JPH02198847A - Liquid injection recorder - Google Patents

Abstract

PURPOSE:To prevent a wrinkle generation phenomenon and the spotting of recording paper by ink adhering on an orifice surface by providing a means detecting the adhesion of a liquid onto the orifice surface of a recording head. CONSTITUTION:The switch of a current detecting circuit 50 is turned ON, and conductive states among the ink liquids of nozzle sections 34 and pattern electrodes 41, 42 are monitored at all times. When the adhesion of a liquid onto the orifice surface of a recording head is generated by the fog-shaped droplets of discharge ink, steam, etc. or dew condensation, etc., one part of the adhering liquid crosses over even the section 41 or 43, to which the pattern electrode is not installed, thus bringing sections among the ink liquids of the nozzle sections 34 and the pattern electrodes 41, 42 to a conductive state, then detecting the state by a galvanometer. Accordingly, recording is interrupted by a control circuit 19, information is conserved in a memory, and recording paper is discharged while reprinting onto an operation panel is made to inform to a user.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid jet recording device.

[Conventional technology and its issues]

2. Description of the Related Art Liquid jet recording apparatuses (inkjet recording apparatuses) that record information such as characters and images by discharging recording liquid from a recording head onto a recording material are widely known.

Paper or plastic sheets are mainly used as the recording material for this type of device, and it has the advantages of low operating noise and simple and inexpensive basic mechanical structure compared to other recording methods. It is used in various fields as a recording/output device in combiators, word processors, etc.

Among liquid jet recording devices, a line head is used as the recording head, with the number of nozzles corresponding to the width of the recording paper, and multiple recording heads are used, and the recording paper is prepared using methods such as electrostatic attraction. Books held and conveyed on a belt or the like have the advantage of being capable of high-speed color recording.

However, in these liquid jet recording devices, the ink ejection from the nozzles is affected by the adhesion of liquid such as atomized droplets of ejected ink and water vapor to the orifice surface of the recording head due to K during printing and recording. A so-called streak phenomenon occurs in which the position becomes incorrect.

In the worst case, the ink cannot be ejected, and there is also the drawback that the ink adhering to the orifice surface stains the recording paper, which occurs randomly during printing.

An object of the present invention is to prevent such drawbacks and thereby provide a liquid jet recording device with high print quality and reliability.

[Means to solve the problem]

In order to achieve the above object, a liquid jet recording apparatus that performs recording by ejecting recording liquid from a recording head onto a recording material includes means for detecting adhesion of liquid to an orifice surface of the recording head. A liquid jet recording device is provided.

〔Example〕

Hereinafter, an embodiment of the single-shot FJA will be described in detail with reference to the drawings.

FIG. 2 is a perspective view of the entire apparatus according to this embodiment.

Here, reference numeral 1 denotes a recording head, which has 3,456 nozzles arranged at an interval of 16 dots/space on the bottom surface of the figure, and records 216-width lines sequentially. The recording head 1 is compatible with four colors of ink: black, cyan, magenta, and yellow, and has a length of 1 m and 1 m, respectively.

Four lines, lc and ld, are provided.

FIG. 1 is a perspective view of the recording head, 31 is a head base made by Al (Al), 32 is a silicon substrate with a heating element arranged at the nozzle 34, 33 is a common ink chamber 35 and a nozzle 3.
The glass cover 36 that constitutes 4 is the driver of the heating element.
Reference numeral 37 is an ink discharge chain that discharges ink supplied from the ink supply chain 5 to the common liquid 1135 to an ink tank. 40 is the orifice surface. The recording head according to this embodiment has the advantage that a glass cover 33 in which a common ink chamber 35 and a nozzle groove 34 are carved can be covered over a silicon substrate 32 on which a heating element is arranged in a nozzle part 34.
This forms a nozzle row 34.

FIG. 1(b) is a front view of the Oriais surface 40. On the orifice surface of the glass cover 33, a turn electrode 41 is provided by a predetermined width from the surface to be bonded to the silicon substrate 32.
is provided by photoetching, vapor deposition, printing, etc. However, the pattern electrode 41 is not provided in the constant @O portion 43 around the nozzle hole. silicon substrate 32
Similarly, on the orifice surface, a pattern electrode 42 is provided by photo-etching, vapor deposition, printing, etc. over a predetermined width from the surface to be joined to the glass cover 33. In the part facing the nozzle part 34, the pattern electrode 42 is not provided in a part 44 having a constant width from the bonding surface. Therefore, when the silicon substrate 32 and the glass cover 33 are bonded, the 0-order, /4-turn electrodes 41 and 42 are provided with a portion where no pattern electrode of a predetermined width exists around the entire nozzle hole. , a circuit in which a switch and a galvanometer are connected in series (not shown) (hereinafter referred to as a galvanometer circuit)
The other end of the circuit is connected to the nozzle part 34.
The inner lining of the common liquid chamber 35 is in a conductive state with the ink liquid guided to the common liquid chamber 35. Therefore, when the switch is turned on and the ink liquid in the nozzle section 34 and the arm turn electrodes 41, 42 are brought into conduction, a current flows through the galvanometer. The galvanometer circuit 50 is connected to the control circuit 19, and controls such as turning on and off the switch of the galvanometer circuit and stopping recording after a conductive state is detected are performed.

Next, each recording head is held by a holder 2 so that the nozzle spacing in the recording paper conveyance direction is constant. A head unit composed of four recording heads and a holder can be moved up and down by a head moving means 24 (not shown).

Reference numeral 3 designates a cap that is attached to the oriice surface 40 forming the nozzle of the recording head when not recording.

Figure 3 (The figure shows the case where the recording head r1 and the cap 3 are arranged on the same straight line) K As shown, the character f
3 has a striped ink absorbing member 29 inside,
It is configured to receive idle ejection of ink from the print head. Furthermore, a nozzle presser rubber 30 that covers the length of the nozzle row is arranged at the upper end of the cap.

The cap 3 is moved from a cap mover RK (not shown) by
It is possible to move in the direction.

4 is an ink tank corresponding to each recording head, and ink is guided to the recording head via an ink supply tube 5. Ink is supplied using capillary action in the nozzles of the recording head, and the water head of the ink in each ink tank is set a certain distance υ lower than the nozzle surface. 38 is an ink circulation pump that supplies ink into the head under pressure. In addition, 3
7 is an ink return chain, and the ink supplied into the head under pressure is returned to the ink tank 4 through an ink return tube 37.

6 is a seamless belt for conveying the recording paper, and has a high resistance layer (about 100 μm thick) on its surface with a thickness of about 50 μm, and the inner surface is grounded by an idle roller.
The surface is charged to 1500V by charging 612&. The recording paper 27 is injected with a negative charge by the charger 12b and is conveyed by being electrostatically attracted to the belt surface. The belt 6 is rotated by a motor 8 connected to a belt drive roller 7 in a direction to move the recording paper 27 in the X direction. 9#'i Idle roller for pulling the belt 10 is a tension roller that gives a constant tension to the belt. Reference numeral 11 denotes a pinch roller 2- which presses the recording paper against the belt before and after the charger to strengthen suction, and the pinch roller 11m and the belt in that part catch the fed recording paper and loop it inside the guide 13. It also has the function of improving the orthogonality of the leading edge of the recording paper with the X direction.

The recording paper 27 is transferred from the cassette 26 to the paper feed roller 16.
Ninety-one sheets are fed out at a time, pinched by a conveyance roller 14 and a pinch roller 15, and guided to the above-mentioned reso roller corresponding portion 11m.

Paper dust and the like on the belt 6 is removed by the IJ-ning unit 17. 1B is a paper discharge tray on which recorded recording paper is stacked.

Next, the operation of the liquid ejecting device configured in this manner will be described.

4 to 99 are side views of the head unit and the vicinity of the cap. FIG. 4 shows a state in which the power is OFF, and the orifice surface is covered with a cap 3 to prevent ink from evaporating from the nozzle tip.

When the power is turned on from this state, first the switch of the galvanometer circuit 50 is turned on.

Next, the head unit is lifted by the head moving means for about one song (Figure i5). If there is a circulation signal in this state, the cap unit is moved by the cap moving means 25.
When the head is moved in the opposite direction to the X direction by the distance shown in FIG. 3 (FIG. 6), then the head is moved down (FIG. 7), and the ink circulation pump 38 is activated to perform recirculation of the ink.
The head unit will move up (Fig. 6), and the cap unit will return to its original position (Fig. 5). Note that air bubbles and the like inside the ink supply tube 5 and the recording head are removed by the ink circulation.

Next, if there is a blank ejection signal, all nozzles are blanked a predetermined number of times. Note that this is normally performed when the power is turned on or when about 100 sheets have been recorded with continuous paper feeding, but if recording error 2 etc. occurs, the user can input a signal by operating the button. It is structured like this.

Next, the cap unit is moved to
The head is moved in the opposite direction and placed in a position where the cap fits between each head (FIG. 8).

Then, the head unit is set downward and the nozzle tip is set at a distance of about 10 mm from the belt surface, that is, at the recording position (Figure 39).

Next, the paper feed motor is turned on, one recording paper in the cassette 26 is picked up by the paper feed roller 16, and the guide 13
and is sandwiched between a conveyance roller 14 and a pinch roller 15. The passage of the leading edge of the recording paper is detected by a photo sensor immediately before the registration area, and the paper feed motor is turned off a predetermined time after the leading edge reaches the registration area.

The excess recording paper fed at this time forms a loop within the space of the chevron guide 13, and the IIXK leading edge of the recording paper follows the registration portion, ensuring orthogonality with the transport direction.

Next, the belt motor 8 and the charger 12 are turned on, and the recording paper 1 is pressed against the belt 6 by the pinch roller 111, and the belt 11! It is guided between the vessels 12b. belt#"
i. The surface of the charger 12 is charged to about 1500V by the breath, and a minus charge is injected into the recording paper by the charger i2b, and due to the electrostatic force with the glass charge on the belt surface, the recording paper is It is attracted to the belt. In addition, the charger 12b
The pressure of the pinch roller after passing makes the suction more reliable. The feed of the recording paper is counted in synchronization with the activation of the belt motor, and each color is recorded from the time the leading edge of the recording paper reaches its respective recording head.

Here, since the switch of the galvanometer circuit 50 is turned on, the ink liquid in the nozzle section 34 and the pattern electrode 41 .
42 is monitored to see if it becomes conductive. Therefore, if liquid adheres to the orifice surface of the recording spatula P due to mist droplets of ejected ink, water vapor, etc., or dew condensation, a portion of the adhered liquid will be transferred to areas where pattern electrodes are not applied. In order to cross 41 and 1t43,
This causes the ink liquid in the nozzle portion 34 and the pattern electrode 41 to
．． 42, the galvanometer detects this. Then, in this embodiment, the control circuit 19 interrupts the continuous recording, stores the information on the printer, ejects the recording paper, and prompts the user to reprint on the operating spring. By reversing the ink supply motor to the recording head and applying negative pressure to the common liquid chamber that does not exceed the capillary force of the υ nozzle, the ink on the oriice surface is sucked out and then stored in the memory. Reprint the information using the same steps as above.

When the galvanometer does not detect a conductive state, or when a conductive state is detected and reprinting is performed after absorbing the ink on the oriice surface, the recording paper on which recording has been completed is located at the belt drive roller 7. The paper is separated from the belt by the curvature at , and is discharged to the paper discharge tray 18 . After paper ejection is completed, the belt motor 8 is turned off 1,, the charger 12
Also turns off.

If the next recording is not performed, the head unit will rise (Fig. 8) and the cap unit will be set (Fig. 8).
(Fig. 5), the bottom of the head unit is attached to the cap unit (Fig. 4), and the power is turned off.

In addition, when recording the next page, the presence or absence of a dry ejection signal is detected, and if the signal is present, head unit up (Fig. 8), cap unit set (Fig. 5), dry ejection, cap After the unit is retracted (Fig. 8) and the head unit is lowered to the recording position (Fig. 9), or immediately if there is no signal, the paper feed motor is turned ON.
A recording sequence similar to that described above is repeated.

Incidentally, a 70-chart of the above operation is shown in Fig. 1θ.

In this embodiment, a galvanometric circuit detects small droplets of ejected ink, water vapor, dew condensation, etc. adhering to the orifice surface of the recording head, and then the recording is interrupted and the ink supply motor is rotated in the reverse direction. Since the ink on the surface is absorbed, droplets and water vapor adhering to the orifice surface are removed, thereby preventing the smearing phenomenon and staining the recording paper.

, 9. Inability to eject the ink liquid due to mist-like droplets, water vapor, condensation, etc. of the ejected ink adhering to the orifice surface,
However, recording continues despite this, and it is also possible to prevent an incomplete image from being formed without ink being ejected from a specific nozzle.

(9) In this embodiment, since the galvanometer circuit 50 is turned on when the device is powered on, even if the oriice surface becomes dirty during an operation other than printing and recording, it can be immediately detected and the dirt can be absorbed. By doing so, the throughput of the device can be further improved. Note that the galvanometer circuit 50 can also be switched on at the start of print recording.

In the above embodiment, as a means for removing dirt on the orifice surface, the ink supply motor is reversed to suck ink from the orifice surface into the nozzle, but various other means can be considered for removing dirt.

For example, a wiping means for wiping the ink liquid on the orifice surface with a cloth, sponge, etc. is provided in the device, and when it is detected that ink has adhered to the orifice surface, the orifice surface is wiped with this wiping means. is also possible.

Furthermore, in the above embodiment, the conduction state between the ink liquid in the nozzle section 34 and the nozzle turn electrodes 43, 42 is detected, but a plurality of electrodes are arranged on the orimeter surface of the recording head, and these electrodes are connected to each other as described above. The galvanometer circuit may be connected to both ends of the galvanometer circuit, so that the galvanometer circuit becomes conductive when ink or the like straddles the plurality of electrodes.

Further, as a means for detecting ink adhesion on the orifice surface, a detection means such as an optical detection means may be used. for example,
It is also possible to irradiate the orifice surface with light, detect the reflected light with an optical sensor such as a photodiode, and detect the adhesion state of the yelp on the geo-orifice surface based on the change in the reflected light.

Further, although the above embodiment is a line head type liquid jet recording device, the present invention can also be applied to a serial type liquid jet recording device in which recording is performed by moving the recording head back and forth in the width direction of the recording material. be.

Furthermore, although the above embodiment uses a cap provided on the cap as a means for blocking the nozzle during ink circulation, other independent members may be used, or the material may be made of soft glass or other materials.

Furthermore, although the above embodiment is a recording device that attracts and conveys written paper on a belt by electrostatic adsorption, the above embodiment is an example to which the present invention is applied. The present invention can be applied to other types of liquid jet recording devices, such as a recording device that uses suction to convey the recording paper onto a belt, a recording device that conveys the recording paper using a drum, and the like.

〔Effect of the invention〕

Since the liquid jet recording device Rii according to the present invention has means for detecting the adhesion of liquid to the oriice surface of the recording head,
If liquid adheres to the orifice surface, it is immediately detected.
If necessary, removing the liquid by an appropriate means may affect the ejection of ink from the nozzle and cause the recording position to be distorted, which is the so-called streak phenomenon, or the printing paper may be stained by the ink adhering to the oriice surface. It is possible to eliminate defects that randomly occur during recording, and provides a device with high printing quality and reliability.

[Brief explanation of the drawing]

FIGS. 1 to 10 are explanatory diagrams showing one embodiment of the present invention, of which FIG. g1(a) is a perspective view of the recording head;
Figure (b) is a front view of the oriice surface of the recording head, Figure 2 is a perspective view of the entire device, Figure 3 is a sectional view of the cap in Figure 2, and Figures 4 to 9 are FIG. 10 is a side view for explaining the operations of the head unit and cap in the figure, and FIG. 10 is an operation flowchart of FIG. 2. 1 Todoroki, 1b, le, ld...recording head, 27...
Recording paper, 34... Nozzle section, 3B... Ink circulation pump, 40... Orifice surface, 41.42... Nomaturn electrode. Agent Patent Attorney Seki Yamashita

Claims (6)

[Claims] (1) A liquid jet recording apparatus that performs recording by ejecting a recording liquid from a recording head onto a recording material, characterized by having means for detecting adhesion of the liquid to an orifice surface of the recording head. Injection recording device. (2) The liquid jet recording apparatus according to claim 1, wherein the detection means is means for detecting a state of conduction between an electrode disposed on an orifice surface of the recording head and ink within a nozzle. (3) The liquid jet recording apparatus according to claim 1, wherein the detection means is means for detecting a conduction state between a plurality of electrodes arranged on an orifice surface of the recording head. (4) The liquid jet recording apparatus according to claim 1, wherein the detection means is an optical detection means. (5) Claims 1 and 2 further comprising means for removing liquid adhering to the orifice surface of the recording head.
, a liquid jet recording device according to claim 3 or claim 4. (6) The liquid jet recording apparatus according to claim 5, wherein the liquid removing means is a means for sucking the liquid into the nozzle by reversing the ink supply motor.