JPS6299153A - Liquid injection recording head - Google Patents

Abstract

PURPOSE:To prevent contaminants from scattering during the cleaning of a recording head by allowing the contact surface of a recording head with a plate-like member to smoothly change the of scattering in a relative moving direction of the plate-like member and the recording head. CONSTITUTION:An external cross-section edge obtained by cutting the surface of a recording head 13 in parallel with a plane formed by two directions, i.e. head scan direction 15 and ink droplet discharge direction 16, forms a U-shape on an orifice setting surface which contacts a blade plate 9 during cleaning, thus enabling itself to constitute the recording head 13 using the known various means except a head form. The external cross-section edge of U-shape means a U-shape having an arc curve which continues smoothly centering around an orifice 10 on an orifice setting surface 12 with a linear head side 17 or a U-shape having a linear section near the orifice 10 on the orifice setting surface 12 and a linear head side 17, both linear parts being connected in an arc curve.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid jet recording head used in a liquid jet recording device that performs recording by ejecting a recording liquid as flying droplets, and in particular to a liquid jet recording head that has good cleaning properties. The present invention relates to a liquid jet recording head.

[Prior Art 1] Conventionally, a liquid jet recording method, a so-called inkjet recording method, is known in which recording is performed by ejecting a recording liquid as flying droplets. A liquid jet recording device (inkjet recording device) used in this method generally sprays droplets of a recording liquid (hereinafter referred to as ink) in a direction almost perpendicular to the recording surface of a recording material such as paper or a plastic sheet. An inkjet recording head (hereinafter simply referred to as a recording head) is equipped with an inkjet recording head (hereinafter simply referred to as a recording head) equipped with an ink ejection opening (orifice) for ejecting and ejecting ink droplets to form flying droplets, and Cleaning a head conveying means (for example, a carriage, etc.) for scanning the head in two directions left and right along a straight line 1- which is substantially parallel to the recording surface of the recording material, and at least a part of the orifice of the head. It is equipped with a cleaning means for cleaning.

FIG. 3 is an example of such an inkjet recording device. Incidentally, FIG. 3 shows a schematic plan view of the vicinity of the recording head of the apparatus as viewed from the direction of arrow 5 in FIG. 4, which will be described later.

In FIG. 3, reference numeral 4 denotes a recording head that faces the recording material 14 and generally scans the front surface of the recording material 14 in two directions, right and left. , orifices l are provided in a desired number from one to E depending on the recording density and the like. Of course, the recording head 4 includes an ink droplet ejecting means for ejecting ink droplets from the orifice l, for example, a liquid flow path communicating with the orifice l.
(not shown) and ejection energy generating means (not shown) consisting of a heating element or a piezoelectric element for supplying ejection energy to the ink filled in the liquid flow path. Ink droplets can be ejected from the orifice l. Reference numeral 3 denotes a plate-like member serving as a cleaning means for cleaning the ink droplet ejection side surface of the recording head 4 (that is, the orifice l installation surface), and in this example, it is a blade plate.

FIG. 4 is a schematic perspective view of the recording head of the inkjet recording apparatus in a state where the recording head is mounted on a carriage serving as a head conveying means.

In FIG. 4, numeral 6 is an orifice row schematically showing a desired number of orifices 1 in FIG. 3, and the individual orifices 1 are provided at desired intervals on the row line. 7 is a front plate which is the orifice installation surface of the recording head 4; 8 is a front plate on which the recording head 4 is mounted;
This is a carriage for moving the head almost parallel to the recording surface of the recording material and in two directions, left and right, along the recording surface.

Recording is performed by making ink droplets ejected from the recording head 4 land on the recording material 14 described above using an apparatus configured as shown in FIGS. 3 to 4. During the recording operation, some of the ink may flow out during the ejection of ink droplets, or an ink film may be formed on the recording head 4, particularly on the front plate 7 which is the orifice installation surface of the head 4. This prevents the formation of various types of filth in Tokyo, such as the formation of solidified ink or ink film, or the adhesion of dust floating in the atmosphere to these inks and solids. Not only does this kind of dirt cause stains on the recording material, but if the above dirt is formed near the orifice, the dirt may change the ejection direction of the ink droplets or cause the ink droplets to This can cause phenomena such as the failure to appear, and is a major cause of recording instability.

In order to remove such stains from the recording head, the inkjet recording apparatus is provided with a plate-like member such as a blade plate 3 serving as a head cleaning means, and this plate-like member removes dirt and unnecessary ink. .

The cleaning operation is performed, for example, as follows.

That is, 1. For example, in the configuration shown in FIGS. 3 to 4, by moving the recording pad 4 in the direction of the arrow 11 in FIG. 3 and bringing the blade plate 3 into contact with the front plate 7 of the recording pad 4. For example, it is used to remove dirt on the front plate 7 and clean the recording pad 4, as in the wiper of an automobile. Since cleaning is performed through physical contact between the recording head and the blade plate, the blade plate 3 is generally made of a relatively hard material that does not damage the orifice installation surface and provides sufficient effects. Constructed and also considering cleaning efficiency,
It is usually provided so as to be substantially perpendicular to the scanning direction of the recording head and in contact with the front plate 7 when the recording head moves. Additionally, the cleaning operation can be carried out constantly during the recording operation, but in general, the cleaning operation is performed on the blade plate outside the recording area of the recording head (that is, within the scanning area of the recording head in the area facing the recording material). Usually, the recording head is moved to the blade plate periodically or at any time depending on how dirty the recording head is, and the recording head and the blade plate are brought into contact to perform cleaning.

Of course, depending on the case, a blade plate may be installed within the recording area, and the installation method can be either fixed or movable so that it comes into contact with the recording head only during cleaning. Needless to say, it has been adopted.

In this way, the recording head is cleaned by moving the plate-like member such as the blade plate and the recording head, but the moving speed of the recording head is relatively high for high-speed recording, and cleaning is also difficult. For cleaning to be effective, the recording head and the plate-shaped member must be brought into pressure contact, so that the recording head collides with the plate-shaped member with a relatively large force during cleaning.

In general, the recording head is formed as a rectangular body as shown in FIGS. 3 and 4, so the impact applied to the plate-shaped member at the time of collision between the recording head and the plate-shaped member and at the time of separation of the recording head from the plate-shaped member. becomes particularly large. Then, due to the impact caused by the collision between the recording head and the plate-shaped member, the aforementioned dirt such as ink and solid matter adhering to the front plate of the recording head, or dirt adhering to the plate-shaped member, is scattered. This poses a problem of staining the area around the plate-like member of the inkjet recording device and the recording material.

In order to solve this problem, measures such as installing a head cover 2 as shown in FIGS. 5 and 6 on the recording head to prevent dirt from scattering are also taken. The impact force between the head and the plate member was not alleviated, and a sufficient scattering prevention effect could not be achieved.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and a main object of the present invention is to improve the recording head in the conventional inkjet recording apparatus described above.

Toward a new type of recording that prevents dirt from scattering during cleaning and allows stable recording over a long period of time without ejection failure etc.-I
The objective is to provide a

[Means for Solving the Problems] 'The present invention that achieves the above object includes contacting a plate-like member with at least a part of a surface on which an orifice for ejecting liquid and forming flying droplets is arranged. In a recording head of an inkjet recording apparatus having a cleaning means for moving to clean at least a part of the surface on which the orifice is arranged, a contact surface of the recording head with the plate-shaped member is between the plate-shaped member and the recording head. This recording head is characterized by a smooth shape change in the direction of relative movement of the recording head.

[Example] Hereinafter, the recording head of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an example of an inkjet recording device using an example of the recording head of the present invention, and shows the recording device as described above.
FIG. 3 is a schematic plan view of the vicinity of the recording head seen from the same direction as in the figure.

In FIG. 1, 13 is a recording head, and 10 is an orifice provided in the head 13, which is an ink ejection port. The number of orifices can be one or more as desired, similar to the conventional example. Reference numeral 12 denotes an orifice installation surface of the recording head 13 that comes into contact with the blade plate 9, which is an example of a plate-like member, when cleaning the recording head 13. As a plate member.

In addition to the L blade plate 9, various known types can be widely applied. Reference numeral 15 denotes a key ridge (head conveying means) on a straight line almost parallel to the recording surface of the recording material 14.
(not shown) to the recorder 13 that moves in two directions, left and right.
, and te is generally the ejection direction of ink droplets that are ejected almost perpendicularly to the recording surface of the recording material 14 . Of course, the scanning direction of the recording head is not limited to one example, and it goes without saying that it can be any desired direction.

The feature of the recording head 13 of this example is that the head! As shown in FIG. 1, the outer edge of the cross section of the head 13 obtained by cutting the shape of the head 13 along a plane parallel to a plane formed in two directions, the head scanning direction 15 and the ink droplet ejection direction 1B, is The recording head 13 is formed into a U-shape on the orifice installation surface side that contacts the blade plate 9, and the recording head 13 can be constructed using various known means other than making the head shape as described above. be.

In the recording head of the present invention, the contact surface with a plate-like member such as the blade plate 9 has a smooth shape in the direction of relative movement between the member and the recording head, such as the U-shape shown in FIG. 1 above. It is necessary. Of course, the above U
It goes without saying that, in addition to the letter shape, the object of the present invention can be sufficiently achieved even if the recording head has a shape in which a radius is simply provided at the end of the recording head that contacts the plate-like member.

Here, "-" the outer edge of the cross section forms a U-shape means, for example, that the head side surface 17 is a straight line and the orifice installation surface 12 is connected by a smoothly continuing arc-shaped curve centered on the orifice 10. (Fig. 2), near the orifice 10 on the orifice installation surface 12 and on the head side 1
7 is a straight line, and the U-shape (Fig. 1) is defined by connecting both companies' lines with an arc-shaped curve. In addition, on the orifice installation surface 12.

The curved portion for forming such a U-shape, which may be provided with a protruding portion 18 as shown in FIG. 5, does not necessarily have to be a curved line having a certain curvature such as a semicircle,
It can be a curved line having any curvature that allows the blade plate 9 to smoothly contact and move. Of course, such a curved portion may be symmetrical or asymmetrical with respect to the orifice lO.

By making the shape of the recording head change smoothly, such as the above-mentioned U-shape, when cleaning the recording head using a plate-like member, the orifice installation surface of the recording head to be cleaned can be easily The contact with the plate-shaped member is improved, which improves cleaning performance, and the impact caused by collision or separation between the recording head and the plate-shaped member is alleviated, and it is also possible to prevent dirt from scattering due to the impact. It becomes like this. According to the recording head of the present invention, which improves the leaning performance and prevents the scattering of dirt, it is possible to perform stable recording over a long period of time without problems such as ejection failure or staining of the recording material. It is.

When constructing the recording head of the present invention, the material of the recording head that contacts the plate-shaped member is made of a material with low frictional resistance such as Teflon, or the part is coated with Teflon, so that the recording head and the plate are made of a material that has low frictional resistance. It becomes possible to bring the plate-like member into smoother contact with the plate-like member, and the impact caused by collision or separation between the recording head and the plate-like member is further alleviated, thereby making the present invention more effective.

[Effects of the Invention] As explained above, the present invention provides a novel recording head that can prevent dirt from scattering during recording head cleaning, which was difficult in the past, and can perform stable recording over a long period of time without ejection failure. It is now possible to provide

[Brief explanation of drawings]

FIG. 1 is a schematic plan view of the vicinity of the recording head, illustrating an example of an inkjet recording apparatus using an example of the recording head of the present invention, and FIG. 2 is a schematic plan view of the vicinity of the recording head, illustrating another example of the recording head of the present invention. 3 is a schematic plan view of the vicinity of the recording head for explaining an example of a conventional inkjet recording device, FIG. 4 is a schematic perspective view of the device of FIG. 3, and FIG. 5 is a conventional inkjet recording device. FIG. 6 is a schematic plan view of the vicinity of the recording head for explaining another example of the inkjet recording apparatus, and FIG. 6 is a schematic perspective view of the apparatus shown in FIG. 5. 1.10-m-orifice 4.13-m-recording head 3.9-m-blade plate

Claims (2)

[Claims] (1) Clean at least a portion of the surface on which the orifice is arranged by moving a plate-like member into contact with at least a portion of the surface on which the orifice is arranged for ejecting liquid to form flying droplets. In a liquid jet recording head of a liquid jet recording apparatus having a cleaning means for cleaning, a contact surface of the liquid jet recording head with the plate member has a smooth shape in a direction of relative movement between the plate member and the liquid jet recording head. A liquid jet recording head characterized by changing. (2) The liquid jet recording head according to claim 1, wherein the smooth shape change is U-shaped.