt 101 is brought into close contact with the surface of the conveyor belt 101 sequentially from the leading end by electrostatic attraction, and the recording heads 1C, 1M, 1Y, 1B
When passing just below k, printing is performed by the above-described means while the head ejection surface and the recording paper surface hold an appropriate gap. This is shown as a subroutine flowchart in FIG. Thereafter, the sheet is conveyed to the fixing / discharge unit 307. When the sheet is transferred from the conveyor belt 101 to the guide 213, the diameter of the drive roller 102 is set to a relatively small value, and the sheet is naturally moved by the strength of the paper. The separation is performed by means of so-called curvature separation. Where the drive roller 10
The diameter of 2 is such that the moving distance of the surface of the belt 101 frictionally driven by one rotation thereof is equal to the distance between the respective discharge ports of the head 1C, which is the first head, and the head 1Bk, which is the fourth head. It is set as follows. This is a drive roller
This takes into account the fact that an eccentric component at the diameter of 102 causes a misregistration on the image. Ideally, the surface of the belt 101 is driven by one rotation of the drive roller by the distance between the discharge ports of the adjacent heads. However, in consideration of mechanical strength, the minimum value of the diameter of the drive roller 102 is considered. There is a limit, and considering this, it is relatively large. This requires three times the distance between the four heads, which leads to an increase in the size of the device. Therefore, the distance between the first head and the fourth head, which is the farthest head distance and includes many other misalignment factors, is considered. However, it may be between the first head and the third head or, of course, between adjacent heads, and is not limited to the above. However, some consideration is required for the diameter of the driving roller and the distance between the heads as described above.

Next, the fixing process of the sheet sent to the fixing / discharge unit 307 is described. There are three modes. This will be described with reference to the flowchart of FIG. 25 subroutine.
As described above, when coated paper is used as recording paper, there is no need for fixing, but when non-coated paper called plain paper is used in a so-called electrophotographic copying machine or the like, a fixing unit is required. That is, in the first mode, when recording and printing on plain paper in the plain paper mode, the heating element A200 and the heating element B201 are simultaneously turned on by the recording start signal. Power is supplied to the fan 203 only when the register roller 41 is turned on.
This is performed at the timing when the sheet is delivered from the conveyor belt 101 to the guide 213 by the timer means from the rotation start signal of 5,416.

This is because it takes about 1 to 2 seconds for the halogen heater of the heating element B201 to rise to the set temperature. When the fan 203 is rotated from the beginning and the wind is applied to the halogen heater, the rise time is extended, and the paper is fixed to the fixing unit. This is because when the sheet is conveyed to 307, the temperature does not reach the set temperature, and the fixing effect is reduced. Next, when using the coated paper of the second mode in FIG. 26 as the recording paper, a mode key for selecting the coated paper is provided on the operation unit (not shown), and after selecting this key, the recording start is started. Image recording is performed by a signal, but at this time, power is not turned on for both the heating element A200 and the heating element B201. As described above, in the coated paper, the ink is rapidly absorbed into the inside, so that the fixing auxiliary means as described above is unnecessary. However, in consideration of an emergency such as an operation error, the first mode, that is, the plain paper mode is the priority mode, and unless the operator selects the second mode, the coated paper mode, as described above, the fixing is performed. The auxiliary means operates. Therefore, even when an image corresponding to coated paper is erroneously printed on plain paper, it is possible to prevent a problem that the ink is offset to the discharge roller 211 described later and disturbs other recording paper.

In addition, the apparatus has a third mode in FIG. 26, which is an overhead projector film (OH
P) Paper (film) mode. O used for this device
HP paper is coated with the same characteristics as coated paper, but nevertheless, when printing is repeated in the same place in a short time, there are phenomena such as ink bleeding and bleeding. Further, the time required for the ink to be completely absorbed in the coat layer is long, and if something comes into contact with the image surface within a short time after printing, the image is disturbed or an offset occurs. In order to prevent this problem, it is necessary to extend the time for superimposing the images next time to absorb the ink. Further, in order to prevent offset or the like, the time from printing to contact with the image surface is increased. Alternatively, it is conceivable to intervene the fixing means during that time. In this apparatus, all the transport speeds related to the paper feed, such as the paper feed speed, the heald transport speed, and the discharge speed, are reduced to the speed at which the above-mentioned problem is solved while maintaining the ratio employed in the first mode and the second mode. (Low-speed mode) In addition, the driving frequency of the head is also changed at the same time so that an appropriate image is printed. That is, the operation unit (not shown) is provided with an OHP mode selection key. When this mode is selected and a recording start signal is input,
The transport speed from 303 to the registration rollers 415 and 416, the transport speed of the belt of the belt transport unit 304, and the discharge rollers 211 and 212
In addition to the low speed mode conveyance at all the discharge speeds, the heating element A200, the heating element B201, and the fan 203 are turned on at the same timing as in the first mode to assist in fixing.

The plain paper, coated paper, and OHP paper described above are finally conveyed and ejected by the discharge rollers 211 and 212, and are ejected from the tray 420.
However, the transport speeds of the respective paper transport units are different from each other, and the reason and contents will be described below.

In the configuration of the present apparatus, the process speed determined by the recording speed of the apparatus is achieved by the transport speed of the transport belt 101. That is, the transport speed of the transport belt 101 is set to be the same as the process speed. Therefore, assuming that printing from the head is performed at a correspondingly accurate speed, if the transport speed of the transport belt 101 is lower than the set speed, the image shrinks in the transport direction from the regular one, and conversely, if it is faster, the image is stretched and printed. Will be formed. On the other hand, the transport speed of the register rollers 415, 416 is set slightly lower than the transport speed of the transport belt 101. This is to prevent the conveying force of the register rollers 415 and 416 from affecting the conveying force of the belt 101. For example, if the conveying speed of the register rollers 415, 416 is set lower than the speed of the belt 101, the paper is conveyed by the register rollers 415, 416, delivered to the belt 101, and electrostatically attracted and held on the surface. At the position where printing is started at the first head, the sheet is still only partially sucked from the leading end. At this time, the conveying force of the register rollers 415 and 416 overcomes the conveying force of the belt 101 and the register rollers 415 and 416
Is controlled by the transport speed of the belt 101, the transport of the belt 101 proceeds, and the suction width of the paper increases, and the transport force is reduced by the rollers 415, 41.
An abnormal image is formed until the conveyance force of 6 is overcome. For this reason, in this apparatus, the transport speed of the roller pair 415, 416 is set higher than the transport speed of the belt 101, and the distortion of the sheet caused by the difference in speed is eliminated by forming a loop between the guides 417, 418. Therefore, in this configuration, the conveying force of the roller pair 415, 416 does not affect the conveying force of the belt 101. However, if the speed difference is set large, the loop becomes large, and the suction operation becomes unstable due to fluttering or the like. Therefore, the speed difference is preferably zero or small enough that the speed difference does not reverse, and the ratio is experimentally 0 to 1.
It has been found that about 5% is good. Next, the transport speed of the paper discharge unit will be described. In the case of a normal configuration, the belt 101 and the discharge rollers 211 and 212 do not affect the conveyance speed of the belt unlike the relationship between the pair of registration rollers and the conveyance belt.
It is sufficient to form a loop between them.However, in the present apparatus, a sheet which also serves as a guide such as a heating element A200 as a fixing means is provided along the surface of the transfer table 202 on the downstream side of the belt transfer apparatus 304 so as to form a sheet. Since the paper is heated from the back side, if a loop is formed here, the paper will not be able to follow the surface of the conveyance base 202, and the fixing effect will be significantly reduced. Therefore, in the configuration of this apparatus, the transport speed of the paper discharge rollers 211 and 212 is set to be higher than the transport speed of the belt 101, so that a loop is not formed on the paper. At this time,
The heating element is located at a position slightly higher than a plane obtained by connecting the suction surface of the belt 101 and the nip positions of the discharge rollers 211 and 212.
The sheet conveying surface of the conveying table 202 of the A200 is set, and when the leading end of the sheet is nipped between the sheet discharging rollers 211 and 212, the sheet is further conveyed along the surface of the conveying table 202. Here, the conveyance force of the discharge rollers 211 and 212 is adjusted so that the conveyance force of the discharge rollers 211 and 212 is not greater than the adhesion force of the belt 101 to the sheet. It has been optimized. In order to prevent the offset during fixing, the surface of the paper discharge roller 211 which comes into contact with the image surface of the paper is coated with nylon fiber to reduce the frictional force, and the paper discharge roller 212 is made of resin (for example, polyacetal). ) Etc. composed belt
It achieves a lower conveying force than the 101 conveying force.

With the above transport speed configuration, good recording can be performed without disturbing the image at the time of printing.

Here, as described above in further detail of the transportability of the belt transport unit 304, as described above, when the transport speed of the transport unit 304 changes, not only affects the expansion and contraction of the image,
In the case where an image is formed by superimposing inks such as a color image even by a minute fluctuation in speed, this causes image defects such as misregistration of registration and unevenness of color. Therefore, the belt 101 must be conveyed (the waffle for conveyance) with high precision while sufficiently considering the driving source of the driving roller 102, the outer diameter accuracy of the driving roller 102, the thickness accuracy of the belt 101, and the like. In addition to these factors, consideration must also be given to disturbances in the transport unit 304 that deteriorate the wow flutter.
As described above, when the sheet sent out from the belt 101 is delivered onto the belt 101, the pair of register rollers 415, 41
Since the transfer speed of 6 is faster than the transfer speed of belt 101, the belt
101 has a structure in which it is pushed by paper, and this external force deteriorates the wow flutter of the belt 101. If printing is being performed on the paper preceding this point, color unevenness, registration deviation, etc. will occur in the image as described above. In order to prevent this problem, in the present apparatus, when performing continuous image recording, the timing at which the paper is transferred onto the belt 101 is performed after the trailing edge of the previous paper has passed the fourth head printing unit. Thus, the sequence is such that the next sheet is not delivered to the belt 101 during printing. This is performed by the timer means from the ON signal of the pair of registration rollers 415 and 416 as described above by calculating the time required for the trailing edge of the sheet to pass through the fourth head print section in consideration of the length of the sheet being transported in the feed direction. ing.

The above is the operation from the start of recording to the end of printing and discharge of paper. When the set number of copies has been completed, as described in FIGS. 12 (e) and 12 (f), the head-up and then the unit-close are performed. The operation is performed, and finally a capping state is set as shown in FIG. 3, and a series of recording operations is completed. Here, when recording is performed in the first mode and the third mode, the heating element A200, the heating element B201, and the fan 20 are used.
The energization to 3 is interrupted at the timing when the trailing end of the sheet passes through the pair of discharge rollers 211 and 212. This timing is arm 21
This is performed by a sensor 213 that detects passage of the leading edge of the paper in conjunction with 4. This is shown in FIG. 25 subroutine paper discharge operation.

Step 5 shows a state in which the recording operation is repeated until the predetermined number of sheets is completed.

Next, the above-described non-ejection prevention sequence (step 6 in FIG. 19) will be described with reference to FIGS. 15 and 27 in which the head control sequence is flow charted.

As described above, when the apparatus is turned on, the ink circulation recovery operation is performed in consideration of a case where the apparatus has been left in a non-printing state for a long time. Thereafter, the apparatus stands by until a recording start signal is input in the capping state. During that time, if the fixing timer means operates, the circulation recovery operation is performed again. The sticking timer means prevents non-discharge due to an increase in ink viscosity when the non-printing state continues for a long time even after the power is turned on, and the timer setting time varies depending on the characteristics of the ink and its use environment. But on the order of hours.

Next, when a recording start signal is input, the idle discharge operation is performed, and then the head is downed to perform print recording. If the first timer is activated during recording, the head is closed up to perform idle discharge operation, and then the head is down and recording is continued. In order to prevent the nozzles not used for printing from becoming non-ejecting in consideration of the case where all the nozzles are not ejected during printing, the above-mentioned one-shot timer is performed by a timer means after a predetermined time from the previous idle ejection. Is what you do. This is to recover a slight non-discharge by the idle discharge means, which is of the order of a few minutes in a relatively short time. When the recording of the set number of images is completed in this way, the head-down state is maintained for a certain period of time set by the firing timer, and the next recording start input signal is waited. If a recording start signal is not input within the set time of the first timer, the head is closed, the unit is closed, and a capping state is set. If a recording start signal is input within the set time, the recording is started as it is, and the image recording sequence described above (this is shown in the flowchart of FIG. 27) is performed. Here, the first remaining timer can be replaced with the first remaining timer. The first firing timer is a time obtained by subtracting the time from the previous idle discharge to the end of image recording from the first timer time, but since the head is in a head-down state and is not in a capping state, it is a standby time. In consideration of the fact that the ink dries easily, the time is set slightly shorter than the calculated deduction time.

〔The invention's effect〕

As described above, the present invention is an inkjet recording apparatus having an inkjet-specific recovery mechanism for an inkjet head provided with a plurality of ejection ports,
A housing that integrally holds the ink jet head, the head holding means, the head recovery means, the head moving means, and the recovery moving means is an ink jet recording apparatus detachable from the apparatus main body. Such an invention of the present application has an effect that the size of the device can be reduced and the unit configuration can be made maintenance-free.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view of an ink jet recording apparatus according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are sectional views of a main part of a head recovery system in FIG. FIG. 3, FIG. 3 is an explanatory view of a positioning and fixing portion of the recording head, FIG. 4 is an explanatory view of a drive section of the recording head, and FIGS. FIGS. 6 (a) and 6 (b) are explanatory views of a recovery cap driving portion, respectively, and FIGS. 7 (a) and (b) are detailed views of a recovery ink absorber aperture drive portion, respectively, and FIG. 8 (a). 9 (b) is an explanatory view of a recording head ejection surface wiping unit, FIG. 9 is a sectional view of the recording head in a capped state in FIG. 2, FIG. 10 is a sectional view showing an idle ejection operation of the head in FIG. FIG. 11 is a state diagram showing the ink pressurizing circulation operation, and FIG. 12 is a standby state of the recovery system shown in FIG. FIG. 13 is a detailed sectional view of the belt conveying section in FIG. 1, FIG. 14 is a detailed sectional view of the fixing and discharging section in FIG. 1, and FIG. 15 is a head section. FIG. 16 is a flow chart showing one sequence of control, FIG. 16 is an explanatory diagram schematically showing the configuration of a long recording head and ink supply means, FIG. 17 is a schematic configuration diagram of a conventional ink jet recording head, FIG. FIG. 19 is a block diagram of a conventional ink jet recording apparatus in which recording heads are arranged. FIG. 19 is a flow chart of the whole embodiment of the present invention, and FIGS. 20 to 27 are flow charts of a subroutine of FIG. , Ink pressurizing and circulating operation, idle discharge operation, unit open operation, paper feeding operation, recording operation, paper discharging operation, heating element control, and flow chart of a fixing timer.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tatsuo Mitomi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Masaharu Nemura 3-30-2 Shimomaruko, Ota-ku, Tokyo (56) References JP-A-63-208787 (JP, A) JP-A-62-159565 (JP, A) JP 6-61981 (JP, B2) JP 6-65497 (JP , B2)

Claims (5)

(57) [Claims] An inkjet head provided with a plurality of ejection ports for ejecting ink to perform recording on a recording material; a head holding means for holding the inkjet head; A head recovery unit for performing recovery of the ejection port, a recording position where the ejection port performs recording facing the recording material, and a recovery position where the ejection port performs recovery facing the head recovery unit. A head moving unit for moving the inkjet head, a head retreat unit facing the ejection port, and a recovery retreat position in which the head recovery unit retreats away from the ink jet head. Recovery moving means for moving the recovery means, the inkjet head, the head holding means, the head recovery means, and the head It includes a housing for holding integrally the the motion means the restoration moving means, the ink jet recording apparatus wherein the housing is detachable from the apparatus main body. 2. The apparatus according to claim 1, wherein said head recovery means includes capping means for capping said discharge port, and said capping means includes an absorber capable of contacting said discharge port. 2. The ink jet recording apparatus according to item 1, wherein 3. The head moving means rotates the head holding means about a rotation axis, so that the recording position, the recovery position, and the head holding means are in the recovery position with respect to the recording position. 2. The ink jet recording apparatus according to claim 1, wherein the ink jet head is moved so as to be able to stop at a head retreat position further rotated from the ink jet head. 4. The ink-jet recording apparatus according to claim 1, wherein said ink-jet head is provided with a plurality of said discharge ports provided with a substantially same width as a recording material and made longer. 5. The ink-jet head according to claim 1, wherein said ink-jet head has a heating element for generating heat energy used for discharging ink from said discharge port. Inkjet recording device.