JPH0757890A - Recording device - Google Patents

Abstract

PURPOSE:To provide a recording device in which the turbulence of droplet by the charge of a recording medium is prevented, the range for providing a static eliminating member can be narrower than paper width, and the cost can be reduced by constituting the static eliminating member by a cable. CONSTITUTION:A recording device has a static eliminating member for removing static electricity from a charged recording medium, which is provided on a carriage 1 or a recording head 2. The static eliminating member is earthed through a part of the recording device, and connected to a film cable 3 for supplying signal and power to the recording head, and conductor exposed parts 3a, 3b having sharp top ends are formed on a part of the cable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device.

[0002]

2. Description of the Related Art FIG. 8 (a) is a schematic perspective view showing a conventional static eliminating means, FIG. 8 (b) is a schematic sectional view thereof, and FIG.
8A is a partially enlarged plan view of FIG. 8A, and FIG. 9B is a partially enlarged cross-sectional view of FIG. 8A.

Conventionally, in a recording apparatus for recording on a recording medium, there has been a problem due to charging of the recording medium. The charging of the recording medium is due to the fact that when the recording medium is conveyed by the conveying system of the recording apparatus, static electricity is generated due to friction and the like, and electric charges are accumulated on the recording medium. When the recording medium becomes charged,
In particular, the paper discharge is adversely affected. That is, as shown in FIG. 8B, the discharged recording mediums repel each other due to static electricity (in the direction of the arrow), which disturbs the discharge alignment and obstructs the discharge stacking. Further, among the recording devices, particularly in a recording device which is called an ink jet and which forms an image by flying droplets on a recording medium, as shown in FIG. However, there is a problem in that the flying quality of the recording medium is disturbed by the static electricity of the recording medium and the image quality is impaired.

Conventionally, a so-called charge-eliminating member such as a charge-eliminating brush has been used in order to eliminate the charging of the recording medium. In this method, for example, as shown in FIG. 8A, a static elimination brush 9 is provided in the vicinity of the paper discharge portion over substantially the entire width of the recording medium to remove static electricity charged just before the paper discharge.

[0005]

However, in the above method, since the charge is removed immediately before the paper is discharged, it is effective for the alignment of the discharged paper, but especially for the disturbance of the flight of the droplets in the ink jet recording apparatus. Had no effect because the static electricity had not yet been removed at the droplet flying part.

Therefore, an object of the present invention is to charge a recording medium by providing a charge eliminating member on the carriage on which the recording head is mounted or the recording head itself so that the portion of the recording medium on which recording is performed is erased. Disclosed is to provide a recording head which can prevent the disturbance of the flying of droplets due to the above, can make the range of the static elimination member narrower than the width of the paper, and can reduce the cost by configuring the static elimination member with a cable. .

[0007]

The recording apparatus of the present invention is characterized in that the carriage or the recording head is provided with a discharging means for removing static electricity from the charged recording medium.

The destaticizing means is grounded through a part of the recording apparatus, is connected to a cable for supplying signals and power to the recording head, and the cable is film-shaped. At least one tip forms a conductor exposed portion on a portion of the cable, which is preferably a sharp conductor exposed portion.

It should be noted that the recording head is an ink jet recording head having an electrothermal converter for generating thermal energy for ejecting ink, and the converter causes film boiling in the ink, and the recording head generates bubbles. It is more preferable that the ink is ejected by the pressure change due to the growth.

[0010]

According to one embodiment of the present invention, since the charge removing member is provided on the carriage on which the recording head is mounted or on the recording head itself, droplets are not generated in the portion where the recording is performed on the recording medium, that is, in the ink jet recording apparatus. Since the recording is performed while removing the electrification of the flying and landing portion, it is possible to prevent the recording from being disturbed by the electrification of the recording medium.

Further, according to this method, since the charge eliminating member scans the recording medium together with the carriage to eliminate the charge, it is sufficient that the size of the charge eliminating member is substantially equal to the length of the dot row of the recording head. As described above, it is not necessary to provide the static eliminating member over the width of the paper, and a large cost reduction can be expected.

Further, according to another embodiment of the present invention, since the static elimination member is constituted by a cable for supplying signals and power to the recording head, it is not necessary to separately provide a static elimination member such as a static elimination brush. It is possible to significantly reduce costs.

[0013]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a schematic perspective view of an embodiment of the recording apparatus of the present invention, and FIG. 2 is an exploded perspective view of FIG. As shown in FIGS. 1 and 2, the carriage 1 has a recording head 2
9 is mounted on the carriage shaft 20 shown in FIG. 9A of the above-mentioned conventional example, and is guided by the carriage shaft 20 while scanning in the arrow direction of FIG. 9A for recording. . Here, the recording head 2 is a so-called replaceable head ink cartridge in which the recording head and an ink cartridge that contains ink for forming an image are integrated. Flexible cable (hereinafter abbreviated as flexible) 3
Supplies a recording signal and power to the head 2. The flexible member 3 is provided with a conductor exposed portion 3a that comes into contact with the contact portion of the recording head 2 to establish electrical conduction. The carriage 1 is provided with a support portion 1a for supporting the conductor exposed portion 3a of the flexure 3, and the conductor exposed portion 3a of the flexure 3 is fixed at a position in contact with the contact portion of the recording head 2.

The nozzle 2a of the recording head 2 ejects an ink droplet. When the head 2 is attached to the carriage 1, the oblong hole 2b allows the upper surface of the flexible support portion 1a of the carriage 1 to be seen through the oblong hole 2b so that the head 2 is
It can be confirmed that it is securely attached to.

As the charge eliminating member 5, a so-called charge eliminating brush is used in this embodiment. The static elimination brush 5 is configured integrally with the holder 4, and the holder 4 uses a conductive member such as sheet metal. The static elimination brush 5 is fixed to the carriage 1 together with the holder 4 with screws or the like. At this time, the flexure 3 is already set on the carriage 1, but the flexure 3 is also extended to a position below the holder 4. When the holder 4 is screwed to the carriage 1, the conductor exposed portion 3b provided on the flexible cable 3 comes into contact with the holder 4 and, as a result, the static elimination brush 5 and the flexible cable 3 are electrically connected. Here, the conductor exposed portion 3b is a ground pattern of the conductor pattern of the flexure 3, that is, the static elimination brush 5 is grounded through the flexure 3 as a medium.

When the recording head 2 is attached to the carriage 1 in this state, the form shown in FIG. 1 is obtained. In FIG. 9A, the carriage 1 and the head 2 perform recording while moving from the left direction to the right direction in the figure. The positional relationship between the nozzle 2a and the static elimination brush 5 in FIG. 1 is that the static elimination brush 5 is located on the right side of the nozzle 2a from the viewpoint of FIG. 9 (a). Carriage 1
Since recording is performed while moving from left to right, the static elimination brush 5 scans the surface of the recording medium 11 on which the ink has landed immediately before the ink is ejected from the nozzle 2a. Here, when the surface of the recording medium 11 is charged, the charges on the surface of the recording medium are discharged to the respective tips of the charge eliminating brushes to eliminate the charge on the recording medium. Therefore, at the time when the ink is ejected from the head 2, the surface of the recording medium has been neutralized,
It is possible to obtain a high-quality image without disturbing the ink ejection.

Further, as shown in FIG. 8A of the conventional example, even if the static elimination brush is not provided over the full width of the recording medium, the static elimination brush scans the surface of the recording medium as the carriage scans. Since it functions at least as long as the height of the nozzle 2a, the cost is remarkably reduced as compared with the conventional method. Needless to say, the static elimination brush according to the present embodiment is not only effective against disturbance of ink ejection,
Also effective for paper discharge.

Next, the second and third embodiments will be described.

FIGS. 3A and 3B are schematic perspective views showing parts of the second and third embodiments, respectively.

The second embodiment shown in FIG. 3A is a holder 4
Is formed in a U shape, and the static elimination brush 5 is provided on both sides of the nozzle 2a.
a and 5b are generated. The first embodiment is particularly effective for a printing apparatus that prints only when the carriage scans from left to right, such as an image printer. However, the second embodiment also applies to a printing apparatus that prints in both directions by the carriage. There is a merit that the charge removal of the recording medium can be performed in front of the ink landing, and since the two charge removal brushes are provided, the charge removal effect is further improved.

In the third embodiment shown in FIG. 3B, a static elimination brush is provided on three sides of the U-shaped holder 4 in comparison with the second embodiment. With such a structure, the following effects are further produced. That is, by providing a static eliminator brush having a certain width in the width direction of the recording medium, the carriage is moved to the center of the recording medium, for example, even when the carriage does not scan and only the recording medium is conveyed, that is, the continuous paper feed state. When the paper feed is performed after the charging, the charge removal brush 5b can remove the charge of the recording medium during the paper feed, and the problem of the paper discharge property can be reduced.

Next, the fourth, fifth and sixth embodiments will be described.

FIGS. 4A, 4B and 4C are schematic perspective views showing parts of the fourth, fifth and sixth embodiments, respectively.

In the fourth embodiment shown in FIG. 4 (a),
The static eliminator 6 has a serrated portion of a thin metal plate (for example, a stainless steel plate) facing the recording medium, and its tip is relatively sharp. With such a shape, discharge is generated at the notched tip, and the same effect as that of the method using the charge eliminating brush of the first embodiment can be obtained.
In this method, an inexpensive metal plate is used instead of the relatively expensive static elimination brush, so that the cost can be further reduced.

A fifth embodiment shown in FIG. 4B and FIG.
The sixth embodiment shown in (b) is an arrangement in which the jagged arrangement of the fourth embodiment is increased to two sides and three sides of the U-shaped holder 4, respectively. The effects of the fifth and sixth embodiments on the fourth embodiment are similar to the above-described effects of the second and third embodiments on the first embodiment.

Next, a seventh embodiment will be described.

FIG. 5A is a schematic perspective view of the seventh embodiment, and FIG. 5B is a schematic perspective view showing the charge eliminating member of FIG.

In this embodiment, the charge removing member is provided on the head 2 which is removable from the carriage. The charge removing member 7 uses a plate member that forms the nozzle 2 a of the head 2. The plate member is provided with the above-mentioned notched portions on the left and right sides of the nozzle to serve as the static elimination member 7. The charge removing member 7 is the head 2
Is connected to the ground pattern of the head inside and is grounded by the flexible cable 3. Even with such a configuration,
The same effects as those of the fifth embodiment can be obtained, and since the nozzle constituent member and the static elimination member are also used, the number of parts does not increase and the cost can be minimized.

Next, an eighth embodiment will be described.

FIG. 6 (a) is a schematic perspective view of the eighth embodiment, FIG. 6 (b) is a side view showing the tip portion of the flexible cable of FIG. 6 (a), and FIG. 7 is an exploded view of FIG. 6 (a). It is a perspective view.

In FIG. 7, the flexible cable 3 has two exposed conductor portions 3c ₁ and 3c ₂ . Both parts 3c ₁ and 3c ₂ are formed by forming a part of the flexure 3 in a serrated shape. As shown in FIG. 6B, the tip of the notch has a conductor exposed portion, and the tip is relatively sharp. The conductor exposed portions 3c ₁ and 3c _{2 form} a ground pattern of the flexible cable 3. With such a shape, the flexure 3 can obtain the same effect as the notched shape of the metal plate in the fifth embodiment of FIG. 4B or the seventh embodiment of FIG. 5A. In FIG. 7, the flexible holding member 1d is shown. Similarly to the previous embodiment, two notched portions are provided on both sides of the nozzle 2a of the head 2 in order to position the static elimination portion. 3c ₂ is a front hole 2 of the head 2 when the head 2 is attached to the carriage 1.
It faces the recording medium through c. According to this structure, the static eliminating member can also be used as the flexible member, and thus a great cost merit can be enjoyed.

Next, the above-mentioned ink jet recording apparatus using an ink jet recording head of an ink jet recording system for ejecting ink from an ejection port to perform recording by utilizing thermal energy generated by an electrothermal converter as recording energy. Will be described in more detail.

The typical structure and principle thereof are described in, for example, US Pat. No. 4,723,129 and US Pat.
What is done using the basic principles disclosed in 740,796 is preferred.

This system is applicable to both the so-called on-demand type and continuous type, but in particular,
In the case of the on-demand type, the electrothermal converter arranged corresponding to the sheet or the liquid path holding the recording liquid (ink) corresponds to the recording information and causes nucleate boiling in the recording liquid. By applying at least one drive signal that gives a rapid temperature rise exceeding the above, thermal energy is generated in the electrothermal converter, and the recording liquid near the heat-acting surface of the recording head is film-boiling. As a result, bubbles can be formed in the recording liquid in a one-to-one correspondence with this drive signal, which is effective.

The recording liquid is discharged into the atmosphere by the acting force generated in the process of growth and contraction of the bubbles to form at least one droplet.

It is more preferable to make the driving signal into a pulse shape because the growth and contraction of the bubbles are immediately and appropriately performed, so that the ejection of the recording liquid having an excellent responsiveness can be achieved. As this pulse-shaped drive signal, there is US Pat. No. 4,463,3.
Suitable are those described in U.S. Pat. No. 59, No. 4,345,262.

If the conditions described in US Pat. No. 4,313,124 relating to the rate of temperature rise on the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications, The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose configurations in which a heat acting portion is arranged in a bending region. Is.

Further, by using a full line type recording head having a length corresponding to the maximum width of the recording medium which can be recorded by the recording apparatus or a combination of a plurality of recording heads as disclosed in the above-mentioned specification, the length can be increased. The structure described above may be satisfied, or the structure may be one recording head integrally formed, but in any case, the present invention can more effectively exhibit the above-described effects.

In addition, by being mounted on the apparatus main body, an exchangeable chip type recording head or an ink supply tank capable of electrically connecting with the apparatus main body and supplying ink from the apparatus main body can be used for recording. The present invention is also effective when a cartridge-type recording head provided integrally with the head itself is used.

Further, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc., which are provided as a configuration of the recording apparatus of the present invention, because the effects of the present invention can be further stabilized. .

Specific examples thereof include capping means for the recording head, cleaning means, pressurization or suction means, electrothermal converters or heating elements other than these, or preheating means by a combination thereof. It is also effective to perform stable recording by adding a mark or performing a preliminary discharge mode in which preliminary discharge different from recording is performed. A plurality of them may be provided.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. Alternatively, the present invention is extremely effective for an apparatus provided with at least one of full colors by color mixing.

Furthermore, in the above-described embodiments of the present invention, the ink is described as a liquid, but even if the ink solidifies at room temperature or below, the ink will become liquid or soft when a recording signal is applied. Anything is fine.

In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

[0047]

According to the present invention, the carriage on which the recording head is mounted or the charge eliminating member is provided on the head. Therefore, the portion where the recording is performed on the recording medium, that is, the portion where the droplets fly and land in the ink jet recording apparatus. Since the recording is performed while removing the electrostatic charge, it is possible to prevent the recording from being disturbed by the charging of the recording medium.

Further, according to this method, since the charge eliminating member scans the recording medium together with the carriage to eliminate the charge, it is sufficient that the size of the charge eliminating member is substantially equal to the length of the dot row of the recording head. As described above, it is not necessary to provide the static eliminating member over the width of the paper, and a large cost reduction can be expected.

Further, according to another embodiment of the present invention, since the static elimination member is composed of a cable for supplying signals and power to the recording head, it is not necessary to separately provide a static elimination member such as a static elimination brush. It is possible to significantly reduce costs.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of a recording apparatus of the present invention.

FIG. 2 is an exploded perspective view of FIG.

3 (a) and 3 (b) are schematic perspective views showing parts of the second and third embodiments, respectively.

4 (a), (b) and (c) are schematic perspective views showing parts of the fourth, fifth and sixth embodiments, respectively.

5A is a schematic perspective view of a seventh embodiment, and FIG.
[Fig. 4] is a schematic perspective view showing the static elimination member of (a).

FIG. 6A is a schematic perspective view of an eighth embodiment, and FIG. 6B is a side view showing a tip end portion of the flexible cable of FIG.

FIG. 7 is an exploded perspective view of FIG. 6 (a).

FIG. 8A is a schematic perspective view showing a conventional example, and FIG.
FIG. 4 is a schematic sectional view thereof.

FIG. 9A is a partially enlarged plan view showing a conventional example, and FIG.
FIG. 7 is a partially enlarged cross-sectional view showing a conventional example.

[Explanation of symbols]

1 Carriage 1a Flexible Support 1b Carriage Bearing 1d Flexible Holding Member 2 Recording Head 2a Nozzle 2b Slot 2c Front Hole 3 Flexible Cable (Flex) 3a, 3c, 3c ₁ , 3c ₂ Conductor Exposed 3b Conductor Exposed (Grand Pattern) 4 Holder 4a Screws 5, 5a, 5b, 5c, 9 Static eliminator (static eliminator brush) 6, 6a, 6b, 6c, 7 Static eliminator (static eliminator) 10 Case 11 Recording medium 12 Paper ejection guide 13 Paper guide 14a, 14b Pinch Roller 15 Platen 16 Paper ejection roller 17 Spur 18 Paper stacker 19 Paper retainer plate 20 Carriage shaft

Claims (7)

[Claims] 1. In a serial recording apparatus for performing recording by scanning a carriage carrying a recording head, static elimination means for removing static electricity from a charged recording medium is provided on the carriage or the recording head. Recording device. 2. The recording apparatus according to claim 1, wherein the charge eliminating unit is grounded via a part of the recording apparatus. 3. The static elimination means is connected to a cable for supplying signals and power to the recording head.
Or the recording device according to 2. 4. The recording apparatus according to claim 3, wherein the cable is in the form of a film, and at least one tip of the cable forms a conductor exposed portion having a sharp edge. 5. The recording apparatus according to claim 4, wherein the exposed conductor portion is a ground pattern of the cable. 6. The recording apparatus according to claim 1, wherein the recording head is an inkjet recording head including an electrothermal converter for generating thermal energy for ejecting ink. 7. The electrothermal converter generates thermal energy that causes film boiling in the ink, and the recording head is
The recording apparatus according to claim 6, wherein the ink is ejected from the ejection port by a pressure change caused by the growth of bubbles.