JPH10250057A - Ink jet recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably improve shot accuracy of an ink droplet and to improve quality of a recorded image by urging a support means in a direction for approaching it to a recording medium, and specifying a distance between the support means and the medium, thereby always maintaining a gap between the means and the medium constant. SOLUTION: When there is a recording medium 1, a distance (between sheets) between a discharge port surface of a recording means 50 and a recording surface of the medium 1 is always held at a constant value of the distance irrespective of presence or absence of waviness of the medium 1 due to thickness or swell of the medium 1. A slide member 13 constitutes a support means for supporting a recording means 30 to approach to or separate from the medium 1. A compression sporing 14 constitutes an urging means for urging the member 13 in a direction for approaching the medium 1. A roller 13 constitutes a position specifying means for specifying a distance between the member 13 and the medium 1 in contact with the medium 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an ink jet recording apparatus for recording by discharging ink from a recording means to a recording medium.

[0002]

2. Description of the Related Art A recording device having a function such as a printer, a copying machine, a facsimile or the like, or a recording device used as an output device such as a composite electronic device including a computer or a word processor or a workstation, is based on paper based on the recording information. It is configured to record an image (including characters and symbols) on a recording medium (recording material) such as a recording medium or a plastic thin plate. The recording apparatus, depending on the recording method, inkjet type, wire dot type, thermal type,
It can be divided into laser beam type and the like.

In a serial type recording apparatus that performs recording while performing main scanning in a direction crossing the transport direction (sub-scanning direction) of the recording medium, the recording medium is set at a predetermined recording position and then moved along the recording medium. By combining the recording operation of the recording means and the transport operation of feeding the recording medium in a direction crossing the moving direction of the recording means, the recording of the entire recording medium is performed.

On the other hand, in a line type recording apparatus that performs recording only by sub-scanning in which a recording medium is transported in a transport direction, the recording medium is set at a predetermined recording position, and recording for one line is continuously performed collectively. While feeding a predetermined amount of paper (pitch feed), an image is recorded on the entire recording medium.

[0005] Among the above recording apparatuses, an ink jet recording apparatus (ink jet recording apparatus) performs recording by discharging ink from a recording means (recording head) onto a recording medium, so that it is easy to make the recording means compact. It can record high-definition images at high speed, can be recorded on plain paper without requiring special processing, running cost is low, and because it is a non-impact method, there is little noise, and It has the advantage that it is easy to record a color image using multicolor inks. Above all, a line type using a full multi-type recording means in which a large number of discharge ports are arranged in the paper width direction can further increase the recording speed.

[0006] In particular, an ink jet type recording means (recording head) for discharging ink by using thermal energy,
Through a semiconductor manufacturing process such as etching, vapor deposition, sputtering, etc., an electrothermal converter, an electrode,
By forming the liquid path wall, the top plate, and the like, it is possible to easily manufacture a device having a high-density liquid path arrangement (discharge port arrangement), and to further reduce the size. On the other hand, there are various demands for the material of a recording medium (recording material). In recent years, in addition to ordinary recording media such as paper and resin thin plates (OHP, etc.), thin paper or processed paper (for filing) has been used. Bunch holes, perforated paper, paper of any shape, etc.) have been required to be used.

FIGS. 6 and 7 are schematic longitudinal sectional views showing an example of the structure of a conventional ink jet recording apparatus. FIG. 6 shows a state during recording, and FIG. 7 shows a state immediately after a recording medium is supplied. . 6 and 7, reference numeral 101 denotes a recording medium such as a recording sheet or a plastic thin plate, and reference numerals 102 and 103 denote a pair of rollers (conveying roller and pinch roller) which form conveying means disposed on the upstream side in the recording medium conveying direction. Yes, 10
Reference numerals 4 and 105 denote a pair of rollers (conveying roller and pinch roller) which form conveying means disposed downstream in the recording medium conveying direction. The recording medium 101 has these two locations (2
Pairs) and are conveyed by a conveying means comprising a pair of rollers.

Reference numeral 106 denotes a guide member for regulating the transport path of the recording medium, and 107 denotes the two pairs of transport rollers 102 and 10.
3 and recording means (recording head) arranged between 104 and 105. An ink ejection section having a plurality of ejection ports arranged in the recording medium transport direction is provided on the lower surface of the recording head 107 in the drawing (the surface facing the recording medium 101). 108 is an ink tank. In the illustrated example, a replaceable head cartridge is configured by integrating the recording head 107 and the ink tank 108.
In this document, in addition to calling only the recording head as recording means,
A head cartridge (or ink cartridge) including the recording head 107 and the ink tank 108 integrated as in this embodiment is also referred to as a recording unit or a recording head.

Referring to FIGS. 6 and 7, a recording head 107 is shown.
And a recording means including an ink tank 108 is mounted (held) on a carriage 109, and the carriage 109 is moved substantially in the recording medium conveyance direction by carriage guides 110 and 111 arranged substantially parallel to the rotation axes of the conveyance rollers 102 to 105. It is guided and supported so as to be movable in a direction perpendicular to the direction. In such a configuration, the supplied (inserted) recording medium 101 is transported by two pairs of transport rollers 102, 103 and 10.
The print head 107 is intermittently conveyed and stopped by nipping at 4 and 105, and while stopped, the recording head 107 is moved (main scanning) in a direction substantially perpendicular to the conveyance direction between the two pairs of conveyance rollers, based on the data. Thus, an image for one line is recorded on the recording medium 101.

FIG. 8 is a longitudinal sectional view showing a schematic structure of an ink jet recording apparatus described in Japanese Patent Application Laid-Open No. 3-114,838. 8, reference numeral 120 denotes a recording medium such as recording paper; 121, a platen roller; 122, an upstream pinch roller (paper feed roller); and 123, a downstream pinch roller (paper discharge roller). 124 is a recording means (recording head), 125 is an ink tank, 126 is a slide table, 127 is a linear movement pulse motor, 128 is a carriage, and 129 is a carriage guide.

In the ink jet recording apparatus having the configuration shown in FIG. 8, the distance between the recording means 124 and the recording medium 120 is changed by controlling the driving of the linear moving pulse motor 127 in accordance with the frequency of ink ejection. ing. That is, immediately after printing a line with a high ink ejection frequency, the interval between the recording unit 124 and the recording medium 120 is increased because the deformation due to swelling of the recording medium 120 is large, and immediately after a line with a low ink ejection frequency is recorded. On the contrary, the distance between the recording means 124 and the recording medium 120 is reduced.

[0012]

Conventionally, various attempts have been made to improve the recording quality (image quality) of an ink jet recording apparatus which performs recording on a recording medium by discharging ink droplets. For example, it has been practiced to improve the definition of the recording head itself (to increase the density of the ejection port arrangement) and to improve the landing accuracy of ink droplets (dots) on a recording medium. In general, in order to improve the landing accuracy, the distance between the front surface of the recording head and the surface of the recording medium (hereinafter, also simply referred to as a gap) must be suppressed to about 0.3 to 0.7 mm.

On the other hand, in recent years, there has been a demand for a function capable of recording on a thick recording medium such as a postcard or an envelope in addition to a recording sheet which is generally used. It is beginning to cover a wide range from 0.05 mm to about 0.6 mm. Further, in an ink jet recording apparatus, since a liquid called ink is attached to a recording medium, when paper or the like is used as a recording medium,
After recording, the recording medium may swell and deform into a wavy shape.

Accordingly, in the ink jet recording apparatus shown in FIGS. 6 and 7, when the gap between the recording head 107 and the recording medium 101 is narrowed in order to improve the positional accuracy of the ink droplet landing on the recording medium 101, this recording is performed. There is a risk that the ejection port surface of the head will come into contact with the recording medium and stain the recording medium 101. Therefore, in order to enable recording on a recording medium having any thickness, the gap needs to be relatively large, about 1 mm, assuming the worst case. In this case, on the contrary, the accuracy of the landing position cannot be ensured, and the dot position shifts and the image quality deteriorates.

According to the ink jet recording apparatus shown in FIG. 8, since the interval between the recording head and the recording medium is controlled in accordance with the ejection frequency, it is possible to solve the problems in the ink jet recording apparatus shown in FIGS. It is possible. That is, immediately after recording a line having a high ejection frequency, the recording head 1 is largely deformed due to swelling of the recording paper 120.
Immediately after printing the line with a low ejection frequency by increasing the interval between the recording paper 120 and the recording paper 120, the deformation due to the swelling of the recording paper 120 is small.
Can be made smaller.

However, the configuration shown in FIG. 8 has a problem that the control is complicated and the manufacturing cost is increased. Further, it is necessary to provide a paper thickness detecting means in order to cope with recording papers of various thicknesses, which also complicates the control and increases the cost.

In both the conventional example shown in FIGS. 6 and 7 and the conventional example shown in FIG. 8, when recording is performed on the leading end of the supplied recording medium (recording paper), the recording paper is formed by a pair of rollers as shown in FIG. , The leading edge of the recording paper may rise and come into contact with the recording head, and therefore, the recording paper may be soiled or the recording head may be damaged.
In order to avoid this, it is necessary to increase the gap between the recording head and the recording paper. However, as described above, the positional accuracy of the ink droplet landing is reduced and the quality of the recorded image is reduced. In recent years, the number of ejection ports tends to increase in order to shorten the recording time, and therefore, the length of the recording head in the transport direction tends to increase. Therefore,
The interval between two pairs of transport rollers disposed on the upstream side and the downstream side in the transport direction with the recording head therebetween is increased, and the problem caused by the rising of the leading edge of the recording paper is becoming more serious.

The present invention has been made in view of such technical problems, and it is an object of the present invention to provide a simple structure that does not require an extra control system and has an effect on swelling and waving of a recording medium. Provided is an ink jet recording apparatus capable of always maintaining a constant gap between a recording unit and a recording medium without receiving the recording medium, stably improving the landing accuracy of ink droplets, and improving the image quality of a recorded image. It is.

[0019]

According to a first aspect of the present invention, there is provided an ink jet recording apparatus for performing recording by discharging ink from a recording means onto a recording medium.
Supporting means for supporting the recording means so as to approach and separate from the recording medium; urging means for urging the supporting means in a direction to approach the recording medium; and supporting the recording medium in contact with the recording medium. And a position regulating means for regulating a distance between the recording medium and the recording medium.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view in the front-rear direction of a first embodiment of an ink jet recording apparatus to which the present invention is applied, and FIG. 2 is a longitudinal sectional view in the left-right direction of the ink jet recording apparatus of FIG. 1 and 2, reference numeral 1 denotes a recording medium such as a recording paper or a plastic thin plate, 2 denotes a conveying roller disposed upstream in a recording medium conveying direction, and 3 denotes a conveying roller for generating a frictional conveying force. The pinch rollers 4 to be pressed are transport rollers arranged on the downstream side in the recording medium transport direction, and the pinch rollers 5 are pressed to the transport rollers 4 to generate frictional transport force. The rollers 2, 3
(A pair of rollers) constitutes an upstream conveying roller pair, and a pair of the rollers 4 and 5 (a pair of rollers) constitutes a downstream conveying roller pair. The sheet is nipped by a conveying means composed of two (two) pairs of rollers, and is conveyed in the direction of arrow A by rotating these rollers in the direction of arrow.

In FIGS. 1 and 2, reference numeral 6 denotes a guide member that regulates the conveyance path of the recording medium 1, reference numeral 7 denotes a recording means (recording head) having a plurality of ejection ports arranged in the conveyance direction, and reference numeral 8 denotes a recording head.
Denotes an ink tank in which recording ink is stored, and 9 denotes a carriage on which the recording means 7 and the ink tank 8 are mounted. In the present embodiment, the recording means 7 and the ink tank 8 are integrated to constitute a replaceable ink cartridge (head cartridge) 50. In this document, the recording means 7 and the ink tank 8 are included. Are also referred to as recording means 50 or recording head 50 in the same manner.

The carriage 9 is provided with each of the transport rollers 2, 4
Are guided and supported so as to be movable (main scanning) along a pair of carriage guides 10 and 11 installed substantially parallel to the rotation axis of the carriage. That is, the moving direction of the carriage 9 is
Is set in a direction substantially orthogonal to the carrying direction of the sheet. Also,
The guide member 6 is disposed between the two pairs of transport rollers 2, 3, 4 and 5, and the recording means 50 is positioned at a position facing the guide member 6 (accordingly, the two pairs of transport rollers 2). (Position between them). An ink discharge section having a plurality of discharge ports arranged in the recording medium transport direction is provided on the lower surface of the recording head (recording means) 7 in the drawing (the surface facing the recording medium 1).

In such a configuration, the supplied (inserted) recording medium 1 is intermittently conveyed and stopped by being sandwiched between two pairs of conveying rollers 2, 3, 4 and 5, and during the stop, the conveying direction is changed. The recording head 50 is moved (main scanning) in a direction substantially orthogonal to the recording head 5 and synchronized with this movement, based on the data.
By driving 0, an image for one line is recorded on the recording medium 1. When printing for one line is completed, the printing medium 1 is conveyed (sub-scanning) by a predetermined pitch, and printing for the next line is executed. Hereinafter, these operations are repeated and the entire area of the recording medium 1 is recorded.

The recording means (recording head) 50 is an ink jet recording means for discharging ink using thermal energy, and is provided with an electrothermal converter for generating thermal energy. Further, the recording head 50
According to the method, recording is performed by ejecting ink from an ejection port using a pressure change caused by growth and shrinkage of bubbles caused by film boiling caused by heat energy applied by the electrothermal transducer.

FIG. 3 is a partial perspective view schematically showing the structure of the ink ejection section of the recording means (recording head) 50. In FIG. 3, a predetermined gap (for example, about 0.
A plurality of discharge ports 82 are formed at a predetermined pitch on a discharge port surface 81 facing at a distance of about 3 to 2.0 mm), and each liquid path 84 connects the common liquid chamber 83 and each discharge port 82. An electrothermal converter (heat-generating resistor or the like) 85 for generating energy for ink ejection is provided along the wall surface.
The recording head 50 is mounted on the carriage 9 such that the ejection openings 82 are arranged in a direction intersecting with the moving direction (main scanning direction) of the carriage 9. Thus,
A recording means for driving (energizing) the corresponding electrothermal transducer 85 based on an image signal or a discharge signal to cause the ink in the liquid path 84 to boil, and to discharge the ink from the discharge port 82 by the pressure generated at that time. (Recording head) 50 is configured.

In FIG. 1 and FIG. 2, a recording means 50 comprising a recording head 7 and an ink tank 8 is a sliding member 1.
3, the outer periphery of the slide member 13 is fitted in a vertical rectangular hole 9b formed in the carriage 9, and the slide member 13 keeps the recording posture while maintaining the parallel posture with the recording medium 1. The medium 1 is held by the carriage 9 so as to be smoothly movable in a direction perpendicular to the recording surface (surface = paper surface). The slide member 13 has a compression spring 14 mounted between the upper end thereof and the carriage 9.
Is pressed (biased) toward the recording medium 1 (downward in the figure). A roller 12 is rotatably attached to a protrusion 13a provided on the bottom of the slide member 13 via a shaft 12a. The rotation shaft 12a of the roller 12 is provided in a direction substantially orthogonal to the axial direction of the carriage guides 10, 11.

The lower end of the roller 12 is
Of the recording medium 1 (downward in the figure) from the lower end surface (ejection port surface 81) of the recording medium 1 by a distance L. This distance L corresponds to the flight distance of the ink droplet ejected from the ejection port 82, and is set to an optimum value of, for example, about 0.3 to 0.7 mm. The slide member 13 holding the recording head 50 is compressed by a compression spring 14 into a recording medium (recording paper).
1, the roller 12 supported by the bottom of the slide member 13 is pressed against the guide member 6 when the recording paper 1 is not present. On the other hand, when the recording paper 1 is present, the roller 12 is constantly pressed against the recording paper 1. That is, when the recording medium 1 is present, the distance (paper interval) between the discharge port surface 81 of the recording means 50 and the recording surface of the recording medium 1 is determined by the thickness of the recording medium 1 and the presence or absence of undulation of the recording medium 1. Irrespective of the above, the distance L is always kept at a constant value.

The slide member 13 constitutes a support means for supporting the recording means 50 so as to be able to approach and separate from the recording medium 1, and the compression spring 14 applies the slide member 13 in a direction approaching the recording medium 1. Constituting biasing means for biasing,
The roller 12 constitutes a position regulating unit that contacts the recording medium 1 and regulates the distance between the slide member 13 (same as the recording unit 50) and the recording medium 1.

The roller 1 as the position regulating means
The position at which 2 contacts (presses) the recording medium (recording paper) 1
As shown in FIG. 1, the two pairs of rollers 2, 3, 4, 5,
Among the pair of rollers (conveying roller pair) 2 and 3 disposed on the upstream side in the recording medium conveying direction and downstream of a tangent line where the recording medium 1 contacts, and the upstream end of the ink ejection unit of the recording means 50 (For example, the position of the discharge port closest to the pair of rollers 2 and 3 on the upstream side) is selected at a position on the upstream side. Therefore, the roller 12 does not come into contact with the ink adhered to the surface of the recording medium (recording paper) 1 after recording.

Next, the operation of the ink jet recording apparatus shown in FIGS. 1 and 2 will be described. The recording paper 1 stacked and stored in a paper feed tray (not shown) is separated from the uppermost layer by a mechanism (not shown), and the separated recording paper 1 is fed by a paper feeding mechanism (not shown). The front end of the roller 1 is held by a contact portion between the transport roller 2 and the pinch roller 3 on the upstream side. Next, the recording paper 1 is conveyed to a predetermined position facing the recording head 7 by rotating the conveying roller 2 by a driving source (not shown) (a conveying motor or the like), and the recording is started by stopping the conveying roller 2 there. Set to position.

While the recording paper 1 is stopped, the carriage 9 is driven by a driving source (not shown) (carriage motor or the like).
Is moved along the carriage guides 10 and 11 in a direction substantially perpendicular to the transport direction (main scanning), and the printhead 50 is driven based on print information in synchronization with the movement of the carriage 9, so that the print head 50 Eject ink drops,
Thereby, recording (recording for one line) is performed on the recording paper 1. At this time, the roller 12 as a position regulating means
Rolls on the surface of the recording paper (recording medium) 1 (contact rotation)
However, the distance (gap) between the recording head 17 and the recording paper 1 is always kept constant.

The recording head 17 is moved by the movement of the carriage 9.
When the sheet passes through the widthwise end of the recording sheet 1 and comes out of the recording area, all the rollers 12 come into contact with the guide member 6, and when the state is reached, the movement of the carriage 9 stops. During this state, that is, while the roller 12 is at the position where the recording paper 1 is removed, the conveyance roller 2 and the pinch roller 3 are rotated by a predetermined amount to convey the recording paper 1 by a predetermined amount (predetermined pitch) (paper feed). ) And set it at the recording position of the next line. When the recording paper 1 is conveyed, the rollers 12 serving as position regulating means are retracted out of the recording paper 1 and do not hinder the conveyance. After stopping the recording paper 1 at the position of the next line, the recording of the next line is performed in the same manner as described above. By repeating such recording and conveyance a desired number of times, recording is performed in a desired range of the recording paper 1.

Normally, during recording, the leading end of the recording paper (recording medium) 1 reaches the contact portion between the pair of conveying rollers 4 and 5 on the downstream side,
Thereafter, the recording paper 1 is driven by two pairs (two pairs) of the upstream conveying roller pairs 2 and 3 and the downstream conveying roller pairs 4 and 5.
Intermittent paper feed is performed. After the rear end of the recording paper 1 has passed through the upstream conveying roller pairs 2 and 3, the recording paper 1 is conveyed (paper feed) only by the downstream conveying roller pairs 4 and 5.

Even during recording, recording paper (recording medium) 1
When the leading edge of the recording paper (recording medium) 1 is recorded, the recording paper 1 is moved only by the upstream transport roller pairs 2 and 3 until the leading edge of the recording paper (recording medium) 1 reaches the downstream transport roller pairs 4 and 5. The paper is fed (conveyed). Even while the recording paper 1 is being nipped by only the pair of conveying rollers 2 and 3 on the upstream side, the recording paper 1 is kept at the position immediately upstream of the recording means 50 (the nearest position).
7, the leading end of the recording paper 1 is lifted up as shown in FIG.
Of the discharge port surface 81 does not change.

FIG. 4 is a longitudinal sectional view in the front-rear direction of a second embodiment of the ink jet recording apparatus to which the present invention is applied.
FIG. 5 is a vertical cross-sectional view in the left-right direction of the ink jet recording apparatus of FIG. This embodiment is different from the first embodiment in FIGS. 1 and 2 in that the slide member 1 is replaced with the protrusion 13a and the roller 12.
3, a warp-shaped projection 13b is provided at the bottom, and the warped-shaped protrusion 13b is brought into press contact (press-contact) with a newly provided paper pressing member 21.

In the second embodiment, the position regulating means for regulating the distance between the recording means 50 (slide member 13 supporting the same) and the recording medium 1 is provided by the sled-shaped projections 13.
b and the paper pressing member 21. That is, in the present embodiment, the position regulating means is the recording means 50.
(A sled-like projection) 13b connected to the slide member 13 as a support means for supporting the paper member, and a paper pressing member 21 not connected to the slide member 13. The second embodiment of FIGS. 4 and 5 is different from the first embodiment of FIGS. 1 and 2 in the above-described points, but has substantially the same configuration in other respects, and the corresponding portions are the same. Reference numerals are used, and their detailed description is omitted.

In FIGS. 4 and 5, the paper pressing member 21 is formed as a long member having a sectional shape as shown in FIG. 4 and extending in the width direction of the recording medium 1. When the is moving, the drive source (not shown) can move (retreat) in a direction perpendicular to the surface of the recording medium 1 so as to be in non-contact (separation) with the recording medium 1. I have. Further, the paper pressing member 21 is used for the recording medium 1.
Is stopped, the recording medium 1 comes into contact with the recording medium 1, and the recording medium 1 is pressed against the guide member 6.

A warp-like projection 13b of the slide member (supporting means) 13 is in contact with a surface (upper surface shown) of the paper pressing member 21 opposite to the recording medium 1. The contact surface between the protrusion 13b and the paper pressing member 21 is finished to be smooth, and when the carriage 9 moves, the slide member 13 is pressed (pressed) against the paper pressing member 21 by the compression spring 14 and smoothly. It can be moved while always maintaining contact. Therefore, the distance (gap) L between the recording unit (recording head) 50 and the recording medium (recording paper) 1 always keeps a desired value without being affected by the thickness or swelling of the recording medium 1. be able to.

Also, when recording the leading end of the recording paper (recording medium) 1, that is, while the recording paper 1 is nipped only by the pair of conveying rollers 2 and 3 on the upstream side, the recording paper 1 is kept on the recording means. Since the paper holding member 21 is pressed against the guide member 6 at the position closest to 50, the leading end of the recording paper 1 rises as shown in FIG. I will not do it.

As shown in FIG. 4, the position of the paper holding member 21 is located downstream of a tangent line where the pair of rollers (conveying roller pairs) 2 and 3 on the upstream side and the recording medium 1 are in contact with each other.
In addition, it is selected at a position on the upstream side of the upstream end of the ink discharge unit of the recording means 50 (for example, the position of the discharge port closest to the pair of rollers 2 and 3 on the upstream side). Therefore, the paper pressing member 21 does not come into contact with the ink attached to the surface of the recording medium (recording paper) 1 after recording.

According to the embodiment described above, the following effects can be obtained. First, the gap between the recording medium 1 and the recording means 50 can be kept constant at all times with a simple mechanism and without using a complicated control system. Quality can be stabilized. Secondly, since recording is performed with the recording medium 1 held down, even if the recording medium undulates due to ink swelling, recording can be performed without being affected by the ripple. Therefore, it is not necessary to unnecessarily increase the paper gap, and the landing accuracy of ink droplets can be improved, and the quality of a recorded image can be improved. Third, even if the thickness of the recording medium 1 changes, it can be dealt with without performing a thickness detection with a complicated configuration or a switching operation by an operator. Therefore, good operability and stable image quality can be ensured with a low-cost configuration.

Since the position regulating means (the roller 12 and the paper pressing member 21) selects a position where the recording medium 1 comes into contact with an unrecorded area on the recording medium, the position regulating means is ejected onto the recording medium 1. It is possible to prevent the recording medium 1 from being stained without contacting the ink. Further, since the recording means 50 can move linearly and moves the recording medium 1 in a direction substantially orthogonal to the direction, and as a result, performs recording by performing two-dimensional scanning, each movement is linear movement. Therefore, the mechanism can be simplified, which is advantageous for reducing the size of the recording apparatus.

Further, a pair of conveying rollers (two pairs of rollers) arranged at two positions are used as means for conveying the recording medium 1, and the recording means 50 is arranged between these roller pairs. Any one of a mechanism for feeding the recording unit, a mechanism for discharging the recording medium 1 from the recording unit, and a mechanism for feeding the paper during recording can be easily used, and the recording apparatus can be simplified and downsized easily. is there.

The position at which the position regulating means (the roller 12 or the paper pressing means 21) comes into contact with the recording medium 1 is determined by a pair of rollers 2, 3 arranged upstream of the pair of rollers in the recording medium transport direction. The position is selected on the downstream side of the tangent line with which the recording medium 1 contacts and on the upstream side of the upstream end of the ink ejection section of the recording means 50. There is no contact and no contamination of the device and the recording medium occurs. Further, even when recording is performed on the leading end of the recording medium 1, that is, when the recording medium 1 is nipped only by the pair of conveying rollers 2 and 3 on the upstream side, the recording unit 5 is controlled by the roller 12 or the paper pressing member 21.
Since the recording medium 1 is pressed against the guide member 6 at the position closest to 0, the recording medium 1 does not rise and the gap between sheets does not change.

In recent years, the number of ejection ports has tended to increase in order to shorten the recording time, and the length of the recording means 50 in the recording medium transport direction has been increasing. Accordingly, the problem that the distance between the two pairs of transport rollers increases and the leading edge of the recording medium rises is becoming more serious, but the above-described embodiment is a solution to this problem. Further, according to the first embodiment, since the roller 12 as the position regulating means is connected to the slide member 13 as the supporting means, the structure of the apparatus is simple. On the other hand, according to the second embodiment, the position regulating means is divided into the member (projection) 13b which is connected to the support means (slide member) 13 and the member (paper pressing member) 21 which is not connected. A portion that makes rolling contact or frictional contact with the carriage 9 to be moved can be eliminated from the surface of the recording medium 1, and the recording medium 1 is not damaged.

According to the second embodiment, since the member (paper pressing member) 21 not connected to the supporting means of the position regulating means is driven in the contact and retreat direction with respect to the recording medium 1, the moving carriage 9 can be eliminated from the surface of the recording medium 1 in rolling contact or frictional contact with the recording medium 1;
The recording medium 1 is not damaged. Further, since the paper pressing member 21 is retracted while the recording medium 1 is being conveyed, the resistance during conveyance of the recording medium 1 can be reduced. Further, since the position regulating means includes a cylindrical or spherical rotating body, the contact resistance between the moving carriage and the fixed portion can be reduced, and the movement of the carriage becomes smooth.

In the above-described embodiment, the compression spring 1 is used as the urging means for urging the recording means 50 toward the recording medium 1.
Although 4 is used, other means such as an elastic force of another spring, an elastic force of another elastic body, a magnetic force, or gravity may be used as the urging means. The mechanism for holding the recording means 50 so as to be movable in the direction perpendicular to the recording medium 1 is not limited to the slide mechanism as shown in the embodiment. For example, the recording means may rotate around a certain rotation axis. A configuration that is substantially parallel to the recording medium 1 at an appropriate position, a configuration that uses a link, or a configuration that is suspended by an elastic body may be used.

Further, in place of the roller 12 as the position restricting means of the first embodiment, a configuration corresponding to the sled-shaped projection 13b of the second embodiment may be used. Conversely, a roller attached to the slide member 13 may be used instead of the warped projection 13b of the second embodiment. Further, instead of attaching a roller to the slide member, rollers may be arranged at predetermined intervals of the paper pressing member. Instead of the roller 12 as the position regulating means, a spherical body such as a steel ball held rotatably in all directions may be used.

In the second embodiment, the paper holding member 21
Is moved by the drive source so as to retreat from the recording paper 1, but the paper pressing member may be fixed. For example, a method may be used in which the recording paper 1 is brought into contact with the recording paper 1 by the urging force of a slide member fixed in the vicinity of the recording paper 1, or the recording paper 1 may be urged by its own elastic force.

Further, in the above-described embodiment, the case where the paper feeding is performed by intermittent driving has been described. However, the recording paper 1 may be continuously fed at a constant speed. In that case, the slide member 13
However, it is preferable to use a steel ball instead of the roller 12. In the above-described embodiment, the recording paper 1 being recorded is
Although the example in which the recording paper is transported by the transport roller pair has been described, a configuration in which the recording paper is fixed to a flat stage or a cylindrical drum, and the stage or the drum is moved to perform the recording. Further, in the above-described embodiment, an example has been described in which the recording paper 1 and the recording head 50 are moved in directions perpendicular to each other to perform two-dimensional recording. However, only the recording head or only the recording paper is two-dimensionally recorded. A configuration in which recording is performed by moving the recording medium may be employed.

Further, according to the present invention, when the recording means (recording head) is a replaceable head cartridge in which the ink discharging section and the ink storing section are integrated, the ink discharging section and the ink storing section are separately provided, and these are formed into tubes. The present invention can be similarly applied irrespective of the form of the recording means and the ink storage section, such as those connected by the same, and has the same effect.

Further, the present invention is directed to a recording method using a single (single color) recording means, a color recording method using a plurality of recording means using inks of different colors, and a recording method using the same color ink of different shades. The same effect can be obtained regardless of the number or type of recording means, such as in the case of gradation recording by means of recording, or in the case of recording by appropriately combining these, and the same effect can be obtained.

Further, the present invention can be applied to an ink jet recording apparatus using, for example, a recording head using an electromechanical transducer such as a piezo element or the like. This provides excellent effects in an image forming apparatus using a recording head of a discharge type. According to such a method, it is possible to achieve higher density and higher definition of recording.

[0054]

As is apparent from the above description, according to the first aspect of the present invention, in an ink jet recording apparatus which performs recording by discharging ink from a recording means to a recording medium, the recording means is connected to the recording medium. A supporting means for supporting the recording medium so as to approach and separate from the recording medium; an urging means for urging the supporting means in a direction approaching the recording medium; and a distance between the supporting means and the recording medium in contact with the recording medium. And a position regulating means for regulating, so that an extra control system is not required, and a simple structure is used to reduce the gap between the recording means and the recording medium without being affected by swelling or waving of the recording medium. Provided is an ink jet recording apparatus which can always be kept constant, stably improve the landing accuracy of ink droplets, and improve the quality of a recorded image.

According to the second and third aspects of the present invention, in addition to the configuration of the first aspect, the position at which the position regulating means contacts the recording medium is an unrecorded area on the recording medium, or The recording means is movable with respect to the recording medium, and the recording medium is movable in a direction substantially perpendicular to the direction of movement of the recording means.
Since the recording is performed on the recording medium by performing the dimensional scanning, the above-described effect can be obtained more efficiently.

According to the fourth and fifth aspects of the present invention, in addition to the configuration of the third aspect, the conveying means for moving the recording medium has two pairs of rollers arranged at a predetermined distance.
A configuration in which a recording unit is disposed between the two pairs of rollers, or a position where the position regulating unit contacts the recording medium is a pair of the two pairs of rollers disposed on the upstream side in the recording medium conveyance direction. The position is located downstream of the tangent line where the roller contacts the recording medium and upstream of the upstream end of the ink ejection section of the recording means, so that the above effects can be achieved more efficiently.

According to the invention of claims 6 to 9, in addition to the structure of claim 1, the position restricting means is connected to the support means, and the position restricting means is provided with respect to the support means. A structure in which the member which is not connected to the supporting means of the position regulating means has a means capable of contacting and retracting with respect to the recording medium; or Since the restricting means is configured to include a cylindrical or spherical rotating body, the above-described effect can be achieved more efficiently.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view in the front-rear direction of a first embodiment of an ink jet recording apparatus to which the present invention is applied.

FIG. 2 is a schematic longitudinal sectional view of the ink jet recording apparatus of FIG. 1 in the left-right direction.

FIG. 3 is a partial perspective view schematically illustrating a structure of an ink ejection unit of the recording unit in FIG.

FIG. 4 is a schematic longitudinal sectional view in the front-rear direction of a second embodiment of the ink jet recording apparatus to which the present invention is applied.

5 is a schematic longitudinal sectional view of the ink jet recording apparatus of FIG. 4 in the left-right direction.

FIG. 6 is a schematic longitudinal sectional view showing a state during recording of a conventional ink jet recording apparatus.

FIG. 7 is a schematic longitudinal sectional view showing a state immediately after a recording medium is supplied by the ink jet recording apparatus of FIG. 6;

FIG. 8 is a schematic longitudinal sectional view showing another example of the structure of a conventional ink jet recording apparatus.

[Explanation of symbols]

 Reference Signs List 1 recording medium (recording paper) 2 transport roller (upstream side) 3 pinch roller 4 transport roller (downstream side) 5 pinch roller 6 guide member 7 recording means (recording head) 8 ink tank 9 carriage 10 carriage guide 11 carriage guide 12 roller (Position regulating means) 13 Slide member (supporting means) 13a Projection 13b Warped projection 14 Compression spring (biasing means) 21 Paper pressing member 81 Discharge port surface 82 Discharge port 83 Common liquid chamber 84 Liquid path 85 Electrothermal converter L Paper gap

Claims (11)

[Claims] 1. An ink jet recording apparatus which performs recording by discharging ink from a recording unit to a recording medium, wherein the supporting unit supports the recording unit so as to be able to approach and separate from the recording medium, and An ink jet recording apparatus comprising: urging means for urging in a direction approaching a recording medium; and position regulating means for regulating a distance between the supporting means and the recording medium by contacting the recording medium. . 2. The ink jet recording apparatus according to claim 1, wherein the position at which the position regulating means contacts the recording medium is an unrecorded area on the recording medium. 3. The recording means is movable with respect to the recording medium, and the recording medium is movable in a direction substantially orthogonal to a moving direction of the recording means, and as a result, performs two-dimensional scanning. 2. The ink jet recording apparatus according to claim 1, wherein the recording is performed on the recording medium. 4. The apparatus according to claim 1, wherein said conveying means for moving said recording medium has two pairs of rollers arranged at a predetermined distance, and said recording means is arranged between said two pairs of rollers. 4. The inkjet recording apparatus according to 3. 5. A position where the position regulating means contacts the recording medium is located downstream of a tangent line where the recording medium comes into contact with a pair of rollers of the two pairs of rollers arranged upstream in the recording medium transport direction. 5. The ink jet recording apparatus according to claim 4, wherein the ink jet recording unit is located at a position upstream of an upstream end of an ink discharge unit of the recording unit. 6. An ink jet recording apparatus according to claim 1, wherein said position regulating means is connected to said support means. 7. The ink jet recording apparatus according to claim 1, wherein the position regulating unit is divided into a member coupled to the supporting unit and a member not coupled to the supporting unit. 8. The ink jet recording apparatus according to claim 7, wherein a member of the position restricting unit that is not coupled to the supporting unit has a unit that can be retracted in contact with the recording medium. 9. The ink jet recording apparatus according to claim 1, wherein said position regulating means includes a cylindrical or spherical rotating body. 10. An ink jet recording apparatus according to claim 1, wherein said recording means is an ink jet recording means provided with an electrothermal transducer for generating thermal energy used for discharging ink. . 11. An ink jet recording apparatus according to claim 10, wherein said recording means discharges the ink from a discharge port using film boiling generated in the ink by thermal energy generated by the electrothermal transducer. .