JPH07125357A - Ink-jet recording device - Google Patents

Abstract

PURPOSE:To prevent an image from being detriorated such as color drift from being caused, by keeping a space and parallelism between a discharge port face and platen face of a recording head properly always and preventing accuracy in inking from being deteriorated during recording even in the case where unevenness is caused in the platen surface due to dispersion in accuracy of parts or assembly. CONSTITUTION:Freely turnable carriage rollers 26, 27 pressing recording paper 1 against a platen face 14 through a paper press member 12 during recording are provided in a carriage 19 and the carriage rollers 26, 27 are energized and held to the carriage 19 by an elastic member 30.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording apparatus for recording by ejecting ink from a recording means onto a recording material.

[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 multifunction machine or a workstation including a computer, a word processor, etc., is a sheet or a plastic thin plate based on image information. An image (including characters and symbols) is recorded on a recording material (recording medium) such as (OHP). The recording device can be classified into an ink jet type, a wire dot type, a heat sensitive type, a thermal transfer type, a laser beam type and the like depending on the recording system of the recording means used.

In a serial type recording apparatus which employs a recording system in which a main scanning is performed in a direction intersecting a conveying direction (sub-scanning direction) of a recording material, the recording material is set at a predetermined recording position and then the recording material is set. An image (including characters, symbols, etc.) is recorded by a recording unit (recording head) mounted on a carriage that moves (main scanning) along, and after one line of recording is completed, a predetermined amount of paper is fed (sub-scan). An image is recorded in a desired range of the recording material by repeating the operation of performing (scanning) and then recording (main scanning) the image of the next row. On the other hand, in a line type recording apparatus that records a recording material only in the sub-scanning direction in which the recording material is fed in the transport direction, the recording material is set at a predetermined recording position, and one line of recording is continuously performed at one time. A predetermined amount of paper feed (pitch feed) is performed, and an image is recorded on the entire recording material.

Among them, the ink jet type (ink jet recording apparatus) is a means for recording by ejecting ink from a recording means (recording head) onto a recording material, and it is easy to make the recording means compact and high definition. Images can be recorded at high speed, plain paper can be recorded without requiring special processing, running costs are low, and the non-impact method reduces noise and uses multicolor inks. Therefore, it has an advantage that it is easy to record a color image.

In particular, an ink jet type recording means (recording head) for ejecting ink by utilizing heat energy,
Through the semiconductor manufacturing process such as etching, vapor deposition, and sputtering, the electrothermal converter formed on the substrate, the electrode,
By forming the liquid passage wall, the top plate, and the like, it is possible to easily manufacture a liquid discharge device having a high-density liquid passage arrangement (ejection port arrangement), and to further reduce the size. Further, by utilizing the advantages of IC technology and micro processing technology, it is easy to make the recording means long and planar (two-dimensional), and it is also easy to make the recording means full-multi and high-density mounting. is there.

In the above-mentioned serial type ink jet recording apparatus, a recording material is intermittently fed by a conveying roller mechanism which is a conveying means, and recording is performed in a direction intersecting the paper feeding direction while the paper feeding is stopped. The carriage carrying the head is moved (main scanning), and the recording head is driven according to an image signal during the carriage movement, whereby ink is ejected onto the recording material to perform recording. There is. In that case, in the recording portion of the recording material facing the recording head, the back surface is guided and supported by a platen.

Further, in the ink jet recording apparatus, it is required to accurately regulate the distance between the recording head and the recording material. As a mechanism for this, a plurality of carriage rollers are provided around the recording head of the carriage. , A paper pressing member for closely contacting the recording material with the platen surface is provided in the vicinity of the recording portion, and the recording material on the carriage is recorded by the carriage roller pressing the recording material via the paper pressing member during recording. A mechanism for maintaining a constant gap between the head and the recording material on the platen is adopted.

[0008]

However, in the conventional ink jet recording apparatus of this type, a part of the platen surface is uneven due to variations in platen mounting accuracy and platen plane accuracy. When the carriage roller rolls over the uneven shape through the paper pressing member, the carriage itself tilts with respect to the platen surface, and the ejection port surface of the recording head on the carriage is also similar to the platen surface. And as a result,
When color recording is performed using a plurality of recording heads, a deviation occurs in the landing direction of ink ejected from each recording head, color superimposition does not work well, and image quality deteriorates. There were challenges.

The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide even if unevenness is generated on the platen surface due to variations in parts accuracy and assembly accuracy.
During recording, it is possible to always maintain an appropriate distance and parallelism between the ejection port surface of the recording unit and the platen surface that is disposed opposite to the ejection port surface, prevent deterioration of ink landing accuracy, and prevent image deterioration such as color misregistration. It is an object of the present invention to provide an inkjet recording device capable of preventing the above.

[0010]

SUMMARY OF THE INVENTION The present invention relates to an ink jet recording apparatus for recording ink on a recording material on a platen by ejecting ink from a recording means mounted on a carriage, the carriage interposing a paper pressing member during recording. The above object is achieved by having a carriage roller for pressing the recording material on the platen, and the carriage roller is biased and held by the carriage by an elastic member.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of an inkjet recording apparatus to which the present invention is applied. In FIG.
Reference numeral 1 denotes a recording material (recording medium) such as a sheet or a plastic thin plate stacked in a paper cassette (not shown), and 2 denotes a bottom plate 17 at a predetermined position between the paper cassette (not shown) and the transport roller 6.
The lower paper guide 3 fixed to the upper paper guide 3 fixed to the bottom plate 17 with a proper distance from the lower paper guide 2, 4,
Reference numeral 5 is a bearing on the carrying side, which supports the carrying roller 6 and the sub-carrying roller 7. These carrier-side bearings 4 and 5 are also fixed to the bottom plate 17.

FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, and FIG. 3 is a sectional view taken along the line 2-2 when the carriage 19 is in the state of the two-dot chain line which is the recording position in FIG. FIG. 1 to 3, the sub-conveyance roller 7 has a structure in which a rubber member is integrally fixed around a metal shaft 23, and a paper pressing member 12 described later is provided at both ends of the shaft 23. It is rotatably supported. Further, the sub-conveyance roller 7 is pressed against the conveyance roller 6 by a pressure mechanism (not shown). Therefore, when the conveyance roller 6 is rotated by a driving mechanism described later, the sub-conveyance roller 7 also rotates accordingly. This means that, for example, if the conveying roller 6 rotates in the direction of arrow Q, the sub-conveying roller 7 rotates in the direction of arrow P. At this time, when the recording material 1 is fed between the conveying roller 6 and the sub-conveying roller 7, the recording material 1 is fed in the direction of arrow A.

1 to 3, sheet discharge side bearings 8 and 9 are arranged on the sheet discharge side facing the conveying side bearings 4 and 5 with the platen 14 interposed therebetween. These paper discharge side bearings 8 and 9
Is also fixed to the bottom plate 17. The sheet discharge side bearings 8 and 9 pivotally support the sheet discharge roller 10 and the secondary sheet discharge roller 11. Similarly to the sub-conveyance roller 7, the sub-paper ejection roller 11 also has a structure in which a rubber member is integrally fixed around a metal shaft 24. A paper pressing member 13, which will be described later, is rotatably supported at both ends of the shaft 24.

Further, the sub-paper ejection roller 11 is pressed against the paper ejection roller 10 by a pressure mechanism (not shown). Therefore, when the paper ejection roller 10 is rotated by a rotational driving force by a drive mechanism described later. Therefore, the secondary paper discharge roller 11 also rotates, and the rotation direction is the arrow S direction for the paper discharge roller 10 and the arrow R direction for the secondary paper discharge roller 11. Here, since the recording material 1 is sandwiched between the transport roller 6 and the secondary transport roller 7 and between the paper discharge roller 10 and the secondary paper discharge roller 11, respectively, the transport roller 6 and the secondary discharge roller 11 are driven by a drive mechanism described later. When the paper roller 10 is rotationally driven, the recording material 1 is conveyed in the arrow A direction.

In FIGS. 1 to 3, reference numeral 12 denotes a conveying-side paper pressing member rotatably supported on both ends of a shaft 23 of the sub-conveying roller 7, and 13 denotes both ends of a shaft 24 of the sub-discharging roller 11. The paper pressing members 12 and 13 are rotatably pivotally supported, and the paper pressing members 12 and 13 are made of a hard material such as metal. Further, the paper discharge side paper pressing member 13 is urged in the direction of arrow E in the figure by the spring 25, abuts on a stopper portion (not shown), and an appropriate gap (passing the recording material) between the platen 14 and the platen 14. Form a space). Reference numeral 14 is a platen arranged between the transport roller 6 and the paper discharge roller 10. The platen 14 is also fixed to the bottom plate 17. In FIG. 1, reference numeral 15 denotes a bottom plate which is arranged in the vicinity of the discharge roller 10.
A paper discharge guide fixed at 16 is a conveyance motor fixed to the bottom plate 17 to supply a rotational driving force to the conveyance roller 6 and the paper ejection roller 10.

In FIGS. 1 and 3, a guide shaft 18 extending parallel to the axis of the carrying roller 6 is installed at a position closer to the paper cassette (not shown) than the carrying roller 6.
Both ends of the guide shaft 18 are fixed to side plates (not shown). A carriage 19 is movably guided and supported on the guide shaft 18, and head cartridges 20a, 20 of four different ink colors are provided on the carriage 19.
b, 20c, 20d are attached. Each head cartridge 20 is a replaceable cartridge in which a recording head and an ink tank are integrated, has a plurality of ejection ports on the platen 14 side, and ejects ink toward the platen 14 side through an opening at the bottom of the carriage 19. Can be discharged.

The recording means (recording head) 20 is an ink jet recording head for ejecting ink by utilizing heat energy, and is provided with an electrothermal converter for generating heat energy. In addition, the recording head 2
No. 0 causes film boiling in the ink due to the thermal energy applied by the electrothermal converter, and the pressure change due to the growth and contraction of bubbles generated at that time causes the ink to be ejected from the ejection port to perform recording. It is a thing.

FIG. 4 is a partial perspective view schematically showing the structure of the ink ejection portion of the recording head 20. In FIG. 4, the recording material 1 and a predetermined gap (for example, about 0.5 to
(About 2.0 mm) and the discharge port surface 81 facing each other,
A plurality of ejection openings 82 are formed at a predetermined pitch, and an electrothermal converter for generating energy for ejecting ink along the wall surface of each liquid passage 84 that connects the common liquid chamber 83 and each ejection opening 82 ( A heating resistor or the like) 85 is provided. The recording head 20 is mounted on the carriage 19 in such a positional relationship that the ejection ports 82 are arranged in a direction intersecting the main scanning direction (the reciprocal movement direction of the recording head 20). In this way, the corresponding electrothermal converter 85 is driven (energized) based on the image signal or the ejection signal to cause the ink in the liquid passage 84 to film-boil, and the ejection port 82 is caused by the pressure generated at that time.
A recording head 20 is configured to eject ink from the recording head.

In FIG. 1, the carriage 19 is at the home position during standby before recording, and a recovery unit (not shown) is arranged immediately below the carriage 19 at the home position. This recovery unit maintains the ink ejection portion of each recording head 20 in a good state,
It recovers to a good condition and is mounted on the bottom plate 17 in this embodiment. Reference numeral 22 is a main scanning motor that generates a driving force for moving the carriage 19 along the guide shaft 18.

In FIG. 3, the carriage 19 is provided with a paper discharge side roller 26 that rolls on the paper discharge side paper pressing member 13 and a transport side roller 27 that rolls on the transport side paper pressing member 12. ing. These rollers 26, 27 are arranged in the peripheral portion of the plurality of recording heads 20, and in the illustrated example, they are arranged at four positions, one at the front and the rear of the moving direction of the carriage 19, respectively.

Next, the operation of the ink jet recording apparatus will be described. In FIG. 1, the recording material 1 is fed in the direction of arrow A by a feeding mechanism (not shown) and guided between the lower paper guide 2 and the upper paper guide 3. The recording material 1 is further fed by the paper feeding mechanism (not shown) until the leading end of the recording material 1 reaches the nip portion between the conveying roller 6 and the sub-conveying roller 7 supported by the conveying side bearings 4, 5.

In FIG. 2, when the recording material 1 reaches the nip portion of the conveying rollers 6 and 7 by a paper feeding mechanism (not shown),
Rotational force is transmitted from the carry motor 16 to the carry roller 6. The conveying roller 6 and the sub-conveying roller 7 are rotationally driven by the transmitted rotational force, and the recording material 1 is sent out in the direction of arrow A. The recording material 1 sent out passes under the transport-side paper pressing member 12 while being guided by the platen 14 fixed to the bottom plate 17. Further, the recording material 1 sent out in the direction of the arrow A passes between the paper discharge side paper pressing member 13 and the platen 14. In this case, since the front end of the paper discharge side paper pressing member 13 is urged in the direction of arrow E in FIG. 2, the recording material 1 is set to pass easily.

In FIG. 2, the recording material 1 is nipped between the paper discharge roller 10 and the sub paper discharge roller 11 supported by the paper discharge side bearings 8 and 9 (FIG. 1) as the conveyance motor 16 further rotates. Be guided to. In this case, the conveying roller 6 is rotated and at the same time, the rotational force is transmitted from the conveying motor 16 to the paper discharge roller 10, and the transmitted rotational force causes the paper discharge roller 10 and the sub paper discharge roller 11 to be transmitted. Rotate in the directions of arrow R and arrow S, respectively, and the recording material 1 is sent out in the direction of arrow A. Then, the recording material 1 is stopped at a position where the recording material 1 is fed by a predetermined amount by the transport roller 6, the secondary transport roller 7, the paper discharge roller 10, and the secondary paper discharge roller 11, and is in a recording standby state. After the above-described paper feeding operation, the carriage 19 is moved in the direction of arrow C by the main scanning motor 22 in response to an input signal, whereby printing is performed.

Next, referring to FIG. 3, when the carriage 19 and each recording head 20 move to the recording position shown by the chain double-dashed line in FIG. 1, each recording head (head cartridge) 20, the platen 14, The positional relationship and operation of the recording material 1 and the paper pressing members 12 and 13 will be described.
In FIG. 3, the recording material 1 is sandwiched between a conveyance roller 6 and a sub-conveyance roller 7, and a paper discharge roller 10 and a sub-paper discharge roller 1 are provided.
It is also clamped to 1. Further, there is a platen 14 on the lower surface (back surface) of the recording material 1, and on the conveying side of the upper surface of the recording material 1, there is a conveying side paper pressing member 12 rotatably supported by both ends of a shaft 23. is there.

When the carriage 19 arrives at the recording position, the transport-side roller 27 provided on the carriage 19 presses the transport-side paper pressing member 12 to hold a part of the recording material 1. Further, in the other paper discharge side paper pressing member 13, similarly, the paper discharge side roller 26 provided on the carriage 19 resists the urging force of the spring 25 to press the paper discharge side paper pressing member 13. Thus, the other side portion of the recording material 1 is held down. Further, in order to ensure the landing accuracy of the ejected ink droplets on the recording material 1, it is necessary to dispose the ejection port surface 81 of the recording head 20 at a position close to the recording material 1.
Therefore, as shown in FIG. 3, the discharge port surface 81 is adjacent to the platen 14.

As a result, the distance between the paper discharge side paper pressing member 13 on the recording material 1 and the ejection port surface 81 of the recording head 20 is also as close as possible. In this state, the carriage 19 comes into contact with the paper-discharging side paper pressing member 13 and the paper-conveying side paper pressing member 12 via the paper-discharging side roller 26 and the carrying-side roller 27, so that the recording material 1 is moved over the recording material 1 by an arrow C in FIG. While moving in the direction, the recording operation is performed by ejecting ink droplets from the ejection port 82 of the recording head 20 toward the recording material 1. Thus the carriage 19
When one line is printed during the main scanning, the carriage 19 is moved in the opposite direction to return to the home position.

Therefore, the transport roller 6 and the paper discharge roller 1
0 is rotated by a predetermined amount, the recording material 1 is fed by a predetermined amount in the direction of arrow A, and its position (position for recording the next line)
Then, the recording material 1 is stopped and the next line is recorded on the recording material 1 by the recording head 20 while the main scanning of the carriage 19 is performed again. These series of operations are repeated for each line to record characters, images, etc. When the recording according to the input signal is completed, the recording material 1 is guided to the paper ejection guide 15 and ejected, and recording is performed. And the paper ejection is completed.

FIG. 5 is a schematic vertical sectional view showing a state at the time of recording operation of the first embodiment of the ink jet recording apparatus to which the present invention is applied, and FIG. 6 is a schematic view taken along line 6-6 in FIG. FIG. 7 is a partially enlarged view of a portion L in FIG. 6, and FIG. 8 is a view showing a carriage side roller and a paper discharge side roller of a carriage in a first embodiment of an ink jet recording apparatus to which the present invention is applied. FIG. 9 is a schematic side view of the holding structure, and FIG. 9 is a cross-sectional view taken along the line 9-9 in FIG. 8.

In FIGS. 8 and 9, the carriage 19
At the four corners on the lower side, forked portions 19a and 19b for pivotally supporting the paper discharge side roller 26 and the transport side roller 27, respectively.
Are formed. Holes 19c and 19d each having a U-shape and a horizontal part and having a T-shape as a whole are formed in each forked portion. Then, in each of the bifurcated portions 19a and 19b, the paper discharge side roller 26 and the transport side roller 27 have U of T-shaped holes 19c and 19d that oppose both ends of the center shaft 29.
It is rotatably supported by being inserted into the character portion. As a result, the carriage 19 is moved forward and backward in the moving direction.
The sheet discharge side rollers 26 and the two transport side rollers 27 are configured to rotate (roll) along with the main scanning movement (recording operation) of the carriage 19.

8 and 9, each roller 26, 2
A collar 35 is formed at one end of the shaft 29 of No. 7, and a retaining member 34 is fixed to the other end of the shaft 29, so that the shaft 29 is supported so as not to come off in the axial direction. Further, in the horizontal portions of the T-shaped holes 19c and 19d formed so as to face the bifurcated portions 19a and 19b at the four corners of the carriage 19, arc-shaped (bow-shaped) formed of a thin elastic material is provided. Elastic members (springs) 30 are attached. Then, each of the discharge side rollers 26 and each of the transport side rollers 27 have the elastic member 3
By abutting both ends of the shafts 29 with 0 and 30, they are urged toward the platen 14.

Resilient member 3 of each roller 26, 27
The biasing forces of 0 and 30 are set so as to balance with the quarter of the own weight of the carriage 19 and the plurality of recording heads (head cartridges) 20, and a force larger than this biasing force is applied to the rollers (26, 27). When actuated, the elastic member 3
The elastic deformation of 0 and 30 causes the rollers to move in the vertical direction. That is, each discharge side roller 2
6 and each of the transport-side rollers 27 are mounted such that they can slide in the direction of arrow W in FIG. 8 when a force larger than the total weight of the carriage including the carriage 19 and the recording head 20 is applied.

During normal recording, the rollers 2 on the discharge side
6 and each of the transport-side rollers 27 are provided on the carriage 19 respectively.
And the elastic weights of the plurality of recording heads (head cartridges) 20 are balanced with one-fourth of their own weight.
The axes 0 and 30 are not deformed, and the shafts 29 are kept in contact with the bottoms of the U-shaped portions of the T-shaped holes 19c and 19d of the carriage 19.

In FIG. 5, the carriage 19 is in a recordable position, and at this time, the recording material 1 is held by the conveying roller pairs 6 and 7 and the discharge roller pairs 10 and 11 as described above. Further, there is a platen 14 on the lower surface (rear surface) of the recording material 1, and each of the transport-side rollers 27 mounted on the carriage 19 presses the paper pressing member 12 to press a part of the recording material 1. ing. At the same time, the respective discharge side rollers 26 mounted on the carriage 19
By pressing the paper pressing member 13 against the spring 25, the other side of the recording material 1 is also pressed.

If the surface of the platen 14 has unevenness 14a as shown in FIG. 6, the weight of the carriage 19 and the head cartridge 20 is applied to the roller (the front transport side roller 27 in the illustrated example) passing through the unevenness 14a. Since a load larger than a quarter acts on the transport-side roller 27 and its shaft 29 in the arrow W direction (vertical direction) in the T-shaped hole 19c against the urging force of the elastic members 30, 30. It will slide. Similarly, the other rollers (the rear transport side roller 27 and the front and rear sheet discharge side rollers 26) also slide in the vertical direction when passing through the unevenness 14a.

Therefore, the unevenness 1 is formed on the surface of the platen 14.
Even when the carriage 4a is provided, the carriage 19 and the ejection port surface 81 of each of the recording heads 20 mounted on the carriage can always move (main scanning) while being parallel to the platen 14, and the ejection from the recording head 20 can be performed. There is no deviation in the landing position of the formed ink droplet on the recording material 1, and good image recording can be performed. In particular, in the case of color recording using a plurality of inks of different colors, it is possible to prevent the accuracy of landing positions of ink droplets of each color that are overprinted from decreasing, which is extremely effective in improving the recording quality of color images. is there.

FIG. 10 is a schematic side view of the structure for holding the carriage-side roller and the paper-discharging side roller in the second embodiment of the ink jet recording apparatus to which the present invention is applied, and FIG. 11 is a line 11 in FIG. FIG. 11 is a sectional view taken along line -11.
10 and 11, bifurcated portions 19a and 19b for pivotally supporting the discharge side roller 26 and the transport side roller 27 are formed at the four lower corners of the carriage 19, respectively. U-shaped holes 19e and 19f facing each other are formed in the bifurcated portion. Then, in each of the bifurcated portions 19a and 19b, the discharge side roller 26 and the transport side roller 27 are fitted and inserted into the U-shaped holes 19e and 19f facing each other at both ends of the center shaft 29. , Is rotatably supported. As a result, the two discharge-side rollers 26 and the two transport-side rollers 27 before and after the carriage 19 in the moving direction are rotated (rolled) along with the main scanning movement (recording operation) of the carriage 19. It is configured.

10 and 11, each roller 2
A flange 35 is formed at one end of the shaft 29 of the shaft 6, 27.
A retaining member 34 is fixed to the other end of the shaft 9,
9 is supported so as not to come off in the axial direction. Further, a shaft 29 is provided above the U-shaped holes 19e and 19f formed in the bifurcated portions 19a and 19b at the four corners of the carriage 19.
The recesses 36, 36 are formed in the direction orthogonal to
A spring 3 for elastically urging the shaft 29 in 6, 36.
3 and 33 are attached. That is, each discharge side roller 2
6 and each of the transport-side rollers 27 are biased toward the platen 14 by the biasing force of the springs 33, 33.

The springs 33 of the rollers 26 and 27,
The biasing force of 33 is set so as to balance with the quarter of the own weight of the carriage 19 and the plurality of recording heads (head cartridges) 20, and when a force greater than this biasing force acts on the rollers (26, 27). By elastically deforming the springs 33, 33, the roller moves in the vertical direction. That is, as in the case of the above-described first embodiment, each of the discharge side rollers 26 and each of the transport side rollers 27 is subjected to a force larger than the total weight of the carriage including the carriage 19 and the recording head 20 in FIG. Arrow W
It is mounted so that it can slide in any direction.

The second embodiment of FIGS. 10 and 11 has substantially the same structure as that of the above-described first embodiment in other parts, and detailed description thereof will be omitted. Therefore, also in this embodiment, the same operational effect as in the case of the above-mentioned first embodiment can be obtained. That is, during normal recording, the paper discharge side rollers 26 and the transport side rollers 27 are in balance with the carriage 19 and a quarter of the own weight of the plurality of recording heads (head cartridges) 20, respectively. 33, 33 is not deformed, each shaft 29
Keeps contacting the bottoms of the U-shaped holes 19e and 19f of the carriage 19.

When the carriage 19 is at the recordable position, the recording material 1 is nipped by the conveying roller pairs 6 and 7 and the discharge roller pairs 10 and 11, as described with reference to FIG. There is a platen 14 on the back surface of the recording material 1 and the recording material 1 is recorded on the recording head 20 by the conveyance side rollers 27 and the discharge side rollers 26 mounted on the carriage 19 pressing the respective paper pressing members 12 and 13. It is pressed on both sides of the area facing.

When the surface of the platen 14 has irregularities 14a as shown in FIG. 6, the carriage 19 and the head cartridge 20 are attached to a roller (either the transport side roller 27 or the discharge side roller 26) passing through the irregularity 14a. Since a load larger than a quarter of its own weight acts, the roller and its shaft 29 resist the urging force of the springs 33, 33 in the U-shaped holes 19e, 19f in the arrow W direction (vertical direction). Will slide on. Similarly, the other rollers slide in the vertical direction when passing through the unevenness 14a.

Therefore, according to this embodiment as well, even when the surface of the platen 14 has irregularities 14a, the ejection port surface 81 of the carriage 19 and each recording head 20 mounted on the carriage is always kept parallel to the platen 14. The recording head 20 can be moved (main scanning).
There is no deviation in the landing position of the ink droplets ejected from the recording material 1, and an effect that good image recording can be performed is obtained. Further, in the case of color recording using a plurality of inks of different colors, it is possible to prevent the accuracy of landing positions of the ink droplets of each color to be overlaid, and it is extremely effective for improving the recording quality of color images. Is.

According to the embodiments described above, the rollers 27 and 26 of the carriage 19 having the recording head 20 roll on the paper pressing members 12 and 13, and the paper pressing member 1
In an ink jet recording apparatus in which the recording material 1 is sandwiched between the recording materials 1 and 2 and the platen 14 and recording is performed on the recording material 1, the platen 14 is affected by variations in component accuracy and assembly accuracy.
Even if unevenness occurs on the surface of the sheet, the discharge side roller 26 and the transport side roller 2 follow the unevenness of the platen 14 during recording.
By moving up and down 7, the ejection port surface 8 of the recording head 20
1 can always be kept parallel to the platen 14,
Ink landing accuracy can be improved, and color misregistration or the like can be reliably prevented when a plurality of recording heads are used as in color recording.

In each of the above-described embodiments, the case of color recording using a plurality of recording heads for recording in different colors has been described. However, the present invention is a serial recording system in which the recording heads are moved in the main scanning direction. If so, the same applies to single-color recording for recording with one recording head, gradation recording using a plurality of recording heads for recording the same color with different densities, and also for a recording device combining these. The same effect can be achieved.

Further, according to the present invention, when a replaceable head cartridge in which a recording head and an ink tank are integrated is used, or when the recording head and the ink tank are separated, and the space between them is connected by an ink supply tube or the like. The same can be applied to any arrangement of the recording head and the ink tank, and similar effects can be obtained.

The present invention can be applied to an ink jet recording apparatus using a recording means (recording head) using an electromechanical transducer such as a piezo element, but among them, thermal energy is used. Then, an excellent effect is brought about in an ink jet recording apparatus which uses a recording means of a method of ejecting ink. This is because such a system can achieve high density recording and high definition recording.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
This is preferably done using the basic principles disclosed in 796. This method can be applied to both the so-called on-demand type and the continuous type, but particularly in the case of the on-demand type, a liquid (ink) is used.
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. , Generates heat energy in the electrothermal converter to cause film boiling on the heat acting surface of the recording means (recording head), and as a result, bubbles can be formed in the liquid (ink) in a one-to-one correspondence with this drive signal. So effective.

Due to the growth and contraction of the bubbles, liquid (ink) is ejected through the ejection openings to form at least one droplet. It is more preferable to make 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 this pulse-shaped drive signal, US Pat.
Those described in US Pat. Nos. 4,633,359 and 4,345,262 are suitable. Incidentally, US Pat. No. 43131 of the invention relating to the rate of temperature rise of the heat acting surface.
If the conditions described in the specification of No. 24 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. US Pat. No. 4,558,333, US Pat. No. 4,558,333, which discloses a configuration in which a heat acting portion is arranged in a bending region.
A configuration using the specification of No. 459600 is also included in the present invention. In addition, Japanese Laid-Open Patent Publication No. 123670/1984 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters, and an opening for absorbing a pressure wave of thermal energy. The present invention is also effective as a structure based on Japanese Patent Laid-Open No. 138461/1984, which discloses a structure in which the discharge section is associated with the discharge section. That is, according to the present invention, recording can be reliably and efficiently performed regardless of the form of the recording head.

According to the present invention, in the case of a serial type ink jet recording apparatus, a recording head fixed to the apparatus main body, or by being attached to the apparatus main body, electrical connection with the apparatus main body or ink from the apparatus main body is generated. This is also effective when a replaceable chip-type recording head that can be supplied or a cartridge-type recording head in which an ink tank is integrally provided in the recording head itself is used.

Further, it is preferable to add recovery means, preliminary auxiliary means, etc. to the recording head provided as a constitution of the recording apparatus in the present invention because the effect of the present invention can be further stabilized. If you list these specifically,
Capping means, cleaning means, pressurizing or suctioning means, electrothermal converter or other heating element or preheating means by a combination thereof, and ejection different from recording are applied to the recording head. Performing the preliminary ejection mode is also effective for stable recording.

As described above, regarding the type and number of recording heads mounted, for example, only one is provided corresponding to a single color ink, or a plurality of recording heads having different recording colors and densities are provided. A plurality of inks may be provided corresponding to the ink. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be either the recording head is integrally configured or a combination of a plurality of recording heads may be used. The present invention is extremely effective for an apparatus provided with at least one of color colors or full colors by color mixing.

In addition, in the above-described embodiments of the present invention, the ink is described as a liquid, but it is an ink that solidifies at room temperature or lower and that softens or liquefies at room temperature, or an ink jet. In the method, the temperature of the ink itself is generally adjusted within a range of 30 ° C. or higher and 70 ° C. or lower to control the temperature of the ink so that the viscosity of the ink is within a stable ejection range. It may be in a liquid form. in addition,
Whether the temperature rise due to thermal energy is positively used as the energy for changing the state of the ink from the solid state to the liquid state, or the ink that solidifies when left standing for the purpose of preventing evaporation of the ink is used. In any case, the ink is liquefied by applying the thermal energy according to the recording signal and the liquid ink is ejected,
The present invention is also applicable to the case of using an ink that has a property of being liquefied only by thermal energy, such as one that has already started to solidify when it reaches the recording medium.

The ink in such a case is described in JP-A-54-54.
As described in JP-A-56847 or JP-A-60-71260, a form in which the electrothermal converter is opposed to a liquid sheet or a solid material held in the recesses or through holes of the porous sheet. May be In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as the form of the ink jet recording apparatus according to the present invention, besides the one used as an image output terminal of an information processing apparatus such as a computer, a copying apparatus combined with a reader or the like, and a facsimile apparatus having a transmitting / receiving function. And the like may be used.

[0056]

As is apparent from the above description, according to the present invention, in the ink jet recording apparatus for recording the recording material on the platen by ejecting ink from the recording means mounted on the carriage, the carriage is recording. Has a carriage roller that presses the recording material onto the platen via a paper pressing member, and the carriage roller is biased and held by the carriage by an elastic member. Even if the platen surface has irregularities, the interval and parallelism between the ejection port surface of the recording unit and the platen surface disposed opposite thereto can always be maintained properly during recording, and the ink landing accuracy is reduced. There is provided an ink jet recording apparatus capable of preventing the image deterioration and preventing image deterioration such as color shift.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a main part configuration of an embodiment of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic vertical sectional view taken along the line 2-2 in FIG.

FIG. 3 is a schematic cross-sectional view taken along the line 2-2 when the carriage is at the position of the alternate long and two short dashes line in FIG.

FIG. 4 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording unit in FIG.

FIG. 5 is a schematic vertical cross-sectional view showing a state when the carriage is at a recordable position in the inkjet recording apparatus to which the present invention is applied.

FIG. 6 is a schematic front view of the carriage taken along line 6-6 in FIG.

7 is an enlarged view of a portion L in FIG.

FIG. 8 is a partial front view schematically showing the state of attachment of the paper discharge side roller and the transport side roller of the first embodiment of the inkjet recording apparatus to which the present invention is applied.

9 is a cross-sectional view taken along the line 9-9 in FIG.

FIG. 10 is a partial front view schematically showing a mounting state of the paper discharge side roller and the transport side roller of the second embodiment of the inkjet recording apparatus to which the present invention is applied.

12 is a cross-sectional view taken along the line 11-11 in FIG.

[Explanation of symbols]

 1 Recording Material 6 Conveying Roller 7 Secondary Conveying Roller 10 Paper Ejecting Roller 11 Secondary Ejecting Roller 12 Conveying Side Paper Holding Member 13 Paper Ejecting Side Paper Holding Member 14 Platen 16 Conveying Motor 17 Bottom Plate 18 Guide Axis 19 Carriage 20 Recording Means (Recording Head) 22 Main scanning motor 23 Secondary transport roller shaft 24 Secondary discharge roller shaft 25 Spring 26 Paper discharge side roller 27 Transport side roller 29 Axis 30 Elastic member 33 Spring 36 Recess

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[Procedure amendment]

[Submission date] May 13, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a main part configuration of an embodiment of an inkjet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic vertical sectional view taken along the line 2-2 in FIG.

FIG. 3 is a schematic cross-sectional view taken along the line 2-2 when the carriage is at the position of the alternate long and two short dashes line in FIG.

FIG. 4 is a partial perspective view schematically showing the structure of an ink ejection portion of the recording unit in FIG.

FIG. 5 is a schematic vertical cross-sectional view showing a state when the carriage is at a recordable position in the inkjet recording apparatus to which the present invention is applied.

FIG. 6 is a schematic front view of the carriage taken along line 6-6 in FIG.

7 is an enlarged view of a portion L in FIG.

FIG. 8 is a partial front view schematically showing the state of attachment of the paper discharge side roller and the transport side roller of the first embodiment of the inkjet recording apparatus to which the present invention is applied.

9 is a cross-sectional view taken along the line 9-9 in FIG.

FIG. 10 is a partial front view schematically showing a mounting state of the paper discharge side roller and the transport side roller of the second embodiment of the inkjet recording apparatus to which the present invention is applied.

11 is a cross-sectional view taken along the line 11-11 in FIG.

[Explanation of Codes] 1 Recording material 6 Conveying roller 7 Sub-conveying roller 10 Discharging roller 11 Sub-discharging roller 12 Conveying side paper pressing member 13 Discharging side paper pressing member 14 Platen 16 Conveying motor 17 Bottom plate 18 Guide shaft 19 Carriage 20 recording means (recording head) 22 main scanning motor 23 auxiliary transport roller shaft 24 secondary discharge roller shaft 25 spring 26 discharge side roller 27 transport side roller 29 shaft 30 elastic member 33 spring 36 concave portion

Claims (3)

[Claims] 1. An inkjet recording apparatus for recording ink on a recording material on a platen by ejecting ink from recording means mounted on the carriage, wherein the carriage transfers the recording material onto the platen via a paper pressing member during recording. An ink jet recording apparatus comprising: a carriage roller to be pressed, wherein the carriage roller is biased and held by the carriage by an elastic member. 2. The ink jet recording apparatus according to claim 1, wherein the recording means is an ink jet recording means including an electrothermal converter that generates thermal energy used for ejecting ink. 3. The ink jet recording apparatus according to claim 2, wherein the recording unit ejects the ink from the ejection port by utilizing film boiling generated in the ink by the thermal energy generated by the electrothermal converter.