JP2000351203A - Ink jet recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress adhesion of an ink mist to a recording medium by transferring while curving the recording medium so that a distance between a recording face and a nearly central part of a liquid discharge port formation face becomes larger than a distance between the recording face and the other part than the central part, and correcting a liquid discharge timing to keep a deviation of hit positions within a predetermined value. SOLUTION: A platen member 26 is formed into a recess shape (curved shape) to make a relative distance to a central part of an ink discharge opening formation face 44a to be larger than a distance to an either end part of a recording head part 44, where a paper 20 is transferred. In a control unit, for controlling a recording operation of the recording head part 44, image data read out with a predetermined timing from a memory part is processed in a predetermined manner by an image process part, a recording operation control data group is supplied to a recording operation control part, and each correction discharge timing signal from a discharge timing-signal correction part is supplied. A discharge timing from each ink discharge opening is corrected in accordance with a relative distance to a recording face of the paper 20.

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 capable of suppressing undesired staining of a predetermined portion of a recording medium.

[0002]

2. Description of the Related Art In an ink jet recording apparatus, generally, a recording medium is, for example, as shown in FIG.
It is arranged to face the ink ejection port forming surface of the recording head in the recording section disposed in the housing which is a substantially closed space.

In FIG. 11, a recording section includes a recording head 1.
The ink cartridge 14 includes the ink cartridge 14 having the 4A and the carriage member 10 to which the ink cartridge 14 is selectively mounted.

The carriage member 10 is reciprocally movable in a direction perpendicular to the paper surface by inserting guide shafts 12A and 12B extending in a direction perpendicular to the paper surface in parallel with each other at a predetermined interval. Carriage member 1
Numeral 0 is connected to a transport belt to which rotational power from a drive motor (not shown) is transmitted. Thereby, when the drive motor is brought into the operating state, the carriage member 1
0 is reciprocated via the conveyor belt.

[0005] The ink cartridge 14 includes an ink tank section for storing predetermined ink and a recording head 14A to which ink is supplied from the ink tank section. The recording head 14A has, for example, a heater as an electric conversion element driven by a drive control signal from a control unit (not shown) corresponding to each ink ejection port. On its lower end surface, an ink ejection port forming surface 14a on which a plurality of ink ejection ports for selectively ejecting ink are arranged and formed is formed. The number of such ink ejection ports tends to increase in response to a demand for high-speed printing, and the drive frequency of the drive control signal also tends to increase.

[0006] Ink ejection port forming surface 1 of recording head 14A
Below 4a, the recording surfaces of the recording medium 2 conveyed intermittently at a predetermined timing are arranged to face each other. The recording medium 2 is nipped and conveyed by conveyance roller units 4A and 4B and conveyance roller units 6A and 6B which are arranged on the upstream side and the downstream side, respectively. Further, the ink ejection port forming surface 14 of the recording head 14A
Below plate a, a platen member 8 for keeping the recording surface of the recording medium 2 flat from below is arranged.

In such a configuration, the recording head 14
A is controlled based on a drive control signal corresponding to data representing an image to be printed. For example, as shown in FIG. Are ejected onto the recording surfaces of the respective recording surfaces to perform a recording operation.

[0008]

When the recording operation is performed by the recording head 14A as described above, as shown in FIG. 12A, the main ink droplet ID and the main ink droplet ID are compared with the ink droplet ID. A small droplet IM flies. Such a droplet IM is called a satellite and causes a floating ink mist. Further, as a cause of the ink mist, as shown in FIG. 12B, a part of each ink ID ′ landed on the recording surface of the recording medium 2 rebounds and scatters in a direction indicated by an arrow, and a small droplet is formed. IM ′, which may be an ink mist. Further, as shown in FIG. 12C, inks of a plurality of ink colors are sequentially supplied from the ink discharge port forming surface 14a of the recording head 14A.
In the case where the ink CI is ejected onto the recording surface of the recording medium 2, when each ink droplet MID of a different ink color lands next to the ink CI that has already landed on the recording surface, part of each ink droplet MID , Scattered in the direction indicated by the arrow
And it may become an ink mist. Such ink mist increases as the number of the ink ejection ports increases and the driving frequency increases.

As described above, a part of the ink mist group including the small droplets IM 'floating near the recording head 14A gradually moves away from the position below the recording head 14A in the direction indicated by the arrow shown in FIG. Along the edge of the recording surface surrounding the recording area.

For example, in the case of a recording medium 2 having a predetermined standard size, as shown in FIG. 14, the ink mist is separated from an area 2R on the recording surface where images, characters, etc. are formed, for example, two points. There is a case where it adheres to the region surrounding the region 2R sandwiched between the chain lines 2A and 2B.
In such a case, especially when the recording surface of the recording medium 2 is white, the adhesion of the ink mist becomes more conspicuous than when the ink mist adheres to the region 2R. Such an ink mist is not so problematic when the recording resolution is less than 360 dpi. However, for example, a condition that the recording resolution is 360 dpi or more, the number of ink ejection ports is 128 in one row, and the driving frequency is 6 kHz. In the case where the recording operation is performed, the amount of ink mist increases, so that there is a problem of ink mist adhering to the region surrounding the region 2R sandwiched between the two-dot chain lines 2A and 2B.

In view of the above problems, the present invention relates to an ink jet recording apparatus capable of suppressing undesired staining of a predetermined portion of a recording medium, wherein an ink mist is used for recording an image or the like on the recording medium. It is an object of the present invention to provide an ink jet recording apparatus capable of suppressing the adhesion of the ink on the periphery of a recorded area in which is formed.

[0012]

In order to achieve the above object, in an ink jet recording apparatus according to the present invention, a liquid discharge port for discharging a liquid used for recording is formed on a recording surface of a recording medium. The recording unit having the liquid ejection port forming surface, and the distance between the recording surface of the recording medium and the substantially central portion of the liquid ejection port forming surface is different from that of the recording medium other than the substantially central portion of the recording surface and the liquid ejection port forming surface And a transport unit that transports the recording medium in a curved manner so as to be larger than the distance between the recording medium and the ejection timing of the liquid from the liquid ejection port of the liquid ejection port forming surface in the recording unit. A discharge timing correction unit that forms and sends a corrected discharge timing signal so as to correct the deviation of the landing position according to the mutual distance between the discharge timing correction unit and the liquid discharge port forming surface; Correction discharge timing Grayed signal, and configured to include a recording operation control unit for controlling the recording operation of the recording unit based on the image data representing the image to be formed on the recording surface of the recording medium.

[0013]

FIG. 1 schematically shows a main part of a first embodiment of an ink jet recording apparatus according to the present invention.

Referring to FIG. 1, the recording section of the ink jet recording apparatus includes an ink cartridge 40 having a recording head section 44 and a carriage member 36 to which the ink cartridge 40 is selectively mounted.

The carriage member 36 includes guide shafts 38A and 38B extending in parallel with each other at a predetermined interval in a direction perpendicular to the paper surface.
By being inserted into the paper b respectively, it is supported so as to be able to reciprocate in a direction perpendicular to the paper surface. Carriage member 3
Numeral 6 is connected to a transport belt (not shown in FIG. 1) to which rotational power from a carriage motor 70 described later is transmitted. The transport belt is wound around a pair of pulleys that are rotatably provided to face each other in the housing of the apparatus. One of the pair of pulleys is connected to an output shaft of a carriage motor 70 described later.
Thus, when the carriage motor 70 is activated, the carriage member 36 is reciprocated a predetermined distance.

The ink cartridge 40 disposed on the mounting portion of the carriage member 36 includes an ink tank section 42 for storing predetermined ink, for example, black ink, and a recording head section for supplying ink from the ink tank section 42. 4
4 is included. As shown in FIG. 2, the recording head unit 44 is, for example, of a bubble jet type, and includes a thin plate-shaped substrate 50 and a top plate member 48 arranged to face the substrate 50. I have.

For example, a substrate 50 made of silicon or the like
The ink flow path 4 is provided between the inner surface of the
4bi (i = 1 to 128) are formed along a direction substantially perpendicular to the moving direction of the carriage member 36. Adjacent ink flow paths 44bi are separated from each other by partition members formed on opposing surfaces of the top plate member 48.

At one end of each ink flow path 44bi,
Ink ejection ports 44ai (i = 1 to 128) are formed,
At the other end of each ink flow path 44bi, a common liquid chamber 46 where the ink flow paths 44bi are joined is formed.
Therefore, the ink ejection port forming surface 44a having a plurality of ink ejection ports 44ai formed along a direction substantially perpendicular to the moving direction of the carriage member 36 is formed flat.

The average distance between the ink discharge ports 44ai is, for example, about 70 (μm) in order to obtain a resolution of 360 dpi, and the distance between the ink discharge ports 44ai is 70 from the center toward the both ends. (Μm). Substrate 5
0, the heater 50ai (i = 1) as an electrothermal converter is provided on the surface facing each ink flow path 44bi.
To 128) are formed. Each heater 50ai is covered with a protective film 50b. Each heater 50ai
The recording head unit 44 is electrically connected to the input / output terminal unit by an electrode wiring network formed on the surface of the substrate 50 by a film forming technique.

The common liquid chamber 46, as shown in FIG.
It communicates with the inside of the ink tank section 42 via the ink supply pipe 46a. The inside of the ink tank section 42 is maintained at a predetermined negative pressure.

As shown in FIG. 1, a paper feeding section 32 in which a sheet 20 as a recording medium to be recorded is loaded and stored, and a paper feeding section 32 Roller units 24A and 24A that intermittently convey and intermittently hold the sheet 20 fed from the printer 20 in cooperation with the recording operation of the recording head unit 44
B and the discharged paper 34 while cooperating and nipping the recorded paper.
Discharge roller units 22A and 22B that discharge paper to
A platen member 26 that is disposed between the paper feed roller units 24A and 24B and the paper discharge roller units 22A and 22B and below the recording head unit 44 and that guides the conveyed paper 20 in a curved manner is disposed. I have.

The paper feed section 32 is provided with a pickup roller 28 for sequentially feeding out the uppermost sheets 20 of the stacked sheets 20 one by one. The pickup roller 28 having a semicircular cross section is fixed to a rotating shaft 30 connected to an output shaft of a drive motor (not shown).

An output shaft of a paper transport motor 72 is connected to one of the paper feed roller units 24A and 24B. Further, the discharge roller units 22A and 22A
B is linked to the rotation of the paper feed roller units 24A and 24B, for example, via a belt group not shown. The paper feed roller unit 24A includes a paper transport motor 7 controlled by a control unit 64 described later.
2 output shafts are connected.

The platen member 26 is, for example, a metal sheet material and is curved downward (concave shape), that is, a predetermined shape so as to surround the carriage member 36 and the ink discharge port forming surface 44a of the recording head unit 44. It is formed as a part of an arc having a radius of curvature.

In the platen member 26, the relative distance at the center of the ink discharge port forming surface 44a is larger than the relative distance between the both ends of the ink discharge port forming surface 44a of the recording head unit 44. It is formed in a concave shape. At this time, the ink ejection port forming surface 4 of the recording head unit 44
One end of each normal line to the curved surface of the platen member 26 facing the surface 4a is gathered near the lower portion of the ink discharge port forming surface 44a. That is, the center of curvature of the curved surface is located on the recording head section 44 side.

The shape of the platen member 26 is not limited to a part of a circular arc, and the sheet 20 can be conveyed.
It may be a part of an elliptical shape that does not involve a sudden change, or a shape that becomes a part of a parabola.

Therefore, when the paper transport motor 72 is activated, the paper 20 fed one by one by the pickup roller 28 is intermittently transported by the paper feed roller units 24A and 24B and the platen member 26 After that, the recorded paper is discharged to the paper discharge unit 34 by the paper discharge roller units 22A and 22B.

In the first embodiment of the ink jet recording apparatus according to the present invention, and in other examples described later, in addition to the above-described configuration, as shown in FIG.
4 are provided.

In FIG. 5, a data group DQ including image data representing an image to be recorded and control data from the host computer 60 is supplied to the control unit 64 through the communication unit 62 every one or several scans. Is done. When the data group DQ is supplied from the host computer 60, the communication unit 62 is set to the reception state, and the communication unit 62 indicates the operation state of each control unit from the control unit 64 and the storage capacity of the memory unit. When the data and the transfer confirmation data are supplied, the transmission state is set to transmit the data to the host computer 60. Although not shown, the control unit 64 is supplied with a detection signal from a temperature sensor for detecting the temperature of the recording head, and a command signal group from a display operation unit for instructing start or stop of a recording operation. You.

The control unit 64 includes a memory unit 64M for storing a data group DQ supplied from the communication unit 62, operation program data for controlling each control unit, and the like.
have.

When the control unit 64 conveys the sheet 20 in accordance with the recording operation of the recording head unit 44, the control unit 64 controls the sheet conveying motor 72 based on a supplied recording operation start command signal to activate the sheet conveying motor 72. A Cpp is formed and supplied to the transport controller 66. The transport controller 66 forms a drive control signal based on the control signal Cpp to rotate the paper transport motor 72 in a predetermined direction by a predetermined angle, and supplies the drive control signal to the paper transport motor 72. Further, the control unit 64 forms a control signal Cpc based on the supplied recording operation start command signal so as to activate the carriage motor 70, and supplies the control signal Cpc to the transport control unit 66. The transport control unit 66 forms a drive control signal to reciprocate the carriage member 36 by a predetermined distance and supplies the drive control signal to the carriage motor 70.

As a result, the carriage member 36 on which the recording head unit 44 is mounted is moved to the guide shafts 12A and 12A.
The paper 20 is reciprocated while being guided and supported by 2B, and the paper 20 is intermittently conveyed below the recording head unit 44 one by one.

The control unit 64 supplies the image data DG read from the memory unit 64M at a predetermined timing to the image processing unit 68 when controlling the recording operation of the recording head unit 44. At that time, the control unit 64 supplies a control signal group Cr including an enable signal and the like to the image processing unit 68.

The image processing section 68 performs predetermined processing based on the supplied image data DG, for example, density conversion processing, binarization processing, and registration adjustment processing according to the ink ejection port arrangement of the recording head section 44. And the like to obtain a recording operation control data group. The recording operation control data group is supplied to the recording operation control unit 78.

The recording operation control unit 78 includes an image processing unit 68
And the corrected ejection timing signals SEO to SE from the ejection timing signal correction unit 76.
N is supplied.

The discharge timing signal correction section 76 includes, for example, a scale section provided along the movement path of the carriage member 36 and a slit provided in the carriage member 36 to synchronize with the movement of the carriage member 36. The detection output signal Se is supplied from an encoder unit 74 including an optical sensor for reading out and outputting a detection output signal.

The ejection timing signal correction section 76 has the configuration shown in FIG.
A, a rectangular wave detection output signal Se is supplied. The ejection timing signal correction unit 76 includes a plurality of delay circuit units 76di (i = 1 to n, where n is an integer) that form the ejection timing signals SE1 to SEN with the rising time of the detection output signal Se delayed by a predetermined period. It is provided corresponding to each ink ejection port.

The delay circuit section 76d1 is, for example, a C
, The rising time point to of the detection output signal Se
, A discharge timing signal SE1 rising at the time point t1 delayed by 1/10 cycle is formed and transmitted.

The delay circuit section 76d2 is provided, for example, as shown in FIG.
, The rising time point to of the detection output signal Se
, A discharge timing signal SE2 rising at time t2 delayed by 2/10 cycle is formed and transmitted.

The delay circuit section 76d3 is provided, for example, in E of FIG.
, The rising time point to of the detection output signal Se
, A discharge timing signal SE3 rising at a time t3 delayed by a period of 5/10 cycle is formed and transmitted.

The ejection timing signal SEO which is the same as the detection output signal Se is, for example, a plurality of inks formed in a substantially central area A on the ink ejection port forming surface 44a of the recording head section 44. The ejection timing signal SE <b> 1 is used for the ink ejection timing of the ejection port, and the ejection timing signal SE <b> 1 is the ink ejection timing of the plurality of ink ejection ports arranged in the region B adjacent to both ends with respect to the plurality of ink ejection ports substantially at the center. Used for

The ejection timing signal SE2 is used, for example, for ink ejection timing of a plurality of ink ejection ports formed in a region C adjacent to the region B on both ends. Further, the ejection timing signal SE3 is
For example, it is used for ink ejection timing of a plurality of ink ejection ports formed in the area D adjacent to both ends of the area C.

Therefore, the timing of ink ejection from each ink ejection port is corrected according to the mutual distance from the ink ejection port forming surface to the recording surface of the paper 20 conveyed.

The recording operation control unit 78 outputs the ejection timing signals SEO to SEN from the ejection timing signal correction unit 76.
A recording operation control pulse signal group is formed and supplied to the recording head unit 44 so that the recording head unit 44 performs a recording operation based on the recording operation control data group from the image processing unit 68 and the recording operation control data group.

As shown in FIG. 4, the recording head unit 44 is reciprocated in a direction substantially perpendicular to the paper surface, and when performing a recording operation on the recording surface 20R of the paper 20, the recording surface 20R The ink mist formed at the time of ink ejection due to the rebound of a part of the ink that has arrived is near a predetermined position below the recording head unit 44 in the direction indicated by the arrow in FIG. Therefore, a relatively large number will be assembled and float. Therefore, recording surface 2
It is possible to suppress the ink mist from adhering to a portion other than the region where the image is formed at 0R.

FIG. 7 schematically shows a main part of a second embodiment of the ink jet recording apparatus according to the present invention.

In the example shown in FIG. 7, in the example shown in FIG. 1, the platen member 26 is formed in a curved shape, but instead, the opposed slope portions 80A and 80A are opposed to each other.
B, and a platen member 80 including a flat surface portion 80F interconnecting the inclined portions 80A and 80B is provided below the recording head portion 82.

In this embodiment, components other than the recording head section 82 and the platen member 80 in the apparatus also include:
Although they are provided in the same manner as in the above-described example, the duplicate description thereof will be omitted.

The recording head 82 forming a part of the ink cartridge is selectively detachable from the carriage member 36. The recording head unit 82 includes the recording head unit 44 described above.
In the same manner as the above, a bubble jet type is used, and only black ink is ejected. Further, the plurality of ink ejection ports provided on the ink ejection port forming surface 82a of the recording head unit 82 correspond to the paper 2
0 are arranged along the carrying direction. The distance between the plurality of ink ejection ports in the area A on the ink ejection port forming surface 82a is set to, for example, about 70.5 (μm). , About 61.1 (μm). As described above, the distance between the ink discharge ports on both sides other than the region A on the ink discharge port forming surface 82a is
The reason why the distance is smaller than the distance between the ink discharge ports in the area A is that when the paper 20 is recorded and then extended along the transport direction, the plurality of ink discharge ports corresponding to the area A This is for the purpose of uniformly recording the portions formed by the ink and the portions formed by the ink from the plurality of ink ejection ports corresponding to the portions other than the region A at equal intervals.

The platen member 80 disposed below the recording head 82 is made of, for example, a thin steel plate. The flat surface portion 80F of the platen member 80 is formed to face the area A of the recording head portion 82. Further, each of the slope portions 80A and 80B intersects a plane including the flat surface portion 80F at an angle of, for example, about 30 degrees.

Accordingly, the distance between the inclined surfaces 80A and 80B and the ink discharge port forming surface 82a is smaller than the flat surface 80a.
It is smaller than the mutual distance between F and the ink discharge port forming surface 82a. Also, the ink discharge port forming surface 82a
One end of each of the normal lines to the slope portions 80A and 80B facing the lower surface is gathered below and below the ink discharge port forming surface 82a.

Under such a configuration, when the sheet 20 is guided and conveyed by the platen member 80 in the direction indicated by the arrow in FIG. 7, and the recording head 82 performs a recording operation on the sheet 20. After the ink from each of the ink ejection ports on the ink ejection port forming surface 82a reaches the recording surface of the paper 20, an ink mist formed at the time of ink ejection due to, for example, a part of the ink bouncing off the ink ejection port forming surface 82a. Since the upstream side and the downstream side of the recording surface 20R of the opposing sheet 20 are inclined, a relatively large amount is gathered and floated near a predetermined position below the recording head section 82. Therefore, it is possible to suppress the ink mist from adhering to a portion of the recording surface other than the region where the image is formed.

In the first and second embodiments described above,
The recording heads 44 and 82 discharge only black ink, but are not limited to such an example.
The recording head unit 82 is, for example, as shown in FIG.
It may have an ink ejection port for ejecting a plurality of different ink colors, respectively.

The recording head 82 ′ shown in FIG. 8 is reciprocated in the direction indicated by the arrow C in FIG. 8, that is, in a direction substantially perpendicular to the direction in which the paper 20 is conveyed. On the left side of the ink ejection port forming surface 82'a, as shown in FIG. 8, ink ejection port arrays 84 for ejecting black ink are arranged in a straight line in a direction substantially perpendicular to the direction indicated by arrow C. Is provided. The ink ejection port arrays 84 are arranged at predetermined mutual average intervals, for example, at intervals of about 40 (μm).
Four are arranged. Also, the ink discharge port forming surface 82a
On the right side, ink ejection opening arrays 86, 88, and 90 for ejecting cyan, magenta, and yellow inks are provided on a straight line, respectively.

The ink ejection port arrays 86, 88, and 90
Is a predetermined mutual average interval, for example, about 40
80 are arranged at intervals of (μm).

Although not shown, the ink tank coupled to the recording head section 82 'has small rooms partitioned therein corresponding to the respective ink ejection port arrays. Each small room stores the ink of each ink color.

FIG. 9 schematically shows a main part of a third embodiment of the ink jet recording apparatus according to the present invention.

In the example shown in FIG.
The ink discharge port forming surface 44a of FIG. 9 is a flat surface, but in FIG.
It is convexly curved toward the lower recording surface so that the mutual distance from the recording surface 2a is uniform.

In FIG. 9, the same components as those in the example shown in FIG. 1 are denoted by the same reference numerals, and the description thereof will not be repeated. Also, a control unit 64 as shown in FIG. 5 is similarly provided.

The recording head unit 92 is of a bubble jet type similarly to the above-described example, and has an ink discharge port forming surface 92 a facing the recording surface of the paper 20. The ink discharge port forming surface 92a has a predetermined radius of curvature, and is formed parallel to the recording surface of the sheet 20 that is curved and conveyed at a predetermined interval.

As shown in FIG. 10, each ink ejection port array is provided on the ink ejection port forming surface 92a, as shown in FIG.
It is formed along a direction indicated by an arrow C of 0, that is, a direction substantially perpendicular to the moving direction of the recording head unit 92.

The ink ejection port array 100 formed at the left end of the ink ejection port forming surface 92a ejects black ink, and is composed of two ink ejection port arrays.
The ink ejection port array 98 formed on the right side of the ink ejection port array 100 ejects cyan ink, and includes two ink ejection port arrays. An ink ejection port array 96 formed on the right of the ink ejection port array 98 ejects magenta ink, and includes two ink ejection port arrays. Further, an ink ejection port array 94 formed on the right side of the ink ejection port array 96 ejects yellow ink, and includes two ink ejection port arrays. Each of the ink ejection port arrays is arranged in parallel with each other.

In each of the ink ejection port arrays 100 to 94,
One ink ejection port array is deviated from the other ink ejection port array by a predetermined amount in a direction substantially orthogonal to the direction indicated by arrow C in FIG. The mutual interval P between adjacent ink ejection ports is
For example, it is set to about 70 (μm). The number of ink ejection ports in each of the ink ejection port arrays 100 to 94 is, for example, 32 in total.

In such a configuration of the recording head unit 92, as in the above-described example, since the recording surface 20R is curved, an ink mist formed by rebounding near a predetermined position below the recording head unit 44 is formed. Will be gathered and float in relatively large numbers. Therefore, it is possible to suppress the ink mist from adhering to a portion other than the area where the image is formed on the recording surface 20R.

The ink discharge port forming surface 92a of the recording head portion 92 is convex toward the lower recording surface so that the interval between the entire recording surface of the paper 20 and the ink discharge port forming surface 92a is uniform. Therefore, there is no need to provide the ejection timing signal correction unit 76 as shown in FIG.
The recording operation control unit 78 can form a drive control pulse signal directly based on the detection output signal Se from the encoder unit 74 directly.

In the above-described example, the recording surface 20R of the sheet 20 is curved by using the platen member.
The paper 20 may be configured to be conveyed while curving the recording surface 20R using only the rigidity of the paper 20 without using the platen member.

[0067]

As is apparent from the above description, according to the ink jet recording apparatus of the present invention, the distance between the recording surface of the recording medium and the substantially central portion of the liquid discharge port forming surface is reduced.
The recording operation is performed by the recording unit while the recording medium is curved and conveyed so as to be larger than the mutual distance between the recording surface of the recording medium and the portion other than the substantially central portion of the liquid ejection port forming surface. In this case, the liquid droplets that have bounced off the recording surface of the recording medium float near the lower portion of the liquid discharge port forming surface, so that an ink mist is generated in the recorded area of the recording medium on which a recorded image or the like is formed. Can be prevented from adhering to the surroundings.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a configuration of a main part of a first embodiment of an ink jet recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing an internal configuration of a recording head in the example shown in FIG.

FIG. 3 is a side view schematically showing the ink cartridge in the example shown in FIG.

FIG. 4 is a diagram provided for explanation of the operation in the example shown in FIG. 1;

FIG. 5 is a block diagram showing a configuration of a control block provided in the first to third embodiments.

FIG. 6 is a waveform diagram of an ejection timing signal used in the example shown in FIG.

FIG. 7 is a sectional view schematically showing a configuration of a main part of a second embodiment of the ink jet recording apparatus according to the present invention.

FIG. 8 is a plan view illustrating an ink ejection port forming surface of a recording head unit used in an example of the inkjet recording apparatus according to the invention.

FIG. 9 is a sectional view schematically showing a configuration of a main part of a third embodiment of the ink jet recording apparatus according to the present invention.

FIG. 10 is a plan view showing an ink ejection port forming surface of the recording head unit in the example shown in FIG.

FIG. 11 is a cross-sectional view schematically showing a configuration of a main part in a conventional device.

FIGS. 12A, 12B, and 12C are diagrams each provided for describing the operation of a conventional device.

FIG. 13 is a diagram provided to explain the operation of a conventional device.

FIG. 14 is a diagram provided for explaining the operation of the conventional device.

[Explanation of symbols]

 Reference Signs List 20 paper 22A, 22B discharge roller unit 24A, 24B paper supply roller unit 26, 80 platen member 36 carriage member 44, 82, 92 recording head unit 44a, 82a, 92a ink discharge port forming surface 64 control unit 72 paper transport motor 76 Discharge timing correction unit

Claims (10)

[Claims] A recording section having a liquid ejection port forming surface on which a liquid ejection port for ejecting a liquid used for recording is formed on a recording surface of a recording medium; a recording surface of the recording medium; and the liquid ejection port. The recording medium is formed such that the distance between the recording medium and the substantially central portion thereof is greater than the distance between the recording surface of the recording medium and the liquid ejection port forming surface other than the substantially central portion. A conveying unit that conveys the recording medium in a curved manner; and a timing of discharging the liquid from the liquid discharge port of the liquid discharge port forming surface in the recording unit, according to a mutual distance between the recording surface of the recording medium and the liquid discharge port forming surface. An ejection timing correction unit that forms and sends a corrected ejection timing signal so as to correct the deviation of the landing position within a predetermined range; a corrected ejection timing signal from the ejection timing correction unit; and recording of the recording medium. Form on surface And a printing operation control unit that controls a printing operation of the printing unit based on image data representing an image to be printed. 2. The ink jet recording apparatus according to claim 1, wherein a center of curvature of a recording surface of the recording medium which is conveyed while being curved by the conveying unit is located on the recording unit side. 3. The ink jet recording apparatus according to claim 1, wherein the liquid ejection port forming surface is a substantially flat surface. 4. A platen member disposed below a substantially central portion of the liquid discharge port forming surface, having a predetermined curved surface on which the recording medium is slidably contacted, and guiding and supporting the recording medium. 2. The ink jet recording apparatus according to claim 1, further comprising: a transfer unit disposed adjacent to the platen member to hold and transfer the recording medium. 5. The liquid discharge port forming surface where a plurality of liquid discharge ports are formed along a direction in which the recording medium is conveyed, wherein the distance between the liquid discharge ports is substantially equal to the liquid discharge port forming surface. 2. The ink jet recording apparatus according to claim 1, wherein the distance is larger than the distance between the liquid ejection ports in the vicinity of both ends along the conveyance direction. 6. The transport section is disposed below the liquid ejection port forming surface, and has a flat surface portion on which the recording medium is slidably contacted, and an extension line extending from the liquid ejection port forming surface which is continuous with the flat surface portion. A platen member having an intersecting slope portion for guiding and supporting the recording medium, and a transfer means arranged adjacent to the platen member for holding and transferring the recording medium. Item 2. An inkjet recording apparatus according to Item 1. 7. A recording section having a curved liquid discharge port forming surface on which a liquid discharge port for discharging a liquid used for recording is formed on a recording surface of a recording medium; A transport unit that bends and transports the recording medium so that the distance between the liquid ejection port forming surface and the liquid ejection port forming surface is uniform; And a recording operation control unit for controlling a recording operation of the unit. 8. A platen member disposed below a substantially central portion of the liquid discharge port forming surface, having a predetermined curved surface with which the recording medium is slidably contacted, and guiding and supporting the recording medium. 8. The inkjet recording apparatus according to claim 7, further comprising: a transfer unit disposed adjacent to the platen member and configured to hold and transfer the recording medium. 9. The ink jet recording apparatus according to claim 7, wherein a center of curvature of a recording surface of the recording medium which is conveyed while being curved by the conveying unit is located on the recording unit side. 10. The ink jet recording apparatus according to claim 1, wherein the recording section has an electrothermal transducer for heating the liquid and discharging the liquid through the liquid discharge port.